We wish to thank Mr K. J. Toole;
the ManagingD irector of B&T Polymers and Mr D. Drury of the same companyfo r their supportW. e are also gratefutl o Mr P. Howgateo f RAPRA for initially suggestintgh e project;
and Mr L. Q. Hawe of University of Ulster for his constanth elp. S.N.R. would like to acknowledgwe ith gratitudeth e researchg rant from the Departmenot f Education for Northern Ireland;