Glass transition temperature of poly

The thermal glass-transition temperatures of poly(vinyl acetal)s can be determined by dynamic mechanical analysis, differential scanning calorimetry, and nmr techniques (31). The thermal glass-transition temperature of poly(vinyl acetal) resins prepared from aliphatic aldehydes can be estimated from empirical relationships such as equation 1 where OH and OAc are the weight percent of vinyl alcohol and vinyl acetate units and C is the number of carbons in the chain derived from the aldehyde. The symbols with subscripts are the corresponding values for a standard (s) resin with known parameters (32). The formula accurately predicts that resin T increases as vinyl alcohol content increases, and decreases as vinyl acetate content and aldehyde carbon chain length increases. 

The melting transition temperature and the heat of fusion of poly(nHAMCL) prepared from various alkanoic acids are collected in Table 5. The glass transition temperatures of poly(nHAMCL)s are usually between -30°C and -20°C. 

Glass Transition Temperatures of Poly (4-Alkyl Styrenes)... 

Table 1. Glass transition temperature of poly(arylene ether phenylquinoxaline) ...

Table 2. Glass transition temperatures of poly(arylene ether quinoxaline)s...

Nair, R., N. Nyamweya, S. Gonen, L J. Martinez-Miranda, and S. W Hoag. 2001. In uence of various drugs on the glass transition temperature of poly(vinylpyrolidone) a thermodynamic and spectroscopic investigation]nt. J. Pharm225 83-96. 

Polymers produced at high catalyst concentrations have low molecular weights, consistent with melting over a broad temperature range (150-350°C). At low catalyst concentrations, crystalline polymers (which do not melt even at temperatures as high as about 400° C) may be produced if the catalyst is a chiral metallocene. Another important property of a polymer is the glass transition temperature, which is the temperature at which the polymer becomes flexible. The glass transition temperature of poly(cyclo-pentene) is about 65°C. 

FIG. 6.2 Glass transition temperature of poly(methyl methacrylate) with paraffinic side groups. Estimated values Eqs. (6.6)—(6.8) Experimental values. 

Estimate the glass transition temperature of poly(hexadecyl methacrylate). Solution... 

Siahkolah, M. A., The Effect of Glass Transition Temperature of Poly-... 

Several fundamental studies of morphology and glass transition temperatures of poly(urethane-seq-diene) networks have been published 144,211 216). Phase separation was characterized by electron microscopy. 

Fig. 5 Fracture energy and glass transition temperature of poly(ether imide) PEI, A,A,A, A -tetra-glycidyl-4,4 -diaminodiphenylmethane, and diaminodiphenylsulphone. (From Ref. . )...

Tomic, E.A.J. 1965. Glass transition temperatures of poly(methyl methacrylate) plasticized with low concentrations of monomer and diethyl phthalate. Applied Polymer Science 9, 3745-3818. 

Octadecyl methacrylate (ODMA) can be polymerized by electron beam irradiation (9). When ODMA is used as the monomer with PTCEM as the base polymer, the resolution and line profile of the PDE is poor. This poor performance may be in part due to the low glass transition temperature of poly(octadecyl methacrylate) (PODMA) and the small plasma etch rate difference between PODMA and PTCEM. 

The glass transition temperature of poly(vinyl fluoride) was determined to be 43°C. The transition is independent of the molecular weight of the polymer. Polymers, for this study, were prepared in the presence of a variety of initiators such as 2,2 -azobisisobutyronitrile, tributylborane monoperoxide, or diisopropyl diperoxycarbonate [17]. 

However, as shown in Table 12, the glass transition temperature of poly 6-[4 -(4"-methoxyphenoxycarbonyl)phenoxy]hexyl methacrylate] is essentially independent of tacticity. With the exception of the polymer prepared by anionic polymerization [45], the nematic-isotropic transition also appears to be independent of tacticity. However, as demonstrated by the data in Fig. 8, the extrapolated transition temperatures (G 44 N 105 I) of an infinite molecular weight polymer prepared by anionic polymerization are nearly identical to those of the rest of the polymers presented in Table 12. 

Teng, H., Koike, K., Zhou, D., Satoh, Z., and Koike, Y. 2009. High glass transition temperatures of poly(methyl methacrylate) prepared by free radical initiators. /. Polym. Sci. Polym. Chem. 47 315-317. 

Mina, M. R, Ania, R, Rluy, T. A., Michler, G. H., and Balta Calleja, P. J. 2004. Micromechanical behavior and glass transition temperature of poly(methyl methacrylate)-rubber blends. Journal of Macromolecular Science B Physics 43(5) 947-961. 

Figure 12.43. Glass transition temperature of poly(phenylene oxide) composite systems as a function of filler concentration. The upper curve is for attapulgite-filled phenoxy, the lower curve for glass-bead-filled phenoxy. (Drdste and DiBenedetto, 1969.)...

Figure 11.38. Glass transition temperature of poly(N-vinyl pyrrolidone) plastieized with different amounts of PEG having moleeular weight of 400 daltons and glycerin. [Data from Feldstein M M Shandryuk G A Plate N A, Polymer, 42, No.3, 2001, p.971-9.]...

Considerable quantities of styrene are used in producing copolymerisates and blends, as, for example, in the production of copolymers with acrylonitrile (SAN), terpolymers from styrene/acrylonitrile/butadiene (ABS polymers) or acrylonitrile/styrene/acrylic ester (ASA), etc. The glass transition temperature of poly (styrene), 100 C, can be increased by copolymerization with a-methyl styrene. What are known as high impact poly (styrenes) are incompatible blends with poly(butadiene) or EPDM, which are consequently not transparent, but translucent. For this reason, pure poly (styrenes) are occasionally called crystal poly (styrenes). 

Also polymers with high attractive forces between chains will require more heat energy to go from a glassy to a rubbery or a plastic state. On the other hand, polymeric chains with loose hanging side chains that tend to loosen the polymer structure and increase the free volume for segmental movement will have lower Tg. For instance, the glass transition temperature of poly(methyl methacrylate) is higher than that of poly( -butyl methacrylate) as can be seen from Table 2.2. 

A Flory-Fox plot of the glass transition temperatures of poly-(isosorbide terephthalate) esters of different molar mass is shown in Figure 4.8. 

Figure 4.8 Fox-Flory Plot of the Glass Transition Temperatures of Poly-(isosorbide terephthalate) (35,39)...

---