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Cross‐linked cationic polyvinyl alcohol (CPVA) is obtained by solution polymerization using vinyl acetate (VAc) and N‐(isobutoxymethyl)acrylamide (IBMA) as main raw materials and free radical co‐polymerization using glycidyl methacrylate (GMA) and dimethylaminoethyl methacrylate (DM) as modified monomers. The structure is characterized by HNMR. The effects of DM monomer on the properties of CPVA are investigated. It turns out that CPVA dispersion is a Bingham fluid with good stability. The particle size of CPVA reaches minimum and the value is 147.2 nm, which is in favor of infiltration into the paper. It is more suitable for the DM dosage ranging from 2% to 2.5% in light of the mechanical properties of CPVA film. The obtained CPVA is amorphous and the degree of crystallinity is decreased. When used as surface sizing agent for paper, the water absorption of the sizing paper reaches minimum and the folding resistance reaches maximum when DM is 2.5%. The maximum dry and wet tensile indexes of the paper are increased by 190.71% and 331.09%, respectively. SEM results shows that the larger pores between the paper fibers are filled and cross‐linked after CPVA sizing, which is beneficial to the improvement of paper strength. [ABSTRACT FROM AUTHOR]

Although styrene acrylate emulsions (SAE) have demonstrated promising applications as surface sizing agents for paper, their strengthening effect on pulp fibers in papermaking is not clear. In this study, bagasse fibers, an agricultural waste, were treated with SAE to study the influences on the mechanical properties of the produced papers. SAE copolymers with hard chain (H‐PSA) and soft chain (S‐PSA) were prepared and added to bagasse pulp slurry at concentrations of 1%–4% by weight. The findings indicated that for the soft and hard copolymers, the glass transition temperatures were 19.5 and 26.8°C and their emulsion particle sizes were 166 and 182 nm, respectively. The copolymers strengthened the produced paper by wrapping around and forming a network of chemical and physical bonds with the pulp fibers. Papers treated with 3% H‐PSA exhibited the optimum improvement in tensile strength (38 MPa) and breaking length (67 m) by 13% and 64%, respectively. Treated papers were negatively affected by UV radiation due to phenyl groups spread along the chains. The copolymers demonstrated good wet‐strength properties achieved by self‐ and co‐crosslinked networks. The prepared paper sheets showed a preference for the mechanical properties of treated samples over the untreated ones. [ABSTRACT FROM AUTHOR]

Acid‐catalyzed hydrolysis of glycosidic bonds is the most important degradation mechanism affecting cellulose‐based materials. It results in the decrease of DP and in the loss of the original mechanical properties. The neutralization of acidity is therefore one of the most efficient ways to hamper the degradation of cellulosic artworks. However, in the case of acidic and strongly degraded artifacts, in addition to deacidification, a consolidation treatment must be performed. To this aim, a new class of biopolymers, obtained by a synthetic procedure that considers the principles of Sustainable Chemistry, was investigated. Three allyl saccharide/vinyl acetate copolymers, having different molar ratios between starting monomers, were prepared using α,α'‐trehalose, and used to synthesize the corresponding allyl saccharide/vinyl alcohol copolymers. The use of saccharide derivatives as monomers improves the affinity and compatibility of the biopolymer with the artifacts to be treated. After characterization, the efficacy of the copolymers in the strengthening of degraded paper was evaluated with mechanical tests. The most effective system was thus selected for further testing. Its performance was compared to that of Klucel G®, a commercial product belonging to the class of cellulose derivatives, which are largely used in conservation practice. [ABSTRACT FROM AUTHOR]

To obtain additives that could simultaneously increase the dry strength and wet strength of paper sheets, we synthesized a series of crosslinked cationic glyoxalated polyacrylamide (GPAM) resins by using acrylamide (AM), 2-methacryloxyethyl trimethyl ammonium chloride (DMC), N-methylolacrylamide (NMA), 2-mercaptoethanol, and glyoxal as the main materials. GPAM demonstrated excellent properties and had a good strengthening ability under the following polymerization conditions: dosage of AM = 55 wt %, dosage of the cationic monomer DMC = 5.5 wt %, dosage of the crosslinking monomer NMA = 8.0 wt %, dosage of chain-transfer agent 2-mercaptoethanol = 1.0 wt %, dosage of glyoxal = 30 wt %, and charge of the initiator (ammonium persulfate/sodium bisulfite = 1 : 2) = 0.5 wt %. The products were characterized by Fourier transform infrared spectroscopy, 1H-NMR, size exclusion chromatography, and Ubbelohde viscometry. The copolymers with a viscosity-average molecular weight of approximately 26,000 and a polydispersity index of 1.460 had a much better strengthening ability. When these GPAM resins were used as paper-strengthening agents, the mechanical strength of the paper was remarkably enhanced, and the dry and wet tensile indices of the handsheets increased by 24.6 and 381%, respectively, compared with those of handsheets without GPAM. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012 [ABSTRACT FROM AUTHOR]

Aramid based on poly (p‐phenylene terephthalamide) (PPTA) is widely concerned as high‐performance materials. Herein, copolymerized aramid nanofibers (CANFs) were prepared for the first time by a direct bottom‐up polymerization method without additives. Three kinds of third monomers of m‐phenylenediamine, 4,4′‐diaminodiphenyl ether, and 2,5‐dichloro‐1,4‐phenylenediamine were separately copolymerized in PPTA and transformed into nanofiber dispersions in water medium. The characterization results revealed the relationship between the morphology of products and the structure as well as dosages of the different kinds of monomers, which was explained by the influence on conjugate regularities of the PPTA molecules. Furthermore, CANFs were used to build aramid paper blended in pure PPTA nanofibers, and the mechanical and insulation properties of composite paper were improved significantly, which would be of potential use as the new building block for aramid composite materials. [ABSTRACT FROM AUTHOR]

This study was conducted to assess the effect of the pulping by‐products crude tall oil (CTO), distilled tall oil (DTO), and tall oil fatty acid (TOFA) on dynamic water vapor sorption behavior, interfiber strength, and thermal stability of cellulosic paper‐sheets. The results were compared against those obtained in cellulose papers treated with the conventional petroleum‐derived hydrophobic agent hydrowax and in untreated ones. The tall oil treatments caused strong reduction in equilibrium moisture content of the paper‐sheets during adsorption and desorption runs. The same trend was noticed for the hydrowax‐treated papers, however, it was less pronounced than the CTO‐treated and DTO‐treated samples in the relative humidity range of 75–95%. The sorption hysteresis was considerably decreased after the treatments. The ultimate dry‐tensile strengths of the paper‐sheets were significantly reduced by TOFA and hydrowax treatments, while CTO and DTO showed comparable strength as that of untreated control. The ultimate wet‐strengths of the paper‐sheets were improved after the treatments. The thermal stability of the specimens was improved by the tall oil treatments, and the hydrowax‐treated samples illustrated lower degradation temperature than the untreated control. The results are promising for the use of tall oils as alternative hydrophobic agents of cellulosic fiber‐based products, such as wood panels and paper packaging. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47303. [ABSTRACT FROM AUTHOR]

