The microstructure of poly(butylene terephthalate)copolymers via ~(13)C NMR sequence distribution analysis:Solid-state copolymerization versus melt copolymerization

摘要

Two diols, 2,2-bis(4-[hydroxyethoxy]phenyl)propane (Dianol 220~R)and bis(2-hydroxyethyl)terephthalate (BHET), were incorporated into poly(butylene terephthalate)(PBT)by solid-state polymerization (SSP)and melt polymerization (MP).Different PBT/diol ratios were used to obtain copolymers with different compositions.~(13)C NMR spectroscopy was used to analyze the sequence distribution and the data analysis was discussed in detail.Both Dianol and BHET were randomly incorporated in the MP copolymers.For both PBT-Dianol and PBT-BHET copolymers obtained via SSP, a non-random, blocky microstructure was obtained.For the PBT-Dianol copolymers, the randomness increased for increased fractions of incorporated Dianol.For the PBT-BHET copolymers, the randomness continuously decreased with increased fractions of incorporated BHET.