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Herein, we designed and synthesized a thermally stable carboxybetaine copolymer with a one- or three-carbon spacer between ammonium and carboxylate groups (CBMA1 and CBMA3) to create an anti-nonspecific adsorption surface with the ability to immobilize antibodies.

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Inherent interaction of the urea group on the coating surface for biomaterials application.

The study utilized machine learning to predict highly accurate polymer properties, mainly when quantum chemical calculation values were included as variables, thus suggesting a promising tool for accelerating polymer development with new monomers.

The aim of this study is to validate an in vitro skin irritation test (SIT) using three-dimensional reconstructed human epidermal (RhE) skin equivalents prepared by layer-by-layer (LbL) method (LbL-3D Skin) in a series of inter-laboratory studies. The goal of these validation studies is to evaluate the ability of this in vitro test to reliably discriminate skin irritant from non-irritant chemicals, as defined by OECD and UN GHS. This me-too validation study is to assess the within- and between-laboratory reproducibility, as well as the predictive capacity, of the LbL-3D Skin SIT in accordance with performance standards for OECD TG 439. The developed skin model, LbL-3D Skin had a highly differentiated epidermis and dermis, similar to the Validated Reference Methods (VRM) and native human skin. The quality parameters (cell survival in controls, tissue integrity and barrier function) were similar to VRM and in accordance with OECD TG 439. The LbL-3D Skin SIT validation study was performed by three participating laboratories, and consisted of three independent tests using 20 reference chemicals. The results obtained with the LbL-3D Skin demonstrated high within-laboratory and between-laboratory reproducibility, as well as high accuracy for use as a stand-alone assay to distinguish skin irritants from non-irritants. The predictive potency of LbL-3D Skin SIT using total 54 test chemicals were comparable to those in other RhE models in OECD TG 439. The validation study demonstrated that LbL-3D Skin has proven to be a robust and reliable method for predicting skin irritation.

Polylactide (PLA) stereocomplexes (SCs) formed by poly(L,L-lactide) (PLLA) and poly(D,D-lactide) (PDLA) are well known, and their derivatives and copolymers have also been reported. However, little research has been conducted on SCs with a combination of one enantiomer of a copolymer and a homopolymer. In this study, we selected a PLA copolymer with poly(ethylene glycol) (PEG) and a urethane capping PLA bearing almost the same molecular weights as PLA segments and prepared various SC samples. Depending on the combination of L-isomers and D-isomers, the SCs were classified as a Homo-SC, Co-SC, and Multi-SC: the Homo-SC had the same polymer chain ends and copolymers, the Co-SC had different polymer chain ends and copolymers, and the Multi-SC had a mixture of various polymer chain ends and copolymers. Depending on the chain end structures, the melting points of the SCs changed in the case of Homo-SC and Co-SC, but Multi-SC showed two broad melting points at ~200 °C. We propose that these findings are the results of the various combinations of polymer–polymer interactions in the case of Multi-SC. We selected a polylactide (PLA) copolymer with poly(ethylene glycol) (PEG) and a urethane capping PLA and prepared various stereocomplex (SC). Depending on the combination of L-isomers and D-isomers, the SCs were classified as Homo-SC, Co-SC, and Multi-SC: Homo-SC by the same polymer chain ends and copolymers, Co-SC by different polymer chain ends and copolymers, and Multi-SC by a mixture of various polymer chain ends and copolymers. Multi-SC showed two broad melting points at around 200 °C, suggesting the various combinations of polymer–polymer interaction in the case of Multi-SC.

Poly(ethylene terephthalate) (PET) is a widely used plastic in bottles and fibers; its waste products pollute the environment owing to its remarkable durability. Recently, Ideonella sakaiensis 201-F6 was isolated as a unique bacterium that can degrade and assimilate PET, thus paving the way for the bioremediation and bioconversion of PET waste. We found that this strain harbors a poly(hydroxyalkanoate) (PHA) synthesis gene cluster, which is highly homologous with that of Cupriavidus necator, an efficient PHA producer. Cells grown on PET accumulated intracellular PHA at high levels. Collectively, our findings in this study demonstrate that I. sakaiensis can mediate the direct conversion of non-biodegradable PET into environment-friendly plastic, providing a new approach for PET recycling.

The ABA-type triblock-copolymers (BCPs) of polylactide (PLA) and poly(ethylene glycol) (PEG) were synthesized as axle components for rotaxane formation. It is known that α-cyclodextrin (CD) exists near the PEG moiety in pseudo-polyrotaxane (PPRX), and the PLA moiety can form a stereocomplex (SC), by mixing with L- and D-isomers. In this study, various CDs, including β-CD and γ-CD, were used as wheel components, and effects of CD structures on both PPRX and SC formations were studied. The solubility of CDs is influenced to form the PPRX, resulting in differing numbers of CDs in the axle. PPRX structures were investigated by

Photo-iniferter reversible addition-fragmentation chain transfer (PI-RAFT) of N-vinylformamide (NVF) was demonstrated by using purple light. PNVFs with predetermined molar masses and narrow molar mass distributions were obtained. High RAFT chain-end fidelity was confirmed by MALDI-TOF and ESI-MS, and chain extension experiment. To demonstrate the potential of this approach, an original PVP-b-PNVF diblock copolymer was synthesized and characterized by aqueous SEC, A4F, and

Polyvinylamine-based double hydrophilic block copolymers are synthesised from RAFT polymerisation of N-vinylformamide.

Of the various synthetic biodegradable polymers, polylactide, poly(butylene succinate), and poly(hydroxyalkanoate) have been widely studied and developed. This review focuses on studies of the chai...

Poly(N-vinylamide) derivatives were synthesized to improve the performance of kinetic hydrate inhibitors (KHIs). In this work, we synthesized poly(N-vinylformamide) (PNVF) and poly(N-vinylcaprolactam) (PVCap) by free radical polymerization with several commercial chain transfer agents (CTAs), which afforded a few thousand Mn. The structures of synthesized PNVF and PVCap were then investigated by 1H NMR and MALDI-TOF/MS spectrograms. KHI properties of the synthesized PNVF and PVCap polymers were also evaluated by the high-pressure slow constant cooling KHI test method. Some of the tested polymers showed a better KHI effect than PVCap.

To modify the flexibility of chitosan (CS), poly(trimethylene carbonate) (PTMC) and its derivatives and copolymers were blended with a chitosan derivative, N,N,N-trimethylchitosan (TM-CS). The tensile strength of the CS and TM-CS films blended with PTMC was found to cause brittleness, but a PTMC derivative copolymer bearing carboxylic acid improved the elongation properties of TM-CS. A softer film was obtained for a blend film composed of TM-CS with 25% consisting of an added PTMC derivative copolymer bearing a 10% carboxylic acid moiety on the side chain. This film showed an elongation at break of 20.6 ± 9.3% with a tensile strength of 2.2 ± 0.83 MPa, while the original CS and TM-CS films showed an elongation at break of 7.4 ± 3.4% and 9.2 ± 1.6% with a tensile strength of 13.6 ± 1.0 MPa and 3.7 ± 0.35 MPa, respectively. This is the first report of the modification of CS using polymers with a PTMC backbone. Poly(trimethylene carbonate) (PTMC) based polymers were blended with N,N,N-trimethylchitosan (TM-CS). The tensile strength of the chitosan (CS) and TM-CS films blended with PTMC was found to cause brittleness, but a PTMC derivative copolymer bearing carboxylic acid improved the elongation properties of TM-CS. A softer film was obtained for a blend film composed of TM-CS with 25% consisting of an added PTMC derivative copolymer bearing a 10% carboxylic acid moiety on the side chain. This is the first report of the modification of CS using polymers with a PTMC backbone.

The radical copolymerization on α-substituted fluoroalkyl acrylate (FA) monomer bearing C4, C6, and C8 as perfluoroalkyl (Rf) groups, as well as the variation of α-substituents, hydrogen, methyl, and chlorine with styrene was investigated. Q-e values and monomer reactivity ratio of FA monomers were estimated. When the alpha position of FA monomer of C6 as Rf group was changed from −H to −CH3, the e value decreased from 0.85 to 0.60. The substituent of −Cl resulted in an e value of 1.06. The Q values were also markedly changed. When the alpha position was changed from −H to −CH3, the Q value increased from 0.38 to 0.79. The substituent of −Cl resulted in a Q value of 2.90. The copolymer composition of α-substituted FA monomers with stearyl acrylate (C18A) was simulated. The obtained results revealed that a chlorine substituent at the alpha position emphasizes the polymerization which would contribute to a novel material design containing a fluorine side chain in a monomer structure.

We designed and synthesized a topological isomer with comb and linear polyurethanes (PUs), bearing one, two, and three units of oligo(ethylene glycol) (OEG) at the side chain. Surprisingly, comb PUs with OEG side chain lengths of two and three units showed about twice as much stress at the break as those of the corresponding linear isomers. The analysis of rheological and structural parameters revealed that the comb PU in this study was more suitable for maintaining entanglement concerning the side chain length than that of the conventional comb polymer. Since the comb PU showed high zero shear viscosity like the conventional comb polymer, it was found that there is molecular chain friction due to the side chain. Therefore, it is assumed that both the entanglement compatibility and the molecular chain friction resulted in an enhancement of the mechanical strength, which was achieved by the topological isomer.

