Synthesis and Properties of Polymers Based on Styrene and α-angelicalactone

Influence of comonomer content and short branch length on the physical properties of metallocene propylene copolymers

The compatibilizing effect of styrene-co-4-vinylpyridine (SVP) random copolymers on the immiscible polystyrene (PS)–polyethylene-based ionomer (Surlyn) blends was examined by means of scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and tensile test. For the binary SVP–Surlyn and ternary PS–Surlyn–SVP blends, the domain size of dispersed phase decreases dramatically with the increase in the vinyl pyridine (VP) content of the SVP copolymers. The mechanical properties are improved with increasing the VP content in copolymers. FTIR results suggest that the compatibilization in this blend system is attributed to the ion–dipole interaction between the polar VP groups of SVP copolymer and ionic groups of Surlyn. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 807–816, 1998

The miscibility and phase behavior of ternary blends containing dimethylpolycarbonate (DMPC), tetramethylpolycarbonate (TMPC) and poly[styrene‐co‐(methyl methacrylate)] copolymer (SMMA) have been explored. Ternary blends containing polystyrene (PS) instead of SMMA were also examined. Blends of DMPC with SMMA copolymers (or PS) did not form miscible blends regardless of methyl methacrylate (MMA) content in copolymers. However, DMPC blends with SMMA (or PS) blends become miscible by adding TMPC. The miscible region of ternary blends is compared with the previously determined miscibility region of binary blends having the same chemical components and compositions. The region where the ternary blends are miscible is much narrower than that of binary blends. Based on lattice fluid theory, the observed phase behavior of ternary blends was analyzed. Even though the term representing the Gibbs free energy change of mixing for certain ternary blends had a negative value, blends were immiscible. It was revealed that a negative value of the Gibbs free energy change of mixing was not a sufficient condition for miscible ternary blends because of the asymmetry in the binary interactions involved in ternary blends. Copyright © 2004 Society of Chemical Industry

N-(2,4,5-trichlorophenyl) acrylamide (CPAM) monomer was synthesized and copolymerized with BA and MMA using varying concentration of CPAM monomer via seed batch emulsion polymerization technique. The resultant CPAM copolymers were characterized by FT-IR spectroscopy. Thermal behaviors of CPAM copolymers were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was observed that glass transition temperature and thermal stability of copolymers increases with increase in CPAM content in copolymers. Also the CPAM copolymers were subjected to evaluate Limiting Oxygen Index (LOI) and Mechanical properties. The LOI and mechanical properties results showed that as the CPAM concentration increases, its Limiting Oxygen Index and mechanical properties increases. The CPAM copolymers were used to screen their antibacterial activity against various microorganisms (E.Coli, S. Aureus, M. Luteus, and B. Subtilis.) and it was observed that its antibacterial activity has a direct influence on the CPAM concentration.

Herein we report the synthesis of new reactive stimuli-responsive polymers by RAFT copolymerization of glycidyl methacrylate and three cyclic N-vinyllactam derivatives. The copolymerization process was thoroughly investigated and the influence of the steric hindrance originating from the monomer structure of cyclic N-vinyllactams on the polymerization process and the properties of obtained copolymers were studied. A series of water-soluble copolymers with variable chemical composition, controlled molecular weight and narrow dispersity ( Đ) were synthesized and their properties are systematically investigated. Experimentally determined cloud points for different copolymers in aqueous solutions indicate shift of lower critical solution temperature (LCST) to lower values with the increase of GMA content in copolymers and increase of the lactam ring size. The obtained reactive stimuli-responsive copolymers can be efficiently used for encapsulation of cellulase in water-in-oil emulsions forming biohybrid nanogels. The enzymes entrapped in nanogels demonstrated significantly improved resistance against harsh store conditions, chaotropic agents, and organic solvents.

Structure and properties of new polyester elastomers composed of poly(trimethylene terephthalate) and poly(ethylene oxide)

Studies on properties of electrospinning nanofibers of biodegradable tercopolymers derived from ɛ-CL, TMC and LLA

Ethylene–co–norbornene copolymerization in the presence of a chain transfer agent

Synthesis, thermal and optical properties of crosslinked poly(isobornyl methacrylate-co-butyl acrylate) copolymer films

Copolymers of styrene (ST) and N-methylolacrylamide (NMA) were synthesized by emulsion polymerization for different initial weight ratios of ST/NMA. Fast reaction rates and high conversions are achieved regardless of the ST/NMA ratio. NMA content in copolymers, as deduced by DSC, FTIR and Kjeldhal analysis, is higher as the initial ST/NMA ratio decreases. Glass transition temperature of copolymers increases as the ST/NMA ratio decreases and it decreases with reaction time for a fixed ST/NMA ratio. The latter results and FTIR spectra as well as Kjeldhal analysis as a function of reaction time indicate that NMA reacts initially in the aqueous phase, after which ST, because of its overall larger concentration, is incorporated preferentially in the polymer.

