Structures and Properties of Thermoregulated Acrylonitrile-Methyl Acrylate Sheet Containing Microphase Change Materials

摘要

A 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 ~(13)C-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 cya-nogroup). 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 (T_g) of the sheets was in the range of 79.7-81.7°C, which also increased with the micro-PCMs content increasing