Kinetic hydrate inhibitors (KHIs) are polymers used in a chemical method to prevent gas hydrate plugging of oil and gas production flow lines. The main ingredient in a KHI formulation is one or more water-soluble amphiphilic polymers. Several classes of KHI polymers contain pendant heterocyclic 5-rings including poly(N-vinylpyrrolidone) (PVP) and poly(2-isopropenyl-2-oxazoline) (PiPOx). Here, we present a KHI performance study on polymers based on the 5-ring vinylic monomer 5-methyl-3-vinyl-2-oxazolidinone (VMOX), which has only recently been manufactured in large quantities. Low molecular weight PVMOX homopolymers were produced in quantitative yield using radical polymerization, with or without a chain transfer agent. For example, PVMOX-2.4k (Mn = 2400 g/mol) had a cloud point at 2500 ppm of 73 °C in deionized water. The polymers were screened for KHI performance using slow constant cooling tests (1.0 °C/h) in high-pressure rocking cells with a synthetic natural gas blend. At 2500 ppm, PVMOX-2.4k gave a better performance than PVP or PiPOx at a similar molecular weight but not as good as poly(N-vinylcaprolactam) (PVCap). Isobutyl glycol ether was shown to enhance the KHI performance of PVMOX. PVMOX gave improved performance with increasing concentration but not as steep of an improvement as some of the best amide-based KHI polymers. A 1:1 copolymer of VMOX with N-vinylcaprolactam gave improved performance compared to the PVMOX homopolymer.

The deployment of kinetic hydrate inhibitors (KHIs) is a chemical method for the prevention of gas hydrate plugging in gas, condensate, and oil production flow lines. Polymers made using the monomer N-vinylcaprolactam (VCap) are one of the most common KHI classes. Alternative classes of polymers containing caprolactam groups are rare. Here, we present a study on oxyvinylenelactam polymers and copolymers with pendant piperidone or caprolactam groups. Low-molecular-weight homo- and copolymers were obtained. The nonrotating vinylene groups impart rigidity to the polymer backbone. Poly(oxyvinylenecaprolactam) (POVCap) was insoluble in water, but poly(oxyvinylenepiperidone) (POVPip) and OVPip:OVCap copolymers with 60+ mol % OVPip were soluble with low cloud points. KHI screening tests were carried out using the slow constant cooling method in steel rocking cells. POVPip was water soluble with no cloud point up to 95 °C but showed a poor KHI performance. In contrast, OVPip:OVCap copolymers with about 60–70 mol % OVPip were also water soluble and showed a reasonable KHI performance, better than that of poly(N-vinylpyrrolidone) but not as good as that of poly(N-vinylcaprolactam). Surprisingly, several additives known to be good synergists for VCap-based polymers showed negligible synergy or were antagonistic with the 62:38 OVPip:OVCap copolymer with regard to lowering the onset temperature of hydrate formation. However, a blend with hexabutylguanidinium chloride showed a strong effect to delay the onset of rapid hydrate formation.

Kinetic hydrate inhibitor (KHI) polymers have been used for over 25 years to prevent gas hydrate formation in oil and gas production flow lines. KHI polymers are water-soluble at hydrate formation ...

Stimuli-responsive materials have been actively researched over the past few decades. Among such materials, spiropyran is one of the most attractive compounds because the structure and polarity of the material are dramatically changed after photo irradiation, unlike other materials. In this work, we designed and synthesized a spiropyran derivative (SpMA) with a methacryloyl group on the nitrobenzene ring of a spiropyran skeleton. The UV spectra of the newly synthesized SpMA showed the photo-isomerization of spiropyran. The maximum absorption wavelength (λmax) of SpMA was 616 nm in n-hexane, a nonpolar solvent, although λmax of SpMA was 532 nm in methanol, a polar protic solvent, which resulted in an 84 nm blue-shift. SpMA was successfully polymerized by ruthenium (Ru)-catalyzed living radical polymerization. Poly(SpMA) (PSpMA) was then spin-coated on a PET substrate in order to control the surface properties of water repellency and cell adhesion. The water repellency was decreased approximately 10° under UV irradiation, because of the polarity change of PSpMA caused by photo-isomerization from the spiropyran (SP) type to the merocyanine (MC) type. In addition, NIH3T3 cells were spread only on 6% of the surface of the PSpMA thin film after UV irradiation compared with no UV irradiation. The polarity change of PSpMA by photo-isomerization is also believed to be the reason for this behavior. As a result, we successfully synthesized a photo-controllable cell culture scaffold.

