Giebler Michael, Sperling Clemens, Kaiser Simon, Duretek Ivica, Schlögl Sandra
Polymer Competence Center Leoben GmbH, Roseggerstrasse 12, A-8700 Leoben, Austria.
Chair of Polymer Processing, Montanuniversitaet Leoben, Otto Gloeckel-Strasse 2, A-8700 Leoben, Austria.
Polymers (Basel). 2020 May 17;12(5):1148. doi: 10.3390/polym12051148.
Epoxy-anhydride vitrimers are covalent adaptable networks, which undergo associative bond exchange reactions at elevated temperature. Their service temperature is influenced by the glass transition temperature () as well as the topology freezing transition temperature (), at which the covalent bond exchange reactions become significantly fast. The present work highlights the design of high- epoxy-anhydride vitrimers that comprise an efficient stress relaxation at elevated temperature. Networks are prepared by thermally curing aminoglycidyl monomers with glutaric anhydride in different stoichiometric ratios. The tertiary amine groups present in the structure of the aminoglycidyl derivatives not only accelerate the curing reaction but also catalyse the transesterification reaction above , as shown in stress relaxation measurements. The topology rearrangements render the networks recyclable, which is demonstrated by reprocessing a grinded powder of the cured materials in a hot press. The epoxy-anhydride vitrimers are characterised by a high (up to 140 °C) and an adequate storage modulus at 25 °C (~2.5 GPa), which makes them interesting candidates for structural applications operating at high service temperature.
环氧-酸酐类热致液晶聚合物是共价自适应网络，在高温下会发生缔合键交换反应。它们的使用温度受玻璃化转变温度（）以及拓扑冻结转变温度（）的影响，在拓扑冻结转变温度下，共价键交换反应会显著加快。目前的工作重点是设计一种高温环氧-酸酐类热致液晶聚合物，该聚合物在高温下具有高效的应力松弛性能。通过以不同化学计量比将氨基缩水甘油单体与戊二酸酐进行热固化来制备网络。氨基缩水甘油衍生物结构中存在的叔胺基团不仅加速固化反应，还能催化高于的酯交换反应，如应力松弛测量所示。拓扑重排使网络具有可回收性，这通过在热压机中对固化材料的研磨粉末进行再加工得到了证明。环氧-酸酐类热致液晶聚合物的特点是具有较高的（高达140°C），并且在25°C时具有适当的储能模量（约2.5 GPa），这使其成为在高使用温度下运行的结构应用的有趣候选材料。
