Polyarylates glass transition temperature

The glass transition temperatures (Tgs) of polyarylates derived from substituted HQs and substituted PECs are shown above in Table 19.1. Polyarylates containing bulky substituents, such as / Ifu, on the HQ units exhibit above high glass transitions due to the high rigidity of their molecular structures. Thus, fBu-HQ/PEC shows a high Tg of 146 °C when compared to that of Me-HQ/PEC (104 °C). 

Kanemitsu and Einami (1990) investigated the role of the polymer on hole transport in a series of 2-(p-dipropylaminophenyl)-4-(p-dimethylaminophenyl)-5-(o-chlorophenyl)-l,3-oxazole (OX) doped polymers. The polymers were a polyarylate (PA), bisphenol-A polycarbonate (PC), poly(methyl methacrylate) (PMMA), poly(styrene) PS, poly(vinyl chloride) (PVC), polyethylene terephthalate) (PET), and poly(vinyl butyral) (PVB). The glass transition temperatures of the polymers range from 322 (PVB) to 448 K (PA). The temporal features of the photocurrent transients were strongly dependent on the polymer. Figure 76 shows the results. The field was 4.0 x H)5 V/cm and the temperature 295 K. The transients were near rectangular for PS, PET, PA, and PMMA, and highly dispersive for PVC land PVB. This was attributed to the fact... 

Literature procedures were followed for the preparation of polycarbonates (21), polyarylates (2JEL) and polyetherimides (22.) from different bisphenol monomers. Glass transition temperatures were determined using a Perkin Elmer DSC-7 differential scanning calorimeter. Densities of the substituted polymer films were determined by floatation in potassium iodide gradient columns at 23 °C. 

Polyarylate/PET blends prepared by solution or melt blending under short residence times at T < 280°C with or without an added ester interchange inhibitor such as triphenylphosphite, are essentially phase-separated, exhibiting two glass transition temperatures, one each for a PET phase and a polyarylate-rich phase. From the observed glass transition temperamres, one can conclude that it is a partially miscible blend in which more PET dissolves in the polyarylate phase than polyarylate does in PET. The interaction parameter has been estimated to be slightly positive (Xj = 0-1) [Chung and Akkapeddi, 1993]. 

FIGURE 52 The dependence of glass transition temperature on macromolecular coil fiactal dimension in tetrachloroethane for copolymers polyarylate-polyarylenesulfonoxide. The points—experimental data the straight line—calculation according to the Eqs. (14) of Chapter 1 and (95)-(97). 

The experimental studies of reactions in polymers confirmed the correctness of the approach [18] as a whole and the Eq. (106) of Chapter 2 and Eq. (6) in particular [19]. The authors [20, 21] elaborated the dimension d determination technique and verified its correctness on the example of two polymers melt polyarylate (PAr) and block-copolymer polyarylat-earylenesulfoxide (PAASO). These polymers polycondensation mode and their main characteristics (glass transition temperature T, mean weight molecular weight M and thermooxidative degradation rate k) are adduced in Table 3. 

FIGURE 61 The dependence of glass transition temperature on macromolecular coil fractal dimension for polyarylates of series Ph (1) and D (2). The curve is theoretical calculation, the points are experimental data. 

This paper is devoted to a study of the physical blends and transreacted copolymer products of a polyarylate (PAr) and bis-phenol-A polycarbonate (PC). Both polymers are amorphous thermoplastics of relatively high glass transition temperatures. 

Figure 6a Glass transition temperatures of tyrosine-derived polyarylates. In this three dimensional presentation, the pendent chain length is plotted on the y axis, the length of the diacid component in the polymer backbone is plotted on the x axis, and the measured glass transition temperatures are plotted on the z axis.

Amoco [7] reported several polyaryl ether-sulfones to be miscible with each other. The miscible blend comprises a 1,4-arylene unit separated by ether oxygen and another resin 1,4 arylene separated by an SO2 radical. The miscible blends showed a single glass transition temperature in between the constituent values. The blend was transparent. These can be used for printing wiring board structures, electrical connectors, and other fabricated articles that require high heat and chemical resistance and good dimensional and hydrolytic stability. 

The property profile (mechanical, electrical, thermal, and combustion) of Ardel D-lOO (Bisphenol A polyarylate) is listed in Tables I through IV, respectively. The dynamic mechanical data are illustrated in Figure 3 for Ardel D-lOO showing the high glass transition temperature and consistent modulus over a large temperature range. 

Guggenheim, et al demonstrated that the cyclic arylates can be polymerized at elevated temperature (360° C) in the presence of an anionic initiator. The polymerization of a cyclics/polymer mixture, which has a lower melting point, can be carried out at a somewhat lower temperature. The individual cyclics melt at about 385° C with polymerization occurring, even in the absence of catalyst. Polymerization leads to polyaiylates with wt. avg. MW of about 40-60,000, and the expected glass transition temperatures (bisphenol A polyarylate, Tg = 167° C, spirobiindane polyarylate, Tg = 242° C). 

In Fig. 1.4, the dependences v j(7) for polycarbonate (PC) and polyarylate (PAr) are adduced. These dependences show v, reduction at T growth, that assumes local order regions (clusters) thermofluctuational nature. Besides, on the indicated dependences two characteristic temperatures are found easily. The first from them, glass transition temperature F, defines clusters fixll decay (see also Fig. 1.1), the second corresponds to the fold on curves v j(7) and settles down on about 50 K lower T. ... 

This relationship graphic interpretation for amorphous glassy polymers -polycarbonate (PC) and polyarylate (PAr) - is adduced in Fig. 1.1. Since at r = r (T ) (where T, T and are testing, glass transition and melting temperatures, accordingly) AG =0[10 11], then from the Eq. (1.1) it follows, that at the indicated temperatures cluster structure full decay (9, = 0) should be occurred or transition to thermodynamically equilibrium structure. 

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