Synthesis and thermoanalysis of emulsion terpolymers of N-phenylmaleimide,styrene, and acrylonitrile

Terpolymers of N-phenylmaleimide (PMI), styrene, and acrylonitrile (AN) wer e synthesized by emulsion polymerization. The thermal properties of terpoly mers at different PMI and AN feed contents were investigated by differentia l scanning calorimetry, torsional braid analysis, thermogravimetric analysi s, and a Vicat softening point test. The results showed the glass-transitio n temperature and decomposition temperature of the terpolymers increased wi th increasing PMI feed content. Furthermore, the Vicat softening point of t he terpolymers rose with PMI feed content. The weight- and number-average m olecular weights ((M) over bar (w) and (M) over bar (n) ) of the terpolymer s were also determined by gel permeation chromatography. The results showed that the (M) over bar (w) and (M) over bar (n) of the terpolymers decrease d with increasing PMI feed content and increased with increasing AN feed co ntent. The mechanical properties (tensile strength and impact strength) of the terpolymers decreased with increasing PMI feed content and increased wi th increasing AN feed content. (C) 2000 John Wiley & Sons, Inc.