SYNTHESIS OF A NEW MACROMONOMERIC PEROXYINITIATOR HAVING POLY(TETRAHYDROFURAN) UNITS

A new macromonomeric peroxyinitiator (MMPI) was synthesized by the rea ction of polytetrahydrofurandiol (p-THF-diol), M(w) 1000), isophorone diisocyanate, 2,5-dimethylhexyl-2,5-dihydroperoxide and 2-isocyanatoet hyl methacrylate. Homopolymerization of MMPI at 80 degrees C gave cros slinked polytetrahydrofuran (poly-THF) with swelling ratios in CHCl3 v arying between 1.4 and 4.2. Styrene polymerization initiated by MMPI a t 80 degrees C in bulk gave crosslinked poly-THF-b-polystyrene block c opolymers. The overall rate constant, k, was found to be 1 . 10(-4) (L mol(-1))(1/2) s(-1) by keeping the polymer yield below 15%. Swelling ratios of the crosslinked block copolymers in CHCl3 were between 2.7 a nd 75 according to the concentration of MMPI and the polymerization ti me. In case the MMPI concentration was kept constant while the polymer ization time was increased, swelling ratios were found between 3.55 an d 7.07. Thermogravimetric analysis showed that the crosslinked block c opolymers were still containing undecomposed peroxy groups, so they ca n thermally initiate styrene polymerization in order to obtain multico mponent cross-linked copolymers.