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• A molecular simulation method is developed to study nanoparticle composed of coarse-grained random copolymer model. • Molecular and surface properties of random copolymer nanoparticle are reported. • The anisotropic orientation at the level of bond and chain in nanoparticles are reported. Random copolymer nanoparticles were studied by Monte Carlo simulation of coarse-grained models on the high coordination lattice. Molecular and surface properties of free-standing nanoparticle were characterized at fixed 50% co-monomer content as a function of the interaction strength between co-monomer units. Intramolecular interaction for all copolymer chains were treated by the Rotational Isomeric State (RIS) model of polyethylene (PE). To simulate the copolymer model, the non-bonded interactions for comonomer units were described by different parameter sets of the Lennard-Jones energy. When the co-monomer interaction was stronger, the bulk densities of nanoparticles were increased and the interfacial widths were narrower. Near the surface, end beads of copolymer chains were segregated and the bond orientation was preferably perpendicular to the surface. Molecular shape and molecular size of copolymer chains were slightly changed as a function of co-monomer interaction strength and most of which occurs close to the surface. For chain orientation, the largest principal axis tended to orient parallelly to the surface, and then changed toward randomly isotropic orientation for weaker co-monomer interaction. The intrachain energies were decreased at the surface region implying more trans conformation while the non-bonded energies were increased due to better monomer packing at the surface region. The change of system energetics was more apparent as a function of the co-monomer interaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of three random and one block 6FDA-DAM based copolyimides with various selectivity enhancing moieties. • Fine-tune H 2 S/CH 4 selectivity of polyimides with improved sour mixed-gas separation properties. • Quinary sour mixed-gas permeation properties at elevated feed pressures. Natural gas purification is a challenging task due to the existing number of contaminants in the mixture. Sour natural gas, in particular, presents an even higher challenge due to the presence of the highly toxic hydrogen sulfide (H 2 S) gas. These contaminants level must be reduced to meet the sales gas specifications. In this paper, three DAM-based random copolymers were prepared for simultaneous improvement of the acid gases (CO 2 and H 2 S) separation properties of their corresponding membranes. While the developed membranes exhibit high CO 2 /CH 4 selectivity in a non-sour mixed-gas, their unconventional behavior during sour gas separation is difficult to predict. Therefore, their membranes were subjected to sour mixed-gas separation tests a quinary gas mixture including 20 vol% H 2 S at different upstream pressures up to 34.5 bar. Each membrane demonstrated one or more improved properties in terms of acid gases permeability and selectivity coefficients. Taking into consideration the overall performance, membranes prepared from 6FDA-DAM/6FpDA (1:3) exhibited the most attractive separation properties among the series prepared. However, based on the relatively high H 2 S/CH 4 selectivity obtained of 6FDA-DAM/CARDO (1:3) membranes, a block 6FDA-DAM/6FDA-CARDO (1:1) copolyimide was prepared, and the sour mixed-gas separation properties were evaluated. The overall block copolymer membrane demonstrated very attractive productivity and efficiency, compared to the standard industrially used glassy polymer, cellulose acetate, thereby rendering it a potential candidate for sour natural gas purification. [ABSTRACT FROM AUTHOR]

Graft (from linear homopolymers) and random (from a linear random copolymer) copolymer microgels of diallyldimethylammonium chloride (DADMAC) and acrylamide were synthesized via a free-radical mechanism using a γ-radiation technique. These copolymer microgels were evaluated as flocculants on a model dilute TiO2 colloid suspension using a turbidimeter and a disc centrifuge photosedimentometer, and their performances were compared with the linear homopolymers and their blends. It was found that microgels produced after an appropriate irradiation time showed improved flocculation behavior over their nonirradiated linear counterparts. The graft microgels performed better than the corresponding random microgels. For a γ-radiation dosage of 100 krad/h, the graft microgels obtained by irradiating a 30% DADMAC (by weight) homopolymer blend for 3 h showed the maximum reduction in the relative turbidity of the TiO2 suspension as well as the largest fraction of larger particles flocculated. [ABSTRACT FROM AUTHOR]

Analytical expressions for the meridional scattering from highly oriented random copolyesters are presented. These procedures are utilised in developing the relationship of the features in the diffraction pattern to compositions and relative lengths of the constituent monomer units. The difference between the scattering patterns for random and block copolymers are discussed. The theory is applied to an example of a liquid crystal froming random copolyester. [ABSTRACT FROM AUTHOR]

