Poly , glass transition behavior

Tao W, Wei W, Yu C, Ren W, Qiaoling L. Influence of the mixing time on the phase structure and glass-transition behavior of poly(ethylene terephthalate)/poly(ethylene - 2,6 - naphthalate) blends. J Appl Polym Sci 2013 130(l) 673-9. 

S. C. Kim, D. Klempner, K. C. Frisch, and H. L. Frisch, Polyurethane Interpenetrating Polymer Networks II. Density and Glass Transition Behavior of Polyurethane-Poly(methyl methacrylate) and Polyurethane-Polystyrene IPNs, Macromolecules 9(2), 263 (1976). Polyurethane/Polymethacrylate SIN Polystyrene/Polyurethane SIN. Glass transition and density studies. 

If appreciable mixing between the component polymers occurs, the inward shift in the Tg of the two phases can each be expressed by the equations of Section 8.8.1 (125). Using equation (8.73), the extent of mixing within each phase in a simultaneous interpenetrating network of an epoxy resin and poly(n-butyl acrylate) was calculated (see Table 8.10). The overall composition was 80/20 epoxy/acrylic, and glycidyl methacrylate is shown to enhance molecular mixing between the chains. Chapter 13 provides additional material on the glass transition behavior of multicomponent materials. 

Foucher DA, Ziembinski R, Nang B-Z et al. (1993) Synthesis, characterization, glass transition behavior, and the electronic structure of high-molecular-weight, symmetrically substituted poly(ferrocenylsilanes) with alkyl or aryl side groups. Macromolecules 26 2878-2884... 

Song, M., Hammiche, A., Pollock, H.M., Hourston, D.J., and Reading, M. (1995) Modulated differential scanning calorimetry 1. A study of the glass transition behavior of blends of poly (methyl methacrylate) and poly(styrene-co-acrylonitrile). Polymer, 36, 3313—3316. 

Woo, E.M. and Chiang, C.P. (2004) Glass transition behavior and miscibility in blends of poly(vinyl p-phenol) with two homologous aliphatic polyesters. Polymer, 45, 8415-8424. 

Pedrosa, P., Pomposo, J.A., Calahorra, E., and Cortazar, M. (1994) On the glass transition behavior, interaction energies, and hydrogen bonding strengths of binary poly(p-vinylphenol) /polyether blends. Macromolecules, 27, 102-109. 

Bandi, S. Schiraldi, D. A. Glass Transition Behavior of Clay Aerogel/Poly(vinyl alcohol) Composites Macromolecules Vol. 39 pp 6537-6545,2006... 

The presence of three oxyethylene units in the spacer of PTEB slows down the crystallization from the meso-phase, which is a very rapid process in the analogous polybibenzoate with an all-methylene spacer, P8MB [13]. Other effects of the presence of ether groups in the spacer are the change from a monotropic behavior in P8MB to an enantiotropic one in PTEB, as well as the reduction in the glass transition temperature. This rather interesting behavior led us to perform a detailed study of the dynamic mechanical properties of copolymers of these two poly bibenzoates [41]. 

Park et al. [20] reported on the synthesis of poly-(chloroprene-co-isobutyl methacrylate) and its compati-bilizing effect in immiscible polychloroprene-poly(iso-butyl methacrylate) blends. A copolymer of chloroprene rubber (CR) and isobutyl methacrylate (iBMA) poly[CP-Co-(BMA)] and a graft copolymer of iBMA and poly-chloroprene [poly(CR-g-iBMA)] were prepared for comparison. Blends of CR and PiBMA are prepared by the solution casting technique using THF as the solvent. The morphology and glass-transition temperature behavior indicated that the blend is an immiscible one. It was found that both the copolymers can improve the miscibility, but the efficiency is higher in poly(CR-Co-iBMA) than in poly(CR-g-iBMA),... 

Philips R.A., McKenna J.M., and Cooper S.L., Glass transition and melting behavior of poly(ether-ester) multihlock copol3miers with poly(ethyleneterephthalate) hard segments, J. Polym. Sci. Part B, 32, 791, 1994. 

With continuous development of systems for controlled drug release, new materials are being used whose influence on peptide stability must be carefully examined. Thus, the model hexapeptide Val-Tyr-Pro-Asn-Gly-Ala (Fig. 6.30) embedded in poly (vinyl alcohol) and poly(vinyl pyrrolidone) matrices had rates of deamidation that increased with increasing water content or water activity, and, hence, with decreasing glass transition temperature (Tg). However, the degradation behavior in the two polymers differed so that chemical reactivity could not be predicted from water content, water activity, or T% alone. Furthermore, the hexapeptide was less stable in such hydrated polymeric matrices than in aqueous buffer or lyophilized polymer-free powders [132],... 

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