A well‐defined glycopolymer was synthesized to investigate its properties. The glycopolymer was obtained with a narrow polydispersity by nitroxide‐mediated radical polymerization of styrene carrying acetylated lactose and by the subsequent deprotection. The cylindrical structure and helical conformation of the polymer were measured by circular dichroism (CD) spectra. The affinities of the polymers towards lectins depended on the degree of polymerization (DP), and the polymers with higher DP showed stronger affinity. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper focuses on the calculation of the interfacial tension of two systems: low‐density polyethylene with isotactic polypropylene and high‐density polyethylene with syndiotactic polypropylene. For this, three methods to measure the interfacial tension are compared: the use of Palierne's model, and Gramespacher and Meissner's model, both based on additional elasticity or long relaxation times brought by shape recovery of dispersed phase, and ab‐initio calculation, which requires the knowledge of the surface tension of the neat polymer measured at the same temperature. For that, a database collected from the literature is built in the first section of this paper, whether for the studied systems or for other systems of various olefinic homopolymers or copolymers with polypropylene. The results show the effectiveness of the Gramespacher and Meissner's model to calculate the interfacial tension of the studied systems for which the results were in agreement with ab‐initio calculation and Palierne's model. Extension of the ab‐initio calculation to olefinic copolymers was proposed. [ABSTRACT FROM AUTHOR]

Wood is an irreplaceable structural and biodegradable material, which is subject to swelling, shrinkage, significant deformation of structural elements, and products when its moisture content changes. This paper proposes wood surface modification with reactive copolymers based on glycidyl methacrylate and alkyl methacrylates to impart superhydrophobic properties with initial contact angles up to 166°. Scanning electron microscopy and energy dispersive X‐ray spectroscopy were used to study the features of polymer coating formation and to determine the modifier penetration depth, which was more than 1000 μm. It has been shown that copolymers do not fill the initial capillary system of wood. Modified wood is characterized by stable water‐repellent properties with low‐water diffusion rates, with the water absorption rate reduced by more than three times compared to that of initial wood. Polymer coatings provide water repellency, retain the appearance of original wood, and provide increased buoyancy. [ABSTRACT FROM AUTHOR]

Aiming at the problem of phase separation between thermoplastic toughener and epoxy after curing, which leads to the reduction of mechanical properties, in this paper we improve the compatibility of the two phases by introducing reactive groups into the molecular chain of thermoplastic resins, thus improving the impact strength of the epoxy system. Phenolphthalein polyether sulfone (C‐PESC) with designable and controllable carboxyl group content was prepared via SN2 nucleophilic substitution copolymerization. Further C‐PESC was evaluated for epoxy toughening, and the effects of carboxyl group content of C‐PESC on mechanical properties and thermal stability of the resin system were investigated. The results show that C‐PESC resin has good compatibility with E51 epoxy resin. Carboxyl group accelerates the dissolution rate of thermoplastic resins in epoxy and also participates in the curing reaction with epoxy to enhance the interfacial bonding ability between the toughening component and the matrix resin. The reactive toughener C‐PESC can not only improve the impact properties of E51 epoxy, but also maintain the high Tg and thermal properties of the resin system. Among them, the addition of 5 PHR of C‐PESC3 increased the impact strength of the modified resin by 45%, with uniform fracture surface and tough fracture shape. [ABSTRACT FROM AUTHOR]

In our prior paper, surface micelles with the core‐shell‐petal structure of the double hydrophilic block copolymer poly(N‐isopropylacrylamide)‐block‐poly[oligo(ethylene glycol) acrylate] (PNIPAM‐b‐POEGA) were successfully evaluated. In this work, ionic strength (under acidic conditions) and anion‐specificity effects (under neutral conditions) on the aggregation behavior of PNIPAM‐b‐POEGA at the air/water interface and the morphologies of its Langmuir–Blodgett (LB) films were systematically studied. Under acidic conditions, the salting‐out effect prevails over the electrostatic shielding effect, and the amide group shells with a slight protonation degree are covered up by the large POEGA petals. Under neutral conditions, the stretching degrees of POEGA blocks at low/moderate salt concentrations are close. At high salt concentrations, the isotherms gradually shift to large molecular areas in the order of the NaCl, Na2SO4, NaNO3, and NaSCN cases. The hysteresis degrees of the monolayers increase with the increase of salt concentrations due to the gradually increased interfacial stretching degree and compression‐induced underwater solubility of POEGA blocks. All the initial LB films of PNIPAM‐b‐POEGA exhibit isolated circular micelles with small cores. Upon compression, the LB films exhibit slightly large micelles because of the possible coalescence of some neighboring cores. [ABSTRACT FROM AUTHOR]

Grafting‐to polymer coatings are typically easy to apply, but the thickness of such coatings is typically limited to a few nanometers, which may hamper applications. This paper presents a grafting‐to coating approach that yields polymer brushes up to an unprecedented thickness of 19 nm. To this aim, an easy‐to‐apply poly(dopamine) (PDA) primer layer is optimized. PDA is an easy‐to‐apply, but highly complex and chemically not well understood primer layer. In this study, PDA is deposited on silicon substrates using several deposition protocols (pH 4–7 in presence of NaIO4, and from Tris solution at pH 8.5). The modified surfaces are characterized using X‐ray photoelectron spectroscopy, spectroscopic ellipsometry, static water contact angle measurements, and atomic force microscopy. Subsequently, block copolymers of poly(glycidyl methacrylate)20‐b‐poly(N‐isopropylacrylamide)n are attached onto the PDA films using a grafting‐to approach. The results indicate that the conditions of PDA deposition and the PDA film thickness strongly influence the stability and grafting efficiency of the block copolymers. PDA films deposited at pH 7 with NaIO4 are stable, and yield the most efficient grafting, with grafted polymer layers as thick as 19 nm. Polymer layers of such thickness are rarely achieved using grafting‐to procedures from solution. [ABSTRACT FROM AUTHOR]

Vanillic acid represents a potentially interesting bio‐based building block for the production of new aliphatic‐aromatic polymers, characterized by thermal properties similar to those of the analogous terephthalic polyesters. However, poly(ethylene vanillate) proved to be a very brittle material, probably due to a very high degree of crystallinity, and, then, not suitable for melt processing. Therefore, the synthesis of copolymers, based on vanillic acid and pentadecalactone is considered as a strategy to obtain new polymeric materials with a low degree of crystallinity, tunable properties, and better performances. The synthesis of these fully bio‐based random copolymers is successful. The thermal properties have been studied in order to correlate chemical structure and final performances. The polymers proved to be processable and films are obtained, suggesting possible applications of the copolymers in a new sustainable flexible packaging. [ABSTRACT FROM AUTHOR]