Formation of charge‐transfer complexes with trinitrotoluene (TNT) as a common acceptor was studied in detail by using dimethyltoluidine (DMT), poly‐N‐dimethyl‐p‐aminostyrene (poly‐ASt), and also copolymers of aminostyrene (ASt) and styrene (St) as donors. A smooth bathochromic shift in λmax was observed with increasing ASt unit content in copolymers. Values of the constant for charge transfer complex formation KCT were found to increase smoothly with ASt unit content. However, the KCT value with DMT did not coincide with the value extrapolated from the plot of KCT value versus ASt unit content to zero ASt unit content, but was found to be much higher than the limiting value, in contradiction to the results obtained with maleic anhydride (MAnh). The entropy of complex formation with DMT was found to be exceptionally small; this small value may be responsible for the high KCT value with DMT.

Syntheses of dinuclear titanium constrained geometry complexes with polymethylene bridges and their copolymerization properties

Homo- and copolymerizations of butadiene (BD) and styrene (St) with rare-earth metal catalysts, including the most active neodymium (Nd)-based catalysts, have been examined, and the cis-1,4 polymerization mechanism was investigated by the diad analysis of copolymers. Polymerization activity of BD was markedly affected not only by the ligands of the catalysts but also by the central rare-earth metals, whereas that of St was mainly affected by the ligands. In the series of Nd-based catalysts [Nd(OCOR)3:R = CF3, CCl3, CHCl2, CH2Cl, CH3], Nd(OCOCCl3)3 gave a maximum polymerization activity of BD, which decreased with increasing or decreasing the pKa value of the ligands. This tendency was different from that for Gd(OCOR)3 catalysts, where the CF3 derivative led to the highest polymerization activity of BD. For the polymerization of St and its copolymerization with BD, the maximum activities were attained at R = CCl3 for both Nd- and Gd-based catalysts. The copolymerization of BD and St with Nd(OCOCCl3)3 catalyst was also carried out at various monomer feed ratios, to evaluate the monomer reactivity ratios as rBD = 5.66 and rSt = 0.86. The cis-1,4 content in BD unit decreased with increasing St content in copolymers. From the diad analysis of copolymers, it was indicated that Nd(OCOCCl3)3 catalyst controls the cis-1,4 structure of the BD unit by a back-biting coordination of the penultimate BD unit. Furthermore, the long range coordination of polymer chain by the neodymium catalyst was suggested to assist the cis-1,4 polymerization. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 241–247, 1998

Approach to the synthesis, as well as results of phase state study, peculiarities of structure and optical properties of side-chain LC polymers with the helical organization (cholesterics and chiral smectics) and their blends with low molar mass liquid crystals are presented. Acrylic cholesterol-containing homopolymers and different copolymers containing the chiral (mesogenic and nonmesogenic) and the nematogenic (phenyl benzoate and cyanobiphenyl) groups were studied. The different derivatives of cholesterol and p-alkoxybenzoates were used as the low molar mass liquid crystals. Some of cholesterol-containing homopolymers form the S A phase within the wide interval from room temperture up to about 155°C, the cholesteric phase -within interval of 4--5 °C and within the narrow temperature range (0.45 °C) -the blue phase. Structure and optical properties of copolymers as well as the blends of LC homoand copolymers with low molar mass liquid crystals depend on their compositions. The possibility to form either monochromic or enantiochromic cholesteric phase is shown. The cholesteric polymeric films are characterized by selective reflection of circular polarized light. The wavelength of selective reflection of light depends on the chemical structure of the chiral and the nematogenic components as well as on their content in copolymers and in blends. The helical twisting power of the chiral component as well as temperature dependence of the cholesteric helix pitch are discussed. The influence of the electric field on the helix pitch is demonstrated.

This study has demonstrated that high-throughput FTIR transmission measurements using a newly designed array-based support formed using silicon wells and a silicon wafer is a very useful and robust tool for the characterization of polymer composition for combinatorial materials research. The comonomer content in copolymers can be measured accurately with a fully automated throughput of >300 samples/day (8 h). The transmission measurement is more robust, reliable, and easier to automate than other spectroscopic methods. The support itself provides excellent resistance to aggressive organic solvents at elevated temperatures and allows the unattended deposition and preparation of polymer films for infrared analysis. Because of the excellent durability of the support with respect to the solvent, the support can be rinsed and reused many times. This high-throughput approach to infrared transmission spectroscopy can be used for measuring a wide array of polymer characteristics: vinyl content, geometrical isomers, crystallinity, and tacticity. As well, this IR approach can be used to predict the oxidative stability of the antioxidant packages. Because the support provides a means of containing hot polymer solutions while the solvent evaporates, the support is also suitable for high-throughput nanoindentation methods for the determination of modulus and other physical properties of the polymer.