Structures and properties of thermoregulated acrylonitrile–methyl acrylate sheet containing microphase change materials

Abstract

AbstractA series of melt processable poly(acrylonitrile–methyl acrylate) copolymers with a feeding ratio of 85/15 mol% (abbreviated as 85/15 AN/MA below) containing 0–25 wt% of microencapsulated phase change materials (micro‐PCMs) were synthesized by aqueous precipitation polymerization. The number average sequence lengths (NASLs) and tacticity of 85/15 AN/MA were determined using 13C‐NMR. The results showed that the NASL of contiguous AN sequences is 10.00 and the tacticity is atactic with approximately 51% m and 49% r diads (the relative orientation of two adjacent cyanogroup). 85/15 AN/MA containing various contents of micro‐PCMs were processed into sheets in melt condition at 210°C and 20 MPa. The structures and properties of the copolymers and sheets containing micro‐PCMs were studied by using Fourier transform infrared spectroscopy, nuclear magnetic resonance (1H‐NMR), scanning electron microscopy, differential scanning calorimetry, gel permeation chromatography, X‐ray diffraction, and dynamic mechanical analysis. The composition of AN/MA copolymer agreed well with its monomer feed ratio. The melting enthalpy of the sheets containing 25 wt% of micro‐PCMs was approximately 25 J/g, which increased steadily as the micro‐PCMs content increased. The modulus of the sheets decreased with the micro‐PCMs content increased. The glass transition temperature (Tg) of the sheets was in the range of 79.7–81.7°C, which also increased with the micro‐PCMs content increasing. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers