Effects of copolymerization temperatures on structure and properties of melt-spinnable acrylonitrile-methyl acrylate copolymers and fibers

Abstract

A series of 85/15 AN/MA copolymers (acrylonitrile-methyl acrylate copolymers with feed ratio of 85/ 15 mol%) were synthesized by aqueous precipitation polymerization at 20, 30, and 40 °C, and the copolymers were used to produce a series of fibers by melt spinning. The copolymers and fibers were characterized by element analysis (EA), nuclear magnetic resonance ( 1H NMR and 13C NMR), capillary rheometry, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electronic microscopy (SEM). The average length of the contiguous AN units synthesized at 30 °C had a maximum value of 10.53. Aqueous polymerization at 30 °C resulted the lowest glass transition temperature (Tg) of 87.1 °C, the lowest melting point (Tm) of 154.5 °C, and the highest decomposition temperature (Td) of 325.0 °C. 85/15 AN/MA prepared at 20 and 30 °C exhibited a better fluidity at 210 °C. The ideal reaction temperatures for melt processing of the AN/MA copolymers were found to be 20 and 30 °C.