Glass transition temperature aliphatic polyesters

TABLE 2.8 Melting Point, Tm (°C), and Glass Transition Temperature, 7 (°C), of Aliphatic, Aromatic-Aliphatic, and Cycloaliphatic Polyesters... 

TABLE 1 Glass Transition Temperatures of Aliphatic Polyesters... 

Cyclic oligomers of condensation polymers such as polycarbonates and polyesters have been known for quite some time. Early work by Carothers in the 1930s showed that preparation of aliphatic cyclic oligomers was possible via distillative depolymerization [1, 2], However, little interest in the all-aliphatics was generated, due to the low glass transition temperatures of these materials. Other small-ring, all-aliphatic cyclic ester systems, such as caprolactone, lactide... 

Crystalline polyesters from CHDM and aliphatic diacids are possible, but generally of little interest because of low melting points and low glass transition temperatures. Cyclic aliphatic diacids offer some potentially attractive possibilities. For example, the polyester of CHDM with a high-frans isomer 1,4-cyclohexanedicarboxylate has a melting point ( 225°C) similar to that of PBT [53],... 

Table 1. Monomer structures and polymer melting point and glass transition temperatures of the most common aliphatic polyesters obtained by ROP [2,7]...

Figure 6.26. Predicted melting temperature (Tm) and glass transition temperature (Tg), for aliphatic polyesters -[(CH2)k-COO-]n and polyamides -[(CH2)k-CON(H)-]n. All calculations were performed in absolute temperature units (K), although the results are shown above in °C.

Glass Transition Temperature. The of saturated polyester resins can be varied by a suitable choice of aromatic or aliphatic raw materials. The of nonplasticized... 

Another soft aliphatic polyester that may be used in manufacturing the pol5mer blends is poly(hydroxybutyTate-hydroxyvalerate) copolymer (PHBV), which is manufactured using a microbial-induced fermentation. One such PHBV copolyester is manufactured by Monsanto Company and has a glass transition temperature of about 0°C and a melting point of about 170°C. 

The glass transition temperature of isosorbide based aliphatic polyesters depending on the number of methylene groups in the aliphatic acid is shown in Figure 4.7. 

In contrast to aliphatic polyesters, for example terephthalic based polyesters show a much higher glass transition temperature of 155°C, or even higher, depending on the molar mass of the polyester (35,39). 

Figure 4.7 Glass Transition Temperature of isosorbide Based Aliphatic Polyesters Depending on the Number (n) of Methylene Groups in the Aliphatic Acid (34,35,41)...

Another class of soft aliphatic polyesters are based on repeating succinate units such as PBSU, poly(butylene succinate adipate) (PBSA), and poly(ethylene succinate) (PES). Each of these succinate-based aliphatic polyesters are manufactured by Showa High Polymer, Ltd. and are sold imder the trade name Bionolle . Glass transition temperatures (Tg) and melting points (T ) of tree types are shown in Table 4.6. 

In another vein, the polytransesterification of monomer 14, readily obtained from HMF, yielded the interesting material 15 because of the photosensitivity of the -2,5-Fu—CO—CH=CH— moiety (see Section 6.7.2) which reacted by coupling with another such moiety (statistically belonging to another polyester chain), thus ultimately providing a rigid crosslinked product. Copolymers based on 14 and aliphatic hydroxyesters were also prepared and the ensuing crosslinked materials displayed glass transition temperatures well below room temperature and were therefore elastomers [40]. 

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