| Abstract: | A novel dualfunctional monomer,2-(2',2',6',6'-tetramethyl-piperidinyl-1'-oxy)methylbenzene-1,4-dioyl chloride hydrochioride,with two acid chloride groups for step-growth polymerization and a nitroxide group for the mediation of living radical polymerization was synthesized.It was first copolymerized with tercphthaloyl chloride and p-phenylenediamine at a feed molar ratio of 1:3:4 in N-methyl-2-pyrrolidone containing 10 wt% calcium chloride at -10℃ to yield a poly(p-phenylene terephthalamide) based macroinitiator,which initiated radical polymerization of styrene at 125℃ to obtain a series of poly(p-phenylene terephthalamide)-g-polystyrenes.A combinatory analysis of proton nuclear magnetic resonance spectroscopy,Fourier transform infrared spectroscopy,elementary analysis,thermogravimetry and gel permeation chromatography indicated that the macroinitiator induced the radical polymerization of styrene to proceed in a well-controlled way.The molecular weight of side-chains increased with an increase of monomer conversion,and the molecular weight distribution index remained lower than 1.5.The graft copolymers showed a remarkably improved solubility in N-methyl-2-pyrrolidone and much depressed crystallinity in bulk. |