Metal catalyzed polymerizations are among the most important chemical reactions, accounting for the production of about 400 million tons per year of polymeric materials, 50 % of which are polyolefins. The CIRCC research units at the University of Salerno, founded by the late Professor Adolfo Zambelli, a coworker of Giulio Natta and a pioneer in the studies of stereospecific polymerization catalysts, has a consolidated expertise in this field. Although often considered a "mature" area of research, olefin polymerization catalysis continues to drive great interest of both industrial and academic scientists. On the other hand, strong political and economic pressure toward the development of "green" and possibly biodegradable alternatives to olefin‐based polymers stimulated our group to direct increasing research efforts in the area of sustainable polymers. In this perspective, we focus on the most recent work from the CIRCC research units involved in homogeneous catalysis for polymerization of a variety of monomers, with the aim to address how the concepts and the expertise developed for olefin polymerization can be applied to the development of different metal‐catalyzed polymerizations and copolymerizations. Of course, although the results are discussed in the frame of the most important literature contributions, a comprehensive review of such a wide and diversified topic is out of the scope of the paper. References to reviews covering the different types of metal catalyzed polymerizations are provided in each chapter. [ABSTRACT FROM AUTHOR]

Thiol‐ene radical coupling reaction exhibits high chemical selectivity and rapid kinetics. In particular, the experiment of photoinitiated reaction has the advantages of facile operation and short reaction time. However, there are few reports on its application in macromolecular thiol‐ene coupling reaction in the presence of polymeric chains containing amine moieties. On the one hand, an amine agent itself may be involved in photoreaction; and on the other hand, amine moieties can create an alkaline environment, which may retard thiol‐ene radical reaction. In this paper, a well‐defined A(B‐L)2 type miktoarm star copolymer unit is investigated and synthesized, together with further A(B‐L)2C type one, by employing macromolecular thiol‐ene radical coupling reactions. In two copolymers, A, B, and C are poly(ε‐caprolactone) (PCL), poly(2‐(diisopropylamino) ethyl methacrylate) (PDPA), and poly(2‐methacryloyloxyethyl phosphorylcholine) (PMPC) arms, respectively, and L is terpyridine (tpy) ligand group and locates at the end of B arm. Especially, the synthesis of A(B‐L)2 type molecular architecture involved that a PDPA reactant (tpy‐PDPA‐SH) contains both a thiol end‐group and pendant tertiary amine moieties. Herein, such a macromolecular thiol‐ene radical coupling reaction is investigated and a robust synthesis strategy is reported. [ABSTRACT FROM AUTHOR]

High‐value grades of ethylene‐acrylic acid (EAA) and ethylene‐acrylic ester copolymers have been producing produced from ethylene, acrylic acid (AA), and the alcohol derivative via radical reaction in autoclave reactor at a temperature of 150‒230 °C and pressure of 150–300 MPa. In this paper, EAA and its ester derivatives are originally created from the 5‐substituted cyclooctenes (COE) with side chains of carboxylic acid or ester derivatives by ring‐opening metathesis polymerization (ROMP) at normal temperature and pressure. Especially, the controllable insertion of side chain is effectively achieved by altering the molar ratio of COE and 5‐substituted COE. Furthermore, the polar carboxyl groups (ester groups) have a detrimental effect on the order assigns of the linear backbone and thus hindered crystallization, indicating relatively lower crystallizing and melting temperature with an increase in the content of side chain. As the amounts of polar groups raised, the stiffness of chain segments enhanced, thereby leading to an elevation in the copolymer's energy storage modulus (E') and glass transition temperature (Tg). Moreover, the Flynn‐Wall‐Ozawa (FWO) technique is employed to characterize and fit the non‐isothermal crosslinking kinetics of the ethylene‐acrylic ester derivatives, and the crosslinking activation energy is determined to lie between 97 and 140 kJ mol−1. [ABSTRACT FROM AUTHOR]

Hydrophobically modified cellulose is prepared in this research by conducting atom transfer radical polymerization (ATRP) of methacrylate substituted coumarin monomer on initiator grafted cellulose. The photocrosslinking of uniformly grafted coumarin on cellulose surface is applied to improve the water vapor barrier property of the film. The water vapor transmission rate (WVTR) of films prepared from modified cellulose with varying grafting density, grammage, and photocrosslinking time is studied. By increasing the amount of crosslinking within the grafted cellulose film, we succeeded in reducing WVTR. The WVTR is reduced from 160 to 20 g/m2/day using a sheet of 60 g/m2 after crosslinking. The effect of grafting density on WVTR is also analyzed to observe that the higher the grafting density, lower the WVTR of the sheet both before and after crosslinking. Furthermore, free ATRP polymerization (without cellulose) and polymerization using a sacrificial initiator of the monomer are conducted to estimate the dispersity of the polymer on cellulose. The monomer, free polymer and cellulose grafted polymers are analyzed for the composition, thermal, morphology, photoresponsive behavior, and polymerization quantification using NMR, FTIR, UV–Vis, TGA DSC, GPC, SEM, ICP‐MS. It is concluded that the inter and intramolecular photo dimerization of coumarin molecules forms a hydrophobic crosslinked hyper network in the polymer sheet, which improves its barrier property. [ABSTRACT FROM AUTHOR]

In this paper, a new kind of environmental friendly double‐network gel material was prepared. The first network structure was formed by the graft copolymerization of sodium lignosulfonate (LS) and acrylic acid (AA), and the second network structure was formed by the chelation reaction of sodium alginate (SA) and carbide slag clarified solution (Ca2+). Through an orthogonal experiment, the effects of raw material addition on the compressive strength and apparent viscosity of the gel were analyzed. According to the analysis results, the optimal experimental ratio was obtained, i.e., 2 wt% of LS, 0.25 wt% of SA, 15 wt% of AA, 0.1 wt% of MBA and 0.3 wt% of APS. Furthermore, the structure of the gel are characterized by FTIR, XRD, SEM, XPS, and TG‐DTG, and the results prove that the gel successfully polymerized and a stable three‐dimensional network structure is formed. The results of water absorption experiment disclose that the gel is sensitive to ions and pH, and the water absorption rate reaches 121.25 times. In addition, the results of the air leakage experiment and fire extinguishing experiment show that the gel can effectively cover the surface of crushed coal and densely fill the gaps, demonstrating a good plugging capability and fire extinguishing capability. [ABSTRACT FROM AUTHOR]