The aging behavior of a series of polypropylene random copolymer (PP-RCP) reactor powder samples was studied by NMR relaxometry, a.k.a. Industrial Magnetic Resonance (IMR). The samples, which had been stored for two years since polymerization, were heated for 20 min at 120 °C to mimic the morphology of freshly polymerized samples, then cooled down and stored at ambient temperature for one month during which NMR experiments were conducted to observe the morphological changes. Sixteen PP-RCP samples with a wide range of compositions were found to follow a rather consistent trend. For most samples, crystallinity increased during aging, at the expense of the amorphous population, while the interfacial population remained mostly unchanged. In the meantime, the segmental mobility of the interfacial phase steadily decreased. A strong correlation was found between the population of the amorphous component and the T 2 relaxation time of the interfacial component, the precise mechanism of which is unknown. The likely mechanism of the morphological change during ambient temperature aging is secondary crystallization of the γ form on the lateral surface of the scaffold crystallites. [Display omitted] • Aging of PP random copolymers with a broad range of XS was studied by TD-NMR. • Subtle changes in the populations and dynamics of three phases could be detected. • Crystallinity increased and interfacial components became more rigid. • Observations support secondary crystallization on scaffold crystallite surface. [ABSTRACT FROM AUTHOR]

[Display omitted] • The design and synthesis of random donor-acceptor n-type conjugated polymers. • Understanding the effect of fluorination on relevant polymers. • Wide bandgap all-polymer solar cells with high efficiency of 9.04%. A series of random donor-acceptor conjugated polymers with naphthalene diimide and thiophene units were designed and synthesized with varying difluorothiophene (FTh) substitution. In comparison with the non-fluorinated polymer F0, FTh-containing random polymers exhibit increased molecular interaction in solution state as well as enhanced solid state ordering. However, higher FTh content leads to unfavorable decrease in polymer solubility. When incorporated into all-polymer solar cells (all-PSCs) using PT8 as the donor, the crystallinity between donor and acceptor polymer was optimized using random copolymer strategy, and a best PCE of 9.04% was achieved with 10% FTh substitution, which is among the highest reports of wide bandgap all-PSCs. We believe that these findings will further provide insight into the control of polymer-polymer blend with desirable optoelectronic properties. [ABSTRACT FROM AUTHOR]

• Double emulsion technique was used to entrap n-Eicosane in amphiphilic polymer. • Synthesize porous microcapsules possessing around 160 J/g latent heat. • >95% encapsulation efficiency of n-Eicosan and 95% thermal energy storage capacity. • Water dispersible, leak proof, highly durable and thermoregulation characteristics. • Potential application area includes wall materials in energy saving buildings. A facile fabrication technique of producing novel porous microcapsules encapsulating n-Eicosane as phase change material (PCM) with a random copolymer of poly (methyl methacrylate 0.9 - co -2-hydroxyethyl methacrylate 0.1) (poly(MMA 0.9 - co -HEMA 0.1)) as shell material is being reported. The porous microparticles (particle size: 31.8 ± 9 µm; porosity: ~30 ± 13%) with a hollow core (shell thickness: 1.60 ± 0.2 µm) were obtained by adopting a synthetic pathway of hot water assisted double emulsion (water/oil/water) system. Strikingly, the microcapsule system was found to entrap > 95% n-Eicosane, thus achieving significantly high thermal energy storage capability (~95%). The porous microcapsules with a phase transition enthalpy of ~ 160 J/g exhibited high phase transfer repeatability and long durability. The non-isothermal and isothermal DSC study further revealed the heat charging and discharging conditions for the microcapsules. Moreover, in contrast to neat hydrophobic PCM, the porous particles with partially hydrophilic shell (owing to polyHEMA unit) displayed better water dispersibility along with efficient thermal management characteristic as revealed by Infrared thermography. Thus, the microencapsulated phase change material in porous microcapsules can be a smart combination of good thermal energy storage function with wettability. Potentially such microcapsules may be exploited as thermal energy storage materials for space conditioning in buildings because of the suitable phase transition temperature (37 °C) displayed by the selected PCM (n-Eicosane). Our study comprehensively demonstrated water dispersible porous polymeric particles with significantly high thermal energy storage (>95%) performance that was not reported till date. [ABSTRACT FROM AUTHOR]

