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

Abstract

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 cyanogroup). 85/15 AN/MA containing various contents of micro-PCMs were processed into sheets in melt condition at 2108C 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 ( 1 H-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 79.7-81.78C, which also increased with the micro-PCMs content increasing. POLYM. COMPOS., 34:641-649, 2013. ª

Melt-Spinnable Polyacrylonitrile—An Alternative Carbon Fiber Precursor

“…The melt-processable AN copolymers with 15 mol.% of MA and M n ~20–40 kg⋅mol −1 obtained by precipitation and emulsion polymerization are described in [ 75 , 76 , 77 ]. These copolymers were used to produce hollow fibers with a tensile strength of 16 cN/dtex, elongation at break of 18.7%, and elastic modulus of 3 GPa [ 75 ]; films containing a microencapsulated phase change material [ 76 ] and membranes [ 77 ]. The formation of fibers, films, and membranes was conducted at 200–210 °C.…”