Polyacrylamide (PAM) microsphere has been widely used in the field of profile control to reduce water cut in heterogeneous reservoirs. However, its mechanical strength and plugging ability are still needed to be improved. In this paper, a core‐shell structure and surface‐hydrophobic polyacrylamide M‐P(AM‐PEP) microsphere was prepared by using acrylamide (AM), block polyether macro monomer (PEP) and modified SiO2 with double bond on the surface as monomers through dispersion polymerization. After the optimization of synthesis conditions, the results of SEM and TEM confirmed that M‐P(AM‐PEP) microsphere had the nano‐scale spherical shape and the inorganic core/polymer shell structure, while the contact angle test results showed that M‐P(AM‐PEP) microsphere had the surface‐hydrophobicity. Swelling experiments presented that the size of M‐P(AM‐PEP) microsphere can be increased by 6 times and had obvious self‐gathering behavior. The inorganic core and self‐gathering behavior are helpful for improving mechanical strength and plugging ability of PAM microsphere, respectively. Profile control and oil recovery improvement experiment showed that injecting 0.1 PV M‐P(AM‐PEP) microsphere can decrease the water cut and increase the oil recovery of 17.95%. This new microsphere could be an efficient technology for the profile control in the heterogeneous reservoir. [ABSTRACT FROM AUTHOR]

In this paper, a series of poly(ethylene terephthalate‐co‐2,6‐naphthalate) (PETN) (co)polyesters with different naphthalene ring contents were synthesized via a two‐step transesterification and polycondensation. The effects of the monomer compositions on the sequence distribution, crystallization, mechanical, thermal, and barrier properties of the (co)polymers were investigated systematically. The results showed that the introduction of naphthalene ring units (NDC) changed the sequence length of the PETN and disrupted the orderly arrangement of the PETN molecular chains, thus affecting the aggregated structure and properties of the copolymer. When the NDC content was less than 30%, the PETN copolymers displayed good ductility and higher yield strength comparable to PET, and the heat distortion temperature (HDT), thermal stability properties, and barrier properties of the copolymer were also improved. In addition, the diffusion kinetics of water and oxygen molecules in the (co)polymer were investigated by the MS program simulation software. The differences in gas barrier properties of the different PETN (co)polymers were explained at the molecular level. This study provides a systematic theoretical basis and comprehensive practical guidance for the preparation of high‐performance copolyester materials. [ABSTRACT FROM AUTHOR]

This paper explores both physical ageing of polyvinylidene fluoride (PVDF) and its copolymers with hexafluoropropylene (HFP). Water ageing and annealing are shown to have a negligible influence on mechanical properties. Chemical ageing is thus expected to be the main source of long‐term degradation. The nature of associated chemical trackers is discussed but it seems clear that their fraction is very slow for low temperature thermal ageing. [ABSTRACT FROM AUTHOR]

In this paper, we highlight the uniqueness of nanoporous film‐coated electrodes as electrochemical sensing platforms. Specifically, we focus on discussing electrodes coated with insulator‐based monolithic films comprising vertically‐oriented, rigid cylindrical nanopores of uniform diameters (2–200 nm). The electrode coating results in the formation of an array of recessed nanodisk electrodes, and thus we named them recessed nanodisk‐array electrodes (RNEs). We first summarize the properties of nanoporous films commonly used for RNE fabrication, including nanoporous anodic alumina membranes, track‐etched polymer membranes, block copolymer‐derived nanoporous films, and mesoporous silica films. Subsequently, we discuss representative works that take advantage of the uniform size/shape of the nanopores for enhancing electrochemical detection selectivity and sensitivity. RNE‐based sensors measure faradaic currents from redox‐active analytes or exogenously‐added electroactive species that penetrate through the nanopores, or those from redox‐active moieties tethered to the surface of the nanopores or underlying electrodes. The enhanced detection selectivity of these sensors is attributed to the preferential partitioning of analytes into the nanopores or steric/electrostatic exclusion of interfering species. In particular, the uniform sizes/shapes of RNE nanopores play key roles in their higher molecular sieving selectivity and also in the better control of the detection selectivity based on electrostatic/chemical interactions. The detection sensitivity of RNE‐based sensors can be improved by tailoring the chemical environments of the nanopores for analyte preconcentration or for steric/electrostatic manipulation of the dynamics of redox‐tagged binding moieties. These unique characteristics of RNEs, in addition to the mitigation of electrode fouling by the nanoporous films, will enable the development of pretreatment‐free electrochemical sensors for complex matrix solutions. [ABSTRACT FROM AUTHOR]

Aldimine derivatives chromophores grafted on polyacetylene oligomers were first designed to investigate the nonlinear optical (NLO) response of the resulting materials using CAMB3LYP method. The effects of different factors such as the chain length separating the substitutions as well as the configurations and the orientations of these latter, were examined and discussed. In a second part of this paper, NLO responses, in particular the static hyperpolarizabilities of polyvinyl oligomers substituted by aldimine chromophores via carboxylic groups and by pyrrolidone groups were calculated for different configurations. The stability and the hydrogen bonding in each oligomer were also discussed. [ABSTRACT FROM AUTHOR]

Functional Materials and Devices Division (FMDD) With the progress of the daily lifestyle of modern human being, the need for flexible dielectric energy storage devices for high field applications has become inevitable. PVDF and its co‐polymers, which exhibit excellent flexibility, high breakdown strength, good piezoelectric and ferroelectric properties and low cost, have become very useful in this purpose and hence being investigated widely all over the world. Different strategies including versatile device fabrication techniques and momentous materials engineering have been employed to promote the energy storage characteristics of PVDF based composites. In this paper, we review the current trend of research in the field of PVDF based energy storage devices with the main focus on the strategies involved in enhancing their energy storage performance. Upon extensive literature survey, it has been found that the breakdown characteristics of the composite films are the main determining factor of their high field energy storage applications. The strategies, which can enhance the said performance of PVDF‐based composites, have been elaborately discussed here step‐by‐step and the fruitful approaches for the desired performance enhancement have been proposed. Considering the numerous attraction of research in this field, the gaps and huge future scopes of research have also been comprehensively discussed here. [ABSTRACT FROM AUTHOR]

A novel nanocomposite leather‐finishing agent (denoted as H‐TiO2@SDS‐rGO/F‐PBMA) composed of fluorinated copolymer (denoted as F‐PBMA) matrix using methyl methacrylate (abbreviated as MMA), butyl acrylate (abbreviated as BA) as well as acrylic acid (abbreviated as AA) as monomers and H‐TiO2@SDS‐rGO composite nanoparticles as nano‐additives were successfully fabricated by aqueous emulsion polymerization in this paper. The hollow TiO2 nanoparticles (denoted as H‐TiO2) were firstly prepared with tetrabutyl titanate as titanium source wall and tetraethyl silicate as silicon source core through an alkali etching method, and then they were compounded with reduced graphene oxide (rGO) modified by sodium dodecyl sulfate (denoted as SDS‐rGO) for obtaining H‐TiO2@SDS‐rGO composite nanoparticles. Fourier transform infrared spectra, X‐ray diffraction, Raman spectra, scanning electron microscopy, and nuclear magnetic resonance spectra were used to characterize the structure and morphology of different samples. The experimental results reveal that the nanocomposite leather‐finishing agent not only has excellent transparency, but also endows sheepskin better weather resistance, thermal stability, hydrophobicity and mechanical properties compared with traditional leather finishing agents. [ABSTRACT FROM AUTHOR]

