Kamjornsupamitr Trin, Hunt Andrew J, Supanchaiyamat Nontipa
Materials Chemistry Research Center, Department of Chemistry, Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University Khon Kaen 40002 Thailand
RSC Adv. 2018 Nov 6;8(65):37267-37276. doi: 10.1039/c8ra07133k. eCollection 2018 Nov 1.
Bio-based carboxyl-terminated hyperbranched crosslinkers have been synthesised by the facile esterification reaction of glycerol with succinic anhydride (Gly-SA). The Gly-SA crosslinking molecules have a large number of terminal carboxyl groups, which can crosslink through the epoxide of epoxidised soybean oil (ESO), making a highly flexible transparent film with excellent oxidative resistance. The effect of different molecular weights of Gly-SA cured ESO on the thermal and mechanical properties of the resulting films was also investigated. This study demonstrated that an increase in the molecular weights of Gly-SA, led to a decrease in the curing rate of mixtures, whilst the glass transition temperature ( ) of Gly-SA cured ESO increased due to the incorporation of the bulky crosslinker. The use of a Gly-SA crosslinker prepared at 150 °C, resulted in a film (EGS150) with a tensile strength 13 times greater than of the control film, exhibited more than a 220% increase in elongation at break and the Young's modulus quadrupled compared to the value obtained for the control sample. It is noteworthy that the tensile strength and elongation at break improved with increasing Gly-SA chain length, suggesting the pre-polymerised crosslinkers contribute to the enhanced mechanical properties of the materials.
通过甘油与琥珀酸酐（Gly-SA）的简便酯化反应合成了生物基羧基封端的超支化交联剂。Gly-SA交联分子具有大量的末端羧基，其可通过环氧化大豆油（ESO）的环氧化物进行交联，从而制成具有优异抗氧化性的高柔韧性透明薄膜。还研究了不同分子量的Gly-SA固化ESO对所得薄膜热性能和力学性能的影响。该研究表明，Gly-SA分子量的增加导致混合物固化速率降低，而由于加入了庞大的交联剂，Gly-SA固化ESO的玻璃化转变温度（ ）升高。使用在150℃制备的Gly-SA交联剂，得到的薄膜（EGS150）的拉伸强度比对照薄膜大13倍，断裂伸长率提高了220％以上，杨氏模量是对照样品的四倍。值得注意的是，拉伸强度和断裂伸长率随着Gly-SA链长的增加而提高，这表明预聚合的交联剂有助于提高材料的力学性能。
