Multiblock poly(ether‐ester‐amide)s based on polyamide‐6 and poly(ethylene glycol), 1. Effect of polyether segment length on the properties of poly(ether‐ester‐amide)s with various polyamide/polyether ratios

Abstract

A series of multiblock poly(ether-ester-amide)s (PEEA) based on polyamide-6 (PA6) and poly(ethy1ene glycol) (PEG) is synthesized in a two-step process. The first step represents the hydrolytic polymerization of E-caprolactam (CL) in the presence of adipic acid (AA) to carboxylterminated PA6 oligomers of different chain lengths and the second is their polycondensation with PEG of molecular weights 420 (PEG 400) and 1 150 (PEG 1ooO) in the presence of catalyst and thermostabilizer. The formation of the new ester bond between PA6 and PEG is proved by infrared spectroscopy. The content of the hard (PA6) and the soft (PEG) segments in the copolymer is determined by 'H NMR and elemental analysis. The shift in glass transition temperature Tg above that of pure PEG and the depression of the melting temperature T, assigned to PA6 are characteristic for phase-separated block copolymers. The degree of crystallinity of the PA6 component does not seem to be affected by the actual weight composition but depends on the different segment lengths. For the copolymers containing PEG1000 it is close to that of the respective homopolymer PA6. The tensile parameters of the copolymers studied are similar to those of available PEEA products.

Structure and properties of thermoplastic poly(glycerol sebacate) elastomers originating from prepolymers with different molecular weights

“…Figure 4 displays the X-ray diffraction (XRD) patterns of the elastomers. The patterns of e 1 and e 2 present similar peaks, which are slightly different from that of e 3 . No matter how, these XRD peaks indicate that all the elastomers possessed similar crystal components or ordered structures at room temperature, which affected the mechanical properties, degradation performance, and so on of the elastomers.…”

“…In our previous work, 15 the sol content in the elastomer with the same molar ratio of sebacic acid to glycerol prepared by the one-step method was around 70%, prominently higher than that of e 1 and e 3 , and the swelling degree was about 3700%, also much higher than that of e 1 and e 3 . These illustrated that using the two-step method could make the gel content and crosslinking density of the elastomers bigger than using the one-step method.…”

“…Thermoplastic elastomers are usually phase-separated block copolymers, [1][2][3] whereas thermoset elastomers are formed sometimes by the crosslinking of starshaped prepolymers. [4][5][6][7][8] Thermoplastic and thermoset elastomers can be prepared by special methods.…”

Phase separation and physical properties of PEO-containing poly(ether ester amide)s

“…As can be seen in Table 2, the thermal properties of the PEEA copolymers vary signi cantly with the copolymer composition. Other poly(ether ester amide)s based on nylon-6 also showed such a dependence [27].…”

“…7C) is also of great in uence. The tensile behavior of PEEAs is typical of thermoplastic elastomers [27,48], showing high extensions and relatively high modulus values. The values of the mechanical properties are given in Table 4.…”