Microplastic has become the focus of environmental pollution recently, especially in seawater. Due to its high crystallinity and hydrophobicity, the degradation rate of poly(butylene succinate) (PBS) is slow. In this paper, a series of poly(butylene succinate‐co‐diethylene glycol succinate) (PBSD) copolymers were synthesized by melt‐polycondensation in order to improve the nonenzymatic hydrolysis of PBS. The contact angle and water uptake content of copolymer were increased obviously when the regular crystalline structure of chain segment was disturbed by diethylene glycol. Rheological tests revealed the microphase separation structure occurred at 130°C. The tensile strength of PBSD40 copolymer was 15 MPa and the elongation at break was more than 700%, and the decomposition temperature was above 370°C. The weight loss of PBSD60 copolymer in acid condition was 98.6% after 49 days at 50°C. However, in neutral condition and simulated seawater, the weight loss was less than 10%. Acid and alkaline catalyzed the hydrolysis of ester bonds. Some holes and cracks appeared at the surface of the samples after degradation from SEM analysis. Thus, PBSD copolymers have the potential to serve as promising water degradable materials. [ABSTRACT FROM AUTHOR]

This article aims to outline the current progress in the field of energetic copolymer binders for composite solid propellants (CSPs). Propellants, which are a type of energetic material, are used to generate thrust in rockets and missiles, and they are generally less sensitive than explosives. The common formulations of CSPs contain several different chemical compounds that are typically bound together by a polymeric matrix to form a continuous solid. The use of inert polymers, however, does not enhance the overall specific impulse of the propellant. Energetic copolymers have emerged as a compelling category of binders for CSPs in recent years, offering potential advantages over traditional binders such as improved performance, enhanced safety, and increased manufacturing efficiency. The paper reviews the various types of energetic copolymer binders that have been developed, their potential advantages and drawbacks, and the current challenges and opportunities in the field. It suggests directions for future research and development and aims to provide a useful resource for researchers and practitioners interested in the use of energetic copolymer binders toward CSPs. [ABSTRACT FROM AUTHOR]

In this paper, the copolymerization of saccharin methacrylamide (1) with conjugated dienes [2,3‐dimethyl butadiene (DMBD) and isoprene (IP)] as comonomers toward advanced sequence control is studied. Both monomers are consumed at the same rate in the copolymerization despite the lack of homopolymerization ability of 1, indicating that the alternating copolymerization likely progresses. The resultant copolymers are transformed into methyl methacrylate (MMA)‐diene alternating copolymers via direct methanolysis reaction for the copolymerization solution. The alternating sequence is characterized by NMR analyses in comparison with the corresponding statistical copolymers. As for the copolymer with IP, the remaining carboncarbon double bonds are hydrogenated for the synthesis of advanced sequence‐controlled polymer, MMA‐(propylene‐ethylene) alternating‐copolymer. [ABSTRACT FROM AUTHOR]

Large bone defects due to accidental injuries and fractures as well as the mismatch between the implant material and the defect site are major problems in biomedicine. Bone tissue engineering offers a solution to this problem. In this paper, a series of three‐dimensional porous composite scaffolds with shape memory were prepared using polycaprolactone and polytetrahydrofuran as soft segment materials, hexamethylene diisocyanate as hard segment materials and amorphous calcium phosphate/calcium citrate (CAP) as inorganic fillers. The scaffolds have tunable mechanical properties, melt temperature, surface wettability, a pore size range of 100–800 μm and a high degree of connectivity. In vitro mineralization showed good mineral deposition and energy dispersion spectrometer displayed uniform distribution of Ca and P elements on the surface. The composite scaffold exhibited good shape memory properties at 37°C. The shape fixation rate (Rf) and shape recovery rate (Rr) were maintained at 94.1% and 94.4% after five compression cycles. The resulting scaffold promoted MG63 cell proliferation to some extent. The scaffold is expected to be used clinically for the treatment of large bone defects. [ABSTRACT FROM AUTHOR]

The Polish TU 154M plane, Polish Air Force Flight 101, had crashed near Smolensk on 10th of April 2010. The crash was investigated by The Interstate Aviation Committee, whose conclusions were questioned by a number of Polish scientists. The cause of the crash still appears to be incompletely documented and requires additional evidence. In this paper, investigations of a solid material eluted from a piece of cloth of one of the victims of the crash are described. High resolution mass spectrometry was applied to analyze the soot left after controlled ethylene oxide (EO) explosions, performed under different conditions. These included electric ignition of EO vapors in a large volume steel container, and explosions of glass tubes filled with liquid EO, stimulated by thermally initiated explosions of pentaerythritol tetranitrate (PETN). One of these explosions was conducted in the vessel used for the electric ignition of EO and the other in a hermetically locked, small volume container. It was shown that the soot comprises a set of C2H4O homopolymers and copolymers whose characteristic MS patterns are condition‐dependent. The MS spectrum of the postcrash sample referred to above reveals a number of polymers that are also present in the soot obtained in PETN‐initiated ethylene oxide explosions. It can be concluded that the piece of cloth was subjected to an EO explosion initiated by an explosion of energetic material, possibly PETN. Similar control experiments with ethylene glycol (EG) showed that the polymers identified in the investigated postcrash sample could not originate from exploding EG. [ABSTRACT FROM AUTHOR]

To relate the mechanical responses of hard–soft copolymer systems with their microstructures, a coarse‐grained molecular dynamics approach is employed, and mechanical properties of both hard and soft domains are calculated. We first investigate the enhancement mechanism of hard domains under tensile and shear loading conditions with pressure. The energy factor that denotes the interaction between hard beads dominates the microphase separation and morphology. Our numerical experiments show that pressure is the most crucial factor in shear‐under‐pressure tests, with larger pressure leading to higher shearing resistance of the copolymers. The viscoelastic behaviors of hard–soft copolymers are computed from the stress autocorrelation function. The stress relaxation indicates that the soft matrix is in a rubbery state at room temperature while hard domains are "glass‐like" and can be viewed as elastic solids in a macroscale model. In addition, local elastic constants of hard domains are computed using the stress–strain fluctuation method with purely local stress and local strain. Those results can be used as inputs for macroscale models for copolymers and can provide guidelines for designing polymeric materials. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1552–1566 A bead‐spring coarse‐grained MD model is built with different compositions and hard–hard interactions to study the enhancement mechanism of hard domains in thermoplastic polyureas and polyurethanes (TPUs). Based on the model, TPUs' stress relaxation is also calculated. Further, viscoelastic master curves can be obtained by transferring the stress relaxation to frequency domain and be used in continuum scale models. In addition, local modulus of hard domains is computed as the last part of the paper. [ABSTRACT FROM AUTHOR]