Three crosslinked films with different ratios of hydrophilic and hydrophobic monomers were prepared using trimethylene carbonate backbone with ester free structure. Oligo(ethylene glycol) (OEG) was...

This study describes the long-distance diastereomeric effect on thermoresponsive properties in water-soluble diastereomeric polyurethanes (PUs) composed of an L-lysine ethyl ester diisocyanate and a trimethylene glycol L-/D-tartrate ester, which have differences in spatial arrangements of the ethyl esters in the mirror image. The PUs based on L-lysine and L-/D-tartrate ester, named L-PU and D-PU, were synthesized with various number average molecular weights from 4700 to 13 100. In turbidimetry, L-PU showed a steep phase transition from 100%T to 0%T within about 10 °C at 4 g L−1, whereas D-PU did not change completely to 0%T transmittance even at 80 °C at 4 g L−1. In addition, the thermoresponsive properties of L-PU were less affected by concentration than those of D-PU. This long-distance diastereomeric effect on thermoresponsive behavior between L-PU and D-PU appeared in common among 6 samples with 4700 to 13 100 number average molecular weight. In the dynamic light scattering experiments at each transmittance, the hydrodynamic diameter (Dh) of l-PU increased up to 1000 nm, while the Dh of D-PU remained almost at 200–300 nm. The CO stretching vibration of FT-IR spectra showed that D-PU has more hydrogen-bonded ester groups than L-PU. Thus, we speculated that the difference in the retention of polymer chains in the micelle to promote intermicellar bridging generates the long-distance diastereomeric effect.

Encapsulated paraffin-type phase change materials are considered important candidates for thermal energy storage applications. In this paper, we present icosane coated in a layer-by-layer fashion using the weak polyelectrolytes poly(acrylic acid) and poly(allylamine) in order to create ultra-thin cross-linkable and robust polymer encapsulations with storage capacities close to the pristine icosane. After coating, SEM images displayed an average particle size between 20 and 50 µm. Generally, smooth surface structures of the coated particles compared to uncoated icosane-surfactant particles, 1H NMR and FT-IR spectra as well as fluorescence imaging confirmed the successful encapsulation. Calculations of the PCM content revealed that the final product consisted of 88.6% core material. Accordingly, the resulting PCM capsules showed high storage capacities of 199.1 J g−1 close to the original value of pristine icosane (223.6 J g−1). Thermal stability was confirmed by TGA, revealing an increased resistance to thermal degradation of the coated particles (T10, bulk = 175.7 °C and T10, capsule = 186.8 °C). Moreover, repeatability and reliability of the phase change behavior were confirmed in thermal cycling experiments including 100 heating-cooling cycles with no observable influence on the performance of our material.

Ester free poly(trimethylene carbonate) (PTMC) derivatives show biocompatibility and biodegradability and do not generate any acidic compounds after decomposition. Their syntheses methods are limited however, hampering their material application. Herein, we established a novel synthesis route of ester free trimethylene carbonate (TMC) derivatives. The novel synthesis route was described using six aldehydes and one ketone as starting compounds. The key reaction is the selective deprotection from two protected hydroxyl groups in the cyclic acetal structure by diisobutylaluminium hydride. This novel synthesis route means that it is possible to convert aldehyde group to ether groups in the side chain of TMC. Conventionally, only a substituent derived from a primary alcohol was introduced into the side chain. We therefore succeeded in decreasing the number of reaction steps from five to three, compared with the conventional route. Furthermore, the development of a novel synthesis route enabled the introduction of substituents derived from secondary alcohols, anticipating the creation of further types of ester free TMC derivatives.

In regards to the addition of functionality into polylactide, the chemical modification method is a promising approach. Herein, we selected 5-hydroxymethylfurfural (HMF) as the initiator to introduce the chain end of polylactide. HMF is a valuable biomass produced from glucose–fructose via dehydration. The structure of HMF contains aldehyde and alkyl alcohol, which resembles benzyl alcohol. This polymer was able to control the molecular weight. This meant that the polymerization initiated from HMF showed effective initiation for the polymerization, compared with vanillin in previous research. The present polymer improved the thermal properties by stereocomplex formation with both enantiomeric homopolymers. Subsequently, the terminal group of aldehyde of HMF undergoes bonding/removing as a dynamic formation with hydrophilic amine under equilibrium conditions. This phenomenon self-assembled interesting nanostructured morphology, and also, it was able to form a self-assembled monolayer (SAM). By using this S...