• Random copolymer (GN-ran-PO) was synthesized by ROP polymerization. • The compound was characterized by the FTIR, 1H- and 13CNMR, GPC and DSC spectra. • Improvement the mechanical properties of PGN based polyurethane network. • The investigation of the compatibility of copolymer-plasticizers systems. • Investigating of the mechanical properties of the polyurethane/plasticizer In this research, arandom copolymer of propylene oxide and glycidyl nitrate (poly [GN-ran-PO]) (Mn = 1152 g.mol−1) was synthesized via ring-opening polymerization of epoxides in the presence of boron trifluoride etherate (BF 3.OEt 2) as the catalyst. This copolymer has a potential use as a binder in the propellant industries. The obtained product has characterized by 1H and 13C NMR spectroscopy, FTIR, and gel permeation chromatography (GPC). The thermal behavior of the random copolymer was determined by differential scanning calorimetry (DSC). Energetic polyurethane was synthesized by curing of the random copolymer with different curing agents such as toluene-2,4-diisocyanate(TDI), isophorone diisocyanate(IPDI), desmodurN100, (IPDI/N100) and different NCO/OH ratios. To evaluate the plasticizing effect of the different plasticizers on the thermo-mechanical properties of the polyurethane, the compatibility of the copolymer with three energetic plasticizersincludingn‐butyl nitroxyethyl nitramine (BuNENA), trimethylol ethane trinitrate (TMETN), and 1,2,4-butanetriol trinitrate (BTTN) has studied using the solubility parameter, rheological and thermal analysis. The solubility parameter differences indicate that the BuNENA has better miscibility with this copolymer than others. This plasticizer reduced the glass transition temperature of its composition with copolymer from -47 °C to -58 °C. Moreover, the rheological analysis also confirms that BuNENA is more compatible with the copolymer. The mechanical properties effect of the BuNENA plasticizer on the polyurethane network has investigated using dynamic mechanical analysis (DMA) as well as the tensile test. The IPDI/N100 curing agents-polyurethane mixture, demonstrate appropriate mechanical properties (0.6 MPa stress and 109% elongation) that make it a suitable binder system comparison with pure PGN (unstable and de-cured). Also, the mechanical properties of the prepared polyurethane containing 20 wt.% BuNENA showed 0.42 MPa stress and 124% elongation. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Abstract: PPV random derivates were synthesized and characterized. Polymer light emitting diodes (PLEDs) were assembled using the random copolymers as emissive layer and showed EL in the blue-green region in function of the method of preparation. The increase in the average conjugation degree in the polymer chain led to the reduction of the turn-on voltage of the device. The addition of Alq3 as ETL increased tenfold the luminescence efficiency. [Copyright &y& Elsevier]

A set of teroligodepsipeptides with different compositions and di-hydroxy end groups has been synthesized by ring-opening copolymerization. These teroligodepsipeptides are promising matrix biomaterials to construct controlled drug release systems or telechelic building blocks for the synthesis of nanocarrier forming macromolecules. • A set of teroligomers from morpholine-2,5-diones (ter-ODPs) with one disulfide group was prepared and characterized. • A tin(IV) alkoxide from dibutyl tin(II) oxide and 2-hydroxyethyl disulfide served as catalyst/initiator system. • The ter-ODPs provided two terminal hydroxy groups. Oligodepsipeptides (ODPs) attract increasing attention as degradable materials in controlled drug delivery or as building blocks for nano-carriers. Their strong intermolecular interactions provide high stability. Tailoring the side groups of the amino acid repeating units to achieve a strong affinity to particular drugs allows a high drug-loading capacity. Here we describe synthesis and characterization of dihydroxy terminated teroligodepsipeptides (ter-ODPs) by ring-opening copolymerization (ROP) of three different morpholine-2,5-diones (MDs) in bulk in order to provide a set of teroligomers with structural variation for drug release or transfection. Ter-ODPs with equivalent co-monomer feed ratios were prepared as well as ter-ODPs, in which the co-monomer feed ratio was varied between 9 mol% and 78 mol%. Ter-ODPs were synthesized by ROP using 1,1,10,10-tetra- n -butyl-1,10-distanna-2,9,11,18-tetraoxa-5,6,14,15-tetrasulfur-cyclodecane (tin(IV) alkoxide) that was obtained by the reaction of dibutyl tin(II) oxide with 2-hydroxyethyl disulfide. The number average molecular weight (M n) of ter-ODPs, determined by 1H NMR and gel permeation chromatography (GPC), ranged between 4000 g·mol−1 and 8600 g·mol−1. Co-monomer compositions in ter-ODPs could be controlled by changing the feed ratio of co-monomers as observed by 1H NMR spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The amount of remaining monomers as determined by 1H NMR could be kept below 1 wt%. Macrocycles as main sources of byproducts as determined from MALDI-TOF-MS measurements were significantly lower as compared to polymerization by Sn(Oct) 2. Glass-transition temperature (T g) of ter-ODPs ranged between 59 °C and 70 °C. [ABSTRACT FROM AUTHOR]