As the development of oilfield exploitation, more and more oil in water (O/W) emulsion was produced, thus efficient reverse demulsifier becomes increasingly important. In this paper, a series of novel reverse demulsifiers (R‐PED1 ~ 4) with the characteristics of polyacrylate and polycation were prepared. The structure of the product was verified by IR specter and 1H NMR. The thermal stability was studied with TGA and the molecular weight was obtained by GPC. Field evaluation results showed that the oil content in produced liquid after R‐PED4 treatment can be reduced from 1550 to 81 mg/L at R‐PED4 dosage was 50 mg/L. Furthermore, the demulsification mechanism of R‐PED was discussed. The R‐PED has good surface/interfacial activity. It can effectively reduce the oil–water interfacial film strength and reduce the zeta potential of oil droplets, which is beneficial for the coalescence of oil droplets. Especially, the interaction force between oil droplets was measured by the optical tweezers. R‐PED4 can increase the attraction force between oil droplets. Consequently, the contact time of oil droplets during the demulsification process can be prolonged and the coalescence of oil droplets also can be effectively promoted. The novel reverse demulsifier offers a new option for the oilfield produced liquid treatment. [ABSTRACT FROM AUTHOR]

Succinic acid is an important synthetic monomer but it is difficult to use it as a precursor for synthesizing high molecular weight polyamide, due to its tendency to perform intra‐cyclization reaction at high temperature. In order to solve this problem, in this paper, the direct solid‐state polymerization (DSSP) method with the initial reactant, nylon salt which was composed of 1, 5‐diaminopentane, succinic acid, and terephthalic acid, was applied to synthesize the bio‐based copolyamide PA 5T/54. In comparison with the conventional melting polymerization method, the DSSP method can prevent the cyclization reaction of succinic acid effectively due to the lower reacting temperature as well as the restriction effect of the nylon salt. As a result, the product fabricated by DSSP method has higher molecular weight and much lighter color from red to white. Therefore, the DSSP method is advantageous for the synthesis of the polymers or copolymers composed of the succinic acid as the monomer. Furthermore, the polymerization mechanism proposed in this work can serve as a guidance for the design of the molecular structure and control of the polymerization process. [ABSTRACT FROM AUTHOR]

One of the essential components in this era of the Internet of Things (IoT) and wearable technologies, is a flexible and high performance resistive random access memory (ReRAM) device. In this paper, the authors propose a new copolymer‐based ReRAM device that is realized using an initiated chemical vapor deposition (iCVD) process. The 7‐nm‐thick copolymer ReRAM device exhibits endurance properties as high as 105 and switching power as low as 438 µW. The strong endurance of the copolymer‐based ReRAM device originates from the properties of the robust poly‐1,3,5‐trivinyl‐trimethyl‐cyclotrisiloxane dielectric film, while its low on‐current at the operating voltage is attributed to the properties of the poly‐2‐hydroxyethyl methacrylate dielectric with the Al electrode. The proposed ReRAM also has the additional advantage of forming‐free switching characteristics. [ABSTRACT FROM AUTHOR]

Pressure‐sensitive adhesives (PSAs) are made from soft, irreversibly lightly crosslinked polymers. Even after removal from surfaces, they retain insoluble networks which pose problems during the recycling of glass and cardboard. Herein, degradable PSAs are presented that provide the required performance in use but have networks that can be degraded after use. A series of copolymers was prepared through radical copolymerization of n‐butyl acrylate, 4‐acryloyloxy benzophenone (ABP) photo‐crosslinker, and dibenzo[c,e]oxepin‐5(7H)‐thione (DOT) to provide degradable backbone thioesters. The optimum tack and peel strengths were found for molar contents of 0.05 mol% ABP and 0.25 mol% DOT. Degradation of the backbone thioesters through aminolysis or thiolysis led to the full dissolution of the networks, loss of adhesive properties of films (decreases in the measured tack and peel strengths), and the quick detachment of model labels from a substrate. Inclusion of DOT into PSAs offers a viable route toward degradable and recyclable packaging labels. [ABSTRACT FROM AUTHOR]

For a probe tack test for a pressure‐sensitive adhesive (PSA) under the conditions of light contact pressure and short contact time, probes with shapes and surface roughnesses suitable to achieve better wettability were investigated. A smooth, polished probe that became slightly convex at its center was found to be superior to flat‐ended. High surface roughness decreased tack. Debonding observations showed that fibrillation started from the probe edge and extended to the center. The fibril grew, without peeling, until the peak of the force–displacement curve was reached. After the peak, the fibril growth and peeling advanced simultaneously. The fibrillation was important to tack development. The test conditions necessary to observe the deformation behavior of PSA tape with sufficient interfacial adhesion were investigated. The system was preheated at 60°C for 1 h after the probe and PSA tape contacted each other, and was then cooled. The PSA performance of crosslinked random copolymers poly(n‐butyl acrylate‐acrylic acid) (A) and poly(2‐ethylhexyl acrylate‐acrylic acid) (B) were compared. A shoulder formed by fibrillation after the peak in the force–displacement curve was observed only for B. Copolymer B exhibited better interfacial adhesion and deformability. The preheating method was found to be useful for characterizing PSAs. [ABSTRACT FROM AUTHOR]

In this paper, a novel kind of PMMA copolymer, P(MMA‐co‐MAA‐co‐SPMA), with permanently antistatic, high toughness, and high transparent properties, was synthesized via radical copolymerization. Herein, we selected the appropriate compatibilizer α‐methacrylic acid (MAA) and release agent (lauryldiethanolamine) through the calculation of solubility parameters for industrial mass production. What is more, the polymer's molecular weight was increased by improving the polymer's synthesis process. The structure and properties of the obtained copolymer were characterized. With 0.6 wt% of the 3‐sulfopropyl methacrylate potassium salt (SPMA), the copolymer exhibits nearly unchanged transparency with neat PMMA, and its unnotched impact strength reaches 16 kJ/m2. The surface resistance of the copolymer could be reduced to 1010 Ω, which could be considered as antistatic materials. Finally, the antistatic mechanism was analyzed. The main reason is that the hydrophilic group absorbs water to form a conductive layer on the surface, and 3‐sulfopropyl methacrylate potassium salt (SPMA) is an ionic monomer that can form ion channels in water molecules, further accelerating the leakage of accumulated electrostatic charges and improving the antistatic properties of the copolymer. The method of selecting compatibilizers and release agents through solubility parameters provides more opportunities for the development of PMMA with excellent comprehensive performance. [ABSTRACT FROM AUTHOR]

