Polypropylene@ with high melt strength and crystallisation temp - prepd by reacting linear crystalline polypropylene@ with di-2-ethyl:hexyl peroxy:di:carbonate and kneading the melt

摘要

Polypropylene (PP) with high melt strength (IA) is claimed, contg. a linear crystalline PP with chain-branching coefft. = 1, which satisfies the conditions (A) and (B); and contains less than 1 wt.% residue which is extractable in boiling xylene. In the formulae, MS = melt strength at 230 deg.C; n = intrinsic viscosity in tetralin at 135 deg.C; Tc = recrystallisation temp. (by DSC); and Tm = m.pt. Also claimed are (i) processes for the prodn. of (I) and for reacting di-2-ethylhexyl peroxydicarbonate (EHPC) with linear crystalline PP to give (I); and (ii) moulded prods. made from (I). USE/ADVANTAGE - The invention enables the prodn. of PP with high melt strength and high crystallisation temp., combined with superior rigidity and ductility, which, after moulding, can be remelted and recycled.