Thermosensitive poly(N-vinylamide) derivatives bearing an oligo ethylene glycol (OEG) chain at the N-position were designed for development of a kinetic hydrate inhibitor (KHI). Novel N-vinylamide monomers bearing an OEG chain at the N-position were synthesized and copolymerized with N-vinylformamide (NVF) or methyl N-vinylacetamide (MNVA) by free radical polymerization. Then, thermosensitive behaviors, such as lower critical solution temperature (LCST), of the synthesized poly(N-vinylamide) derivatives were investigated by light transmittance and DSC measurement. The LCST values were observed over a wide temperature range from 45 to 90 °C due to the ethoxy OEG chain at the N-position. Their phase transition properties were investigated under dilute condition by light scattering measurement. Furthermore, KHI values of the synthesized polymers were evaluated by the THF hydrate crystal growth method. On the basis of these results, it is expected that the polymers of synthesized poly(N-vinylamide) derivative...

Novel poly(e-caprolactone) (PCL)–glycerol polyester was synthesized in one step in the presence of Novozym 435 under mild reaction conditions. The objective of the study was to investigate the feasibility of enhancing the hydrophilicity of PCL by condensing it with glycerol through biocatalytic approach. Effect of reaction time, glycerol-to-CL ratio and CL-to-toluene ratio was studied. The 1H NMR and GPC results established that self-condensation of CL units and condensation of CL with glycerol units take place simultaneously. When the glycerol content was 10 and 20 mol% with regard to CL, condensation continued for 6 h; further extension of reaction time resulted in the cleavage of ester linkages. When the glycerol content was increased to 40 mol%, the condensation of CL–glycerol units was accomplished in 4 h; however, the reaction had to get extended beyond 6 h for complete condensation of CL–CL units. The study revealed that the crystallinity and the melting temperature (Tm) of the products altered with an increase in the glycerol content. Furthermore, TGA and contact angle values of water on PCL and its glycerol derivative films revealed that the water uptake capacity of PCL too increased significantly with the increase in glycerol content, rendering PCL more hydrophilic.

The organogels poly(styrene-co-divinylbenzene), PS gel (1); poly(styrene-co-divinylbenzene-co-vinylpyridine), PS-VP gel (2); poly(styrene-co-divinylbenzene-co-vinylbenzoic acid), PS-VBA gel (3); and poly(styrene-co-divinylbenzene-co-styrenesulfonate), PS-SS gel (4) were prepared with limonene by varying the concentration of cross-linker and comonomer to control the properties of the gels. Limonene was used as the swelling solvent due to its low toxicity and environmental friendliness. Additionally, 4-vinylpyridine (VP), 4-vinylbenzoic acid, and 4-styrenesulfonate were introduced as cationic and anionic moieties to act as interaction units. An increase in the divinylbenzene ratio improved the mechanical strength, as evidenced by an increase in the G′ value; for example, the G′ of gel 3 improved from 15,000 Pa with 5% cross-linking to 93,000 Pa with 10% cross-linking. However, the increased cross-linking reduced the solubility in limonene, resulting in a decrease in the swelling ratio from 1.5 to 0.7. Cationic gel 2 can adsorb anionic compounds, while anionic gel 4 can adsorb cationic compounds. Gel 2 with 5 mol% VP was able to adsorb approximately 4.4 mg/g of an anionic dye, while gel 4 with 5 mol% SS was able to adsorb approximately 6.6 mg/g of a cationic dye. The limonene organogels were used for lipophilic drug storage and the controlled release of testosterone due to their dense polymer network.

Oilfield scale inhibitors have been used for many decades, mostly to fight carbonate and sulfate scaling. Many inhibitors are known, but only a few show good biodegradation to make them environmentally acceptable in areas with strict regulations, such as offshore Norway. Often high biodegradation is at the expense of other useful properties, such as thermal stability for high-temperature squeeze applications. We have now synthesized and investigated a new class of polycarbonate polymers with pendant anionic functional groups (carboxylate and phosphonate) as potential oilfield scale inhibitors. These polymers have a carbonate group in the backbone. Polymers with carboxylate and phosphonate side groups were prepared. We report here the scale inhibition performance of these polymers at 100 °C against both calcite and barite scaling at typical North Sea conditions in dynamic tube-blocking equipment, both before and after aging at 130 °C. The phosphonated copolymer gave very good performance against calcite sc...