Structural relaxation in polymers occurs at temperatures in the glass transition range and below. At these temperatures, crystallization is controlled by diffusion and nucleation. A sequential occurrence of structural relaxation, nucleation, and crystallization was observed for several homopolymers during annealing in the range of the glass transition. It is known from the literature that all of these processes are strongly influenced by geometrical confinements. The focus of our work is copolymers, in which the confinements are caused by the random sequence of monomer units in the polymer chain. We characterize the influence of these confinements on structure formation and relaxation in the vicinity of the glass transition. The measurements were performed with a hydrogenated nitrile-butadiene copolymer (HNBR). The kinetics of the structural relaxation and the crystallization was measured using fast differential scanning calorimetry (FDSC). This technique was selected because of the high sensitivity, the fast cooling rates, and the high time resolution. Crystallization in HNBR causes a segregation of non-crystallizable segments in the macromolecule. This yields a reduction in mobility in the vicinity of the formed crystals and as a consequence an increased amount of so-called "rigid amorphous fraction" (RAF). The RAF can be interpreted as self-assembled confinements, which limit and control the crystallization. An analysis of the crystallization and the relaxation shows that the kinetic of both is identical. This means that the Kohlrausch exponent of relaxation and the Avrami exponent of crystallization are identical. Therefore, the crystallization is not controlled by nucleation but by diffusion and is terminated by the formation of RAF. [ABSTRACT FROM AUTHOR]

Stimuli-responsive polymers have attracted significant interest in the fields of advanced materials and biomaterials. Herein, temperature- and pH-responsive glycopolymers, which are composed of N-isopropylacrylamide, methacrylic acid, and an acrylamide derivative bearing a lactose moiety, were synthesized via radical copolymerization. The series of resulting glycopolymers had different degrees of substitution of the lactose moieties, were responsive to temperatures between 26.6 °C and 47.6 °C, and formed aggregates above the lower critical solution temperature limit in mild acidic aqueous media (pH 4–6). The temperature-responsive behavior was dependent on the prevailing pH conditions, as no aggregation was observed in neutral and basic aqueous media (pH > 7). The aggregates had saccharide moieties on the surface in aqueous media. The number of saccharide moieties on the surface depended on the saccharide-containing unit ratio in the glycopolymer. The ratio was determined via enzymatic hydrolysis of the lactose moieties using β-galactosidase and the subsequent detection of the released galactose. [ABSTRACT FROM AUTHOR]

Continuous breakthroughs have been achieved in improving the efficiency of all-polymer solar cells (all-PSCs) using diimide-based polymer acceptors, and their easy-to-synthesize, low-cost, and high stability attributes make them potential candidates for use in commercial all-PSCs. However, their low light absorption coefficient, strong aggregation, and poor adaptability with high-efficient polymer donors still limit further improvements in the device performance. Here, we combine the advantages of fluorinated bithiophene and rhodanine dye molecules to create low-cost diimide-based polymer acceptors, PNDI-2FT-TR10 and PNDI-2FT-TR20, by random copolymerization for achieving highly efficient and stable all-PSCs. The synergistic effects of fluorine atoms and rhodanine dye molecules not only significantly improve the absorption coefficient but also enable enhanced miscibility and stability of the blend film. When blended with a PM6 donor, the PNDI-2FT-TR10-based device exhibits a notable power conversion efficiency (PCE) of 10.71% with a short-circuit current ( J SC ) of 17.32 mA cm -2 show outstanding values for diimide-based all-PSCs, and this is the first report on blending diimide-based polymer acceptors with the PM6 donor to achieve high-performance all-PSCs. Moreover, the favorable morphology of the active layer enables the device to have good thickness tolerance and thermal stability. The results demonstrate that the absorption coefficients, blend morphology, and photovoltaic properties of all-PSCs could be rationally optimized by a random copolymer.J SC show outstanding values for diimide-based all-PSCs, and this is the first report on blending diimide-based polymer acceptors with the PM6 donor to achieve high-performance all-PSCs. Moreover, the favorable morphology of the active layer enables the device to have good thickness tolerance and thermal stability. The results demonstrate that the absorption coefficients, blend morphology, and photovoltaic properties of all-PSCs could be rationally optimized by a random copolymer.