Copolymerization of cationic monomer and nonionic macromonomer in water‐ether mixture solution is useful for preparing the functional polymer. Copolymer of diallyldimethylammonium chloride (DMDAAC) and a nonionic block polyether macromonomer (PEP‐65) has been found that has very well reverse demulsification performance, but the polymerization phenomenon cannot be described by any reported polymerization method. In this paper, the copolymerization behavior including polymer mechanism, polymerization kinetics, and reactivity rate of DMDAAC and PEP‐65 in the mixture solution of water and propylene glycol methyl ether (PGME) was studied for explaining the special copolymerization phenomenon and its flotation performance for treating oily wastewater was also investigated. The results showed that DMDAAC‐PEP‐65 copolymerization in water‐PGME mixture solution has four stages and has both characteristics of emulsion polymerization and dispersion polymerization. In addition, the copolymer also has excellent flotation performance. [ABSTRACT FROM AUTHOR]

The structural changes in the hydrolyzed polyacrylamide (PAM) under different saline conditions show significant effects on the rheological properties. At the higher shear rates, these conformational changes cannot be discerned in the shear rheological field but the extensional rheology can probe the polymer's microstructure can provide a better description. In this paper, two types of polymers: co‐hydrolyzed PAM and post‐hydrolyzed PAM were tested under different saline conditions. The polymer conformation results were interpreted to ascertain the underlying mechanisms of polymer and cation interactions and their effect on the extensional properties. The results showed that the interactions of polymer chains with divalent cations lead to the formation of the cross‐linked chelating structures corresponded to the narrow molecular weight distribution (MWD) with a lower radius of Gyration (Rg). However, the uniform carboxylate ion density across the co‐hydrolyzed PAM restricted shrinkage of the polymer chains after interactions with cations showed the high strain hardening due to polymer chain entanglement at high Hencky strain. Whereas, monovalent cation interactions with the carboxylate groups resulted in the monodentate structures that sustained the broader MWD that explains the observed higher strain hardening and extensional relaxation time. [ABSTRACT FROM AUTHOR]

The aim of this work is an in‐depth study of the stability of solutions of block copolymers with respect to both micro‐ and macrophase separation. For this purpose the correlation functions of block copolymers of various architectures are calculated as well as the critical values ​​of the wave number and Flory Huggins parameter at which a certain type of separation are estimated. As the result, the Lifshitz lines are built. Unlike some preceding papers dealing with the Lifshitz lines in the space of some thermodynamic parameters like polymer volume fraction, temperature, and composition, this consideration here concerns the space of some energetic (molecular) parameters related to the Flory–Huggins interaction parameters. In other words, this study answers a non‐trivial problem in which repeated units are to be chosen to synthesize such a block copolymer of a given architecture that its phase separation in a prescribed (micro‐ or macro) way would be guaranteed. A method is proposed for calculating the Lifshitz lines delimiting the regions of macro‐ and microphase separation in solutions of both diblock copolymers and copolymers of a more complex architecture. [ABSTRACT FROM AUTHOR]

Composites of ZnO and conjugated polymers find applications in removal of polluting dyes from industrial wastes. The choice of functionality and repeating unit of polymer is important to improve the efficacy of the process. While heterocyclic diketopyrrolopyrrole (DPP) ‐based polymers are often considered as the most promising donor moiety in traditional bulk heterojunction solar cell devices, benzothiadiazole‐based polymers are reported to show the best performance as photosensitizer for dye degradation. In this paper, we report for the first time the preparation of copolymers containing both the above mentioned heterocyclic repeating units linked directly or by a double bond. We were delighted to observe broad spectrum of substantial light absorption from UV to NIR range and a low band gap for one of the polymers, the main reason behind higher efficacy in dye removal under sunlight. Finally, we studied the efficacy of the polymers as photosensitizer for ZnO promoted dye degradation process which showed almost a complete degradation of a model dye only within two hours, one of the best results reported recently using the conjugated polymers. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, a hydrophobic monomer (HM) that has a cationic double alkyl-substituted group bonded to the nitrogen atom was first synthesized. Then a hydrophobic poly(vinyl alcohol) (PVA) was prepared by a radical solution copolymerization of vinyl acetate (VAc) with the HM followed by an alcoholysis reaction in alkaline conditions. The structures of HM and hydrophobically modified PVA (H-PVA) were confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The effect of hydrophobic cationic segments on crystallization behaviors, mechanical properties, morphology, solution viscosity, and hydrophobic property were investigated. The results indicated that the crystallinity decreased from 37.2% of pure PVA to the minimum 23.2% of H-PVA with the incorporation of 1.15 mol % HM. The thermal decomposition temperature of H-PVA increased by about 50 °C compared with that of pure PVA. The viscosity of the H-PVA solution was several times higher than that of the corresponding unmodified PVA solution over the whole shear rate range, which demonstrated that the H-PVA had good shear-resistance ability. Furthermore, the contact angle was significantly increased from 55.1° to 115° with the incorporation of only 0.83% HM, which illustrated that the H-PVA had high hydrophobicity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43888. [ABSTRACT FROM AUTHOR]

This paper analyzes data from experiments on simple polymer chains. It measures the extent to which a particular monomer prefers to link with another of the same type. To analyze the data, it derives the likelihood function for a two-state Markov model in which only the number in each state, but not the order, is observed. This technology is applied to a data set on which experimenters mixed lactic-glycolic monomers with a known proportion of a contaminant consisting of an extra lactic acid. The resulting copolymers were subjected to matrix-assisted laser desorption ionization mass spectrometry. This records the number of copolymers at each atomic weight, which can be associated with a given length of copolymer and number of contaminant monomers. Analysis of the data shows that the proportion of contaminant monomers exceeded the proportion of experimentally induced contaminant. Maximum likelihood estimates using the data show that lactic-glycolic monomers show a positive affinity for the contaminant. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Considering the inadaptability of traditional anodic bonding to polymer materials, the flexible anodic bonding process is developed. The bonding characteristics of the dynamic intelligent electric fields with the low‐temperature plasma surface treatment to polymer and ultrasonic‐assisted preconnection before bonding are very suitable for the anodic bonding of polymer elastomer to aluminum (Al) sheet. A series of composite polyurethane elastomer cathode materials (CPECs) with good bonding properties are prepared and characterized. The highest ionic conductivity of CPECs can reach to 2.7 × 10−3 S/cm (CPEC2) at 75°C. After bonded, it is determined that a uniform and dense intermediate bonding layer showed by SEM is formed between CPECs and Al. In addition, different elements including C, O, F, S, and Al are clearly identified by EDS in the bonding layers, showing that the process of flexible anodic bonding has accompanied the directional migration of ions. The maximum tensile strength of bonding layer for CPEC2 and Al (CPEC2‐Al) is up to 2.03 MPa. It is proven that the developed flexible anodic bonding can effectively improve the joint quality and reliability for polymer elastomer materials. All these results of anodic bonding are more potentially valuable to the packaging of flexible devices. [ABSTRACT FROM AUTHOR]

