摘要:
Polymers that have a number average molecular weight of at least 1000 and that contains at least 5% by weight of segments that contain at least two consecutively recurring cyclic ether units wherein at least one of said tetrahydropyran 2,6-diyl unit of the formula ##STR1## and wherein the remainder of said cyclic ether units are selected from said tetrahydropyran 2,6-diyl units and tetrahydrofuran 2,5-diyl units of the formula ##STR2## wherein R.sup.1, R.sup.8, R.sup.9, R.sup.10, R.sup.11, R.sup.12, R.sup.13 and R.sup.14 are each selected from hydrogen and lower alkyl groups;R.sup.2 and R.sup.7 are each selected from hydrogen, lower alkyl groups and aryl groups;R.sup.4 and R.sup.5 are each selected from hydrogen, lower alkyl groups, aryl groups and halo; andR.sup.3 and R.sup.6 are selected from hydrogen, lower alkyl groups and aryl groups or combine to form a divalent linking moiety having the formula ##STR3## wherein C.sup.7 and C.sup.8 are joined to the C.sup.3 and C.sup.5 positions respectively of said cyclic ether units; W, X, Y and Z are each monovalent groups or W and Z are each monovalent groups and X and Y combine to form a divalent linking moiety, that bridges between C.sup.7 and C.sup.8.