Synthesis and Properties of PA6-PEG Copolymer

A series of PA6-PEG segmented copolymer was synthetized through anionic polymerization. The effect of caprolactam/PEG feeding ratio on thermal properties was focused on,and the performance of crystallization of the copolymer was also analyzed. The structure,thermal and crystalline properties of the products were studied with Fourier transform infrared spectroscopy,differential scanning calorimetry,XRD and other tests. The results showed that the products were segmented copolymers connected with ester bonds;the melting point declines regularly when the PEG mass percentage was less than 20%.However it had big volatility when the percentage was more than 20%,which could indicate that the caprolactam/PEG ratio was not the decisive factor of the melting point. The melting point of the copolymer went down when the relative molecular mass of PEG was low but the caprolactam/PEG ratio was the same. It was easier to get thermodynamically unsteady γ polymorph products by anionic polymerization.