Molecular weight distribution of polymers, termed dispersity (Đ), is a fundamental parameter for determining polymer material properties. This paper reports a novel approach for controlling Đ by exploiting a temperature‐selective radical generation in organocatalyzed living radical polymerization. The polymers with tailored Đ were synthesized in a batch system without the assistance of an external pump. A unique aspect of this approach is that Đ was tuneable from 1.11 to 1.50 in any segment in diblock, triblock, and multiblock copolymers and in any form of star and brush polymer without segmental or topological restriction. This approach is amenable to various monomers and free from metals and thus attractive for applications. The approach also generated polymer brushes on surfaces with tailored Đ. An interesting finding was that the polymer brushes exhibited unique interaction with external molecules, depending on the Đ value. Brush up: A novel approach for modulating polymer dispersity was developed. It is based on temperature‐selective organocatalyzed living radical polymerization and enabled dispersity modulation in any segment in linear and branched block copolymers as well as polymer brushes. A dispersity‐dependent size‐exclusion effect to external molecules was observed for the polymer brushes. [ABSTRACT FROM AUTHOR]

Thiophene and p‐phenylenediamine were utilized as monomers to prepare low band gap copolymer and nanocomposites with core–shell construction by a simple in situ emulsion polymerization. Different devices such as Fourier transform infrared, X‐ray diffraction, scanning electron microscopy, thermal gravimetric analysis, dynamic light scattering and vibrating sample magnetometer (VSM) were used for characterizing the copolymer and nanocomposites. Band gaps were estimated from Cyclic voltammetry to be 2.1 − 1.7 eV for copolymers and nanocomposite. The results that obtained by measuring the conductivity with Four‐probe method illustrated that the electrical conductivity of the nanocomposites is considerably higher than the copolymer which is dependent on the Fe content and doping degree. The nanocomposites showed superparamagnetic behavior with high‐saturated magnetization (Ms = 10–16 emu/g). The direct electrochemistry of myoglobin (Mb) entrapped in the Nafion film on a glassy carbon electrode modified with synthesized nanocomposite had been investigated in this paper. Cyclic voltammetric results showed that a pair of well‐defined quasi‐reversible redox peaks appeared in the pH 7.0 phosphate buffer solution, which was ascribed to the direct electron transfer of Mb heme Fe(III)/Fe(II) redox couples. Also, the antioxidant activity of new nanocomposites was measured by using 2, 2‐diphenyl‐1‐picrylhydrazyl assay. POLYM. COMPOS., 40:1034–1042, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The ability to control the external porosity and to tune the dimensions of the macropore size on multiple length scales provides the possibility of tailoring the monolithic support structure towards separation performance. This paper discusses the properties of conventional polymer–monolithic stationary phases and its limitations regarding the effects of morphology on kinetic performance. Furthermore, guidelines to improve the macropore structure are discussed. The optimal monolithic macropore structure is characterized by high external porosity (while maintaining ultra‐high‐pressure stability), high structure homogeneity, polymer globule clusters in the submicron range, and macropores with a diameter tuned toward speed (small diameter in the 100–500 nm range using short beds) or efficiency (larger macropores in the range of 500 nm–1 μm allowing the use of longer column formats). Finally, promising approaches to control the morphology are discussed. [ABSTRACT FROM AUTHOR]

Supramolecular self-assembly offers routes to challenging architectures on the molecular and macroscopic scale. Coupled with microfluidics it has been used to make microcapsules--where a 2D sheet is shaped in 3D, encapsulating the volume within. In this paper, a versatile methodology to direct the accumulation of capsule-forming components to the droplet interface using electrostatic interactions is described. In this approach, charged copolymers are selectively partitioned to the microdroplet interface by a complementary charged surfactant for subsequent supramolecular cross-linking via cucurbit[8]uril. This dynamic assembly process is employed to selectively form both hollow, ultrathin microcapsules and solid microparticles from a single solution. The ability to dictate the distribution of a mixture of charged copolymers within the microdroplet, as demonstrated by the single-step fabrication of distinct core-shell microcapsules, gives access to a new generation of innovative self-assembled constructs. [ABSTRACT FROM AUTHOR]

ABSTRACT: Frontal polymerization (FP) is applied for the synthesis of β‐cyclodextrin/poly(vinylimidazole‐co‐N‐vinylcaprolactam‐co‐acrylic acid) (β‐CD/P(VI‐co‐NVCL‐co‐AA)) copolymers. The dependence of frontal velocity and temperature on the initiator and cross‐linker are discussed. The synthesized copolymers have been characterized by Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The thermo‐pH dual‐stimuli responsive behavior of the hydrogel is determined by swelling measurement at different temperatures and pH values. Besides, the hydrogels show intrinsic self‐healing behavior and their healing efficiency is determined by the mechanical tests. Interestingly, we integrate FP with microfluidic technology, which may realize the execution of FP under continuous condition. Such simple microfluidics‐FP integrated approach has both methodological and practical value for the synthesis of functional materials. This paper mainly presents the synthesis and characterization of β‐cyclodextrin/poly(vinylimidazole‐co‐N‐vinylcaprolactam‐co‐acrylic acid) (β‐CD/P(VI‐co‐NVCL‐co‐AA)) copolymers by using thermal frontal polymerization (TFP). Hydrogels were found to be self‐healing with good mechanical performance and show dual thermo‐pH responsive behavior. Low‐cost, energy‐saving and efficient method of thermal frontal polymerization process was integrated with microfluidics technology to prepare supraball hydrogel. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1412–1423 [ABSTRACT FROM AUTHOR]

In this study, four fillers from forest‐based wastes were studied using thermogravimetry and contact angle measurements, and their compatibility with polyurethane were investigated by infrared spectroscopy performed in induced reaction mixtures, wherein the fillers were tested in the presence of excess isocyanate and catalyst. The fillers were then incorporated into rigid bio‐based polyurethane foams (RPUFs), which were characterized using thermal and combustion analyses. Wood presented higher compatibility with the polyurethane system, leading to a copolymer formation comprised by urethane groups during its polymerization. Filled RPUF reached increased thermal and dimensional stabilities, and similar thermal conductivities and flammabilities compared with the neat RPUF. POLYM. COMPOS., 39:E1770–E1777, 2018. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]