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Chain extenders for polyesters. III. Addition‐type nitrogen‐containing chain extenders reactive with hydroxyl end groups of polyesters
Author(s) -
Inata Hiroo,
Matsumura Shunichi
Publication year - 1986
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1986.070320423
Subject(s) - polyester , intrinsic viscosity , polymer chemistry , extender , ethylene , materials science , chemistry , nuclear chemistry , organic chemistry , polymer , polyurethane , catalysis
Effective chain extenders for linear polyesters such as poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) were sought among some nitrogen‐containing bisheterocycles, which were reactive with hydroxyl terminals of the polyesters to form addition linkages. Tested were such bis cyclic‐imino‐esters as bis[5(4H)‐oxazolone]s (OXZ) and bis(4H‐3,1‐benzoxazin‐4‐one)s (BNZ), among which BNZ, especially 2,2′‐bis(4H‐3,1‐benzoxazin‐4‐one) (BNZ‐A‐1) has been proved to be a very effective chain extender for both PET and PBT. Starting from PET having intrinsic viscosity ([η]) of 0.52 and carboxyl content (CV) of 10 eq/10 6 g, addition of 1 mol % BNZ‐A‐1 resulted in PET having [η] of 1.11 and CV of 13 eq/10 6 g at a polyester melt temperature under atmospheric nitrogen within a few minutes. On the other hand, OXZ which were less thermally stable than BNZ could not act as good chain extenders for PET at a PET melt temperature. But they were effective in the case of PBT, which melted at a lower temperature than PET.