Effect of Composition on the Crystallization, Water Absorption, and Biodegradation of Poly(ε-caprolactam-co-ε-caprolactone) Copolymers

Abstract

Poly(ester amide)s have aroused extensive research interest due to the combination of the degradability of polyester and the higher mechanical properties of polyamide. In this work, a series of poly(ε-caprolactam-co-ε-caprolactone) (P(CLA-co-CLO)) copolymers with different compositions were synthesized by anionic copolymerization. The structure, crystallization behavior, water absorption, and biodegradation behavior of these copolymers were investigated by means of nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and polarized optical micrographs (POM). The results indicated that the composition of P(CLA-co-CLO) copolymers can be adjusted by the molar feed ratio. The PCL blocks decreased the crystallization rate of PA6 blocks but had little effect on the melting behavior of PA6, while the crystallized PA6 acted as a heterogeneous nucleating agent and greatly improved the crystallization rate of PCL. Moreover, the introduction of PCL blocks greatly reduced the water absorption of P(CLA-co-CLO) copolymers and endow them a certain degree of degradability.

Synthesis, Characterization, and the Potential for Closed Loop Recycling of Plant Oil-Based PA X.19 Polyamides

“…The water uptake of polyamides can further be influenced by the crystallinity of the polymer. It was shown that increasing the crystallinity of PA 6 by tempering resulted in a 30% reduction of the water uptake . The influence of crystallinity can be neglected, though, as the synthesized polyamides all have a similar crystallinity of approximately 50%.…”

Regulation of ester contents enabled tunable thermal and mechanical properties of poly(ester amide)

“…PEAs are widely used in the biomedical field and in elastomers. 17,19,20 On the other hand, PEAs obtained through ring-opening copolymerization offer a great potential in engineering plastics, [21][22][23][24][25] which can be regarded as modification of polyamides and polyesters.…”

“…As the classic representatives of polyamides and polyesters, polycaprolactam (polyamide 6, nylon 6), with higher thermal stability and good mechanical properties, [25][26][27][28][29] and polycaprolactone (PCL), with excellent biodegradability, [30][31][32][33][34] are indispensable for industry and everyday life. Thus, the synthesis of poly(ε-caprolactone-coε-caprolactam) has attracted great attention.…”