Melting temperature poly

Figure 4.2 Melting temperature of crystals versus temperature of crystallization for poly( 1,4-cis-isoprene). Note the temperature range over which melting occurs. [Reprinted with permission from L. A. Wood and N. Bekkedahl, J. Appl. Phys. 17 362 (1946).]...

Fig. 2. CrystaUine melting temperatures of poly(viQylidene chloride) (40).

TABLE 2.7 Melting Temperatures of Isomeric Poly(alkylene terephthalate)s and... 

Another important type of condensation polymer are the linear polyesters, such as poly (ethylene terephthalate) (PET) and poly (butylene terephthalate) (PBT). Copolymers of polyesters and PA have been studied in detail, and it has been shown that random copolyesteramides have a low structural order and a low melting temperature. This is even the case for structurally similar systems such as when the group between the ester unit is the same as that between the amide unit, as in caprolactam-caprolactone copolymers (Fig. 3.10).22 Esters and amide units have different cell structures and the structures are not therefore isomorphous. If block copolymers are formed of ester and amide segments, then two melting temperatures are present. 

PAs have also been copolymerized with other polymer systems and, in particular", with polyesters and poly ethers. In the copoly esteramides the crystallinity is decreased by copolymerization, as the crystalline structure of the amide unit is very different from the ester unit. However, alternating polyesteramides behave as homopolymers with a glass ttansition temperature and a melting temperature intermediate to the polyester and the PA polymer (Figs. 3.10 and 3.11).23,24 Polyesters, such as PBT and PET, modified with a small amount of diamide are also copolymers that have a high order.24,73... 

Isomeric poly(alkylene terephthalate)s, melting temperatures of, 36 Isophthalaminonitrile, polymerization of, 344... 

V. Carlier, J. Devaux, R. Legras and D.J. Blundell, Extrapolation of short chain oligomers melting temperatures at infinite molecular weight, ]. Poly. Sci., Part B Poly. Pkys., 36 (1998) 2563-2571. 

Table 5. Melting temperature and heats of fusion of poly(nHAMCL)...

An X-ray diffraction study of PHA-10UND= showed that this PHA was amorphous however, the DSC thermogram of the polymer showed a small but clear endotherm at approximately 38 °C. The glass transition temperature of PHA-10UND= is approximately - 46 °C which is significantly lower than those of the poly(nHAMCL)s. Both the melting temperature and the glass transition tempe-... 

Poly(HASCL) (i.e. PHB and poly(3HB-co-3HV)) are typical thermoplastic polymers, which become fluid and moldable above their melting points, whereas poly(HAMCL)s generally are elastomers with low melting points. PHB has been reported to show a relatively high melting temperature of about 180°C, while the Tg of this polymer is approximately 9 °C [21,52,53]. Incorporation of 3HV-comonomer units into PHB decreases both the Tm as well as the Tg significantly. Poly(3HB-co-3HV), containing up to 28 mol% 3HV, has a Tm of about 102°C and a Tg of -8°C, respectively [21,52,53]. 

In an attempt to increase Tg of the poly[bis(o-carboxyphenoxy)alkanes], Anastasiou and Uhrich (2000a) replaced the alkane moiety by ortho-, meta-, and para-xylenes producing poly[o-/m-bis(p-carboxyphenoxy)xylene]s (Po-p-CPX, and Pm-p-CPX) and poly[o-/m-/p-bis(o-carboxyphenoxy)xylene]s (Po-o-CPX, Pm-o-CPX, and Pp-o-CPX). They found Po-p-CPX to be relatively insoluble and were unable to synthesize poly[p-bis(p-carboxy-phenoxy)xylene] because of the insolubility of the dicarboxylic acid (Anastasiou and Uhrich, 2000a). Po-o-CPX and Pm-o-CPX demonstrated the most favorable solubility and neither exhibited a melting temperature. All of the polymers synthesized had Tgs between 71 and 101°C (Anastasiou and Uhrich, 2000a). 

Fig. 10 PEO melting temperatures vs. inverse PEO domain size as a function of block architecture (squares, PS-6-PI-6-PEO diamonds PI-6-PS-6-PEO). PI poly(isoprene) w is given in angstroms. (Reprinted with permission from [121]. Copyright 2003 American Chemical Society)... 

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