Advanced Polymerization and Properties of Biobased High Tg polyester of Isosorbide and 1,4-Cyclohexanedicarboxylic Acid through in Situ Acetylation

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• 作者：Won Jae Yoon ; Kwang Sei Oh ; Jun Mo Koo ; Jong Ryang Kim ; Kee Jung Lee ; Seung Soon Im
• 刊名：Macromolecules
• 出版年：2013
• 出版时间：April 23, 2013
• 年：2013
• 卷：46
• 期：8
• 页码：2930-2940
• 全文大小：690K
• 年卷期：v.46,no.8(April 23, 2013)
• ISSN：1520-5835

文摘

The synthetic problems associated with melt polymerizations to form homopolyesters of isosorbide (ISB) and rigid diacids could potentially be solved by using catalyst systems with acetic anhydride (Ac₂O). A catalyst consisting of dibutyltin oxide, germanium oxide, and Ac₂O exhibited excellent performance characteristics in syntheses of a high-molecular-weight homopolyester of ISB and cis/trans-1,4-cyclohexanedicarboxylic acid (CHDA), also referred to as poly(isosorbide cis/trans-1,4-cyclohexanedicarboxylate) (PICD). The acetylation of ISB using Ac₂O during esterification decreased the steric hindrance of ISB and accelerated the chain growth of PICD. Gel permeation chromatography data confirmed the formation of a high-molecular-weight PICD (71鈥?00 weight-average molecular weight and 14鈥?00 number-average molecular weight) using 0.02 mol of Ac₂O. The glass transition temperature of PICD was almost 131 掳C at 0.02 mol of Ac₂O and decreased with increasing amounts of Ac₂O due to the breaking of the rigid ring of ISB at higher concentrations of Ac₂O. The structure of opened ring ISB was confirmed using two-dimensional nuclear magnetic resonance (NMR) and distortionless enhancement by polarization transfer NMR.