Abstract: The crystallization behavior of poly (methyl methacrylate-b-tetrahydrofuran) diblockcopolymer (PMMA-b-PTHF) and its blends with PTHF homopolymer has been studiedusing DSC technique.Because the crystallization of the PTHF block of the copolymer isstrongly hampered by the amorphous PMMA block of the copolymer.only a very small peakat very low temperature is observed in its DSC thermogram obtained during cooling, indi-cating a very low nucleation rate and a very low crystallinity.However, it was found thatthe copolymer in PMMA-b-PTHF/PTHF blends crystallizes at a much higher temperatureduring meling and a much higher crystallinity was detected.It may resulte mainly fromthe favorable conformation of the crystallizable block in blends.

Key words: polymethyl methacrylate, polytetrahydrofuran, block copolymer, blend, crystallization