Žiganova Madara, Merijs-Meri Remo, Zicāns Jānis, Bochkov Ivan, Ivanova Tatjana, Vīgants Armands, Ence Enno, Štrausa Evita
Institute of Polymer Materials, Faculty of Materials Science and Applied Chemistry, Riga Technical University, 3 Paula Valdena Street, LV-1048 Riga, Latvia.
Laboratory of Bioconversion of Carbohydrates, University of Latvia, 1 Jelgavas Street, LV-1050 Riga, Latvia.
Polymers (Basel). 2023 Jun 29;15(13):2896. doi: 10.3390/polym15132896.
The current research is devoted to the investigation of the plasticization of polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-hydroxyvalerate (PHBV) with triethyl citrate (TEC). Three different PHB or PHBV-based systems with 10, 20, and 30 wt.% of TEC were prepared by two-roll milling. The effect of TEC on the rheological, thermal, mechanical, and calorimetric properties of the developed compression-molded PHB and PHBV-based systems was determined. It was revealed that the addition of TEC significantly influenced the melting behavior of both polyhydroxyalkanoates (PHA), reducing their melting temperatures and decreasing viscosities. It was also revealed that all the investigated systems demonstrated less than 2% weight loss until 200 °C and rapid degradation did not occur until 240-260 °C in an oxidative environment. Apart from this, a remarkable increase (ca 2.5 times) in ultimate tensile deformation ε was observed by increasing the amount of TEC in either PHB or PHBV. A concomitant, considerable drop in ultimate strength and modulus of elasticity was observed. Comparatively, the plasticization efficiency of TEC was greater in the case of PHBV.
当前的研究致力于考察柠檬酸三乙酯（TEC）对聚羟基丁酸酯（PHB）和聚羟基丁酸酯 - 羟基戊酸酯共聚物（PHBV）的增塑作用。通过双辊研磨制备了三种不同的基于PHB或PHBV且含有10%、20%和30%（重量）TEC的体系。测定了TEC对所制得的压缩成型的基于PHB和PHBV体系的流变、热、机械和量热性能的影响。结果表明，TEC的添加显著影响了两种聚羟基链烷酸酯（PHA）的熔融行为，降低了它们的熔融温度并减小了黏度。还发现，在氧化环境中，所有研究的体系在200℃之前失重均小于2%，直到240 - 260℃才会发生快速降解。除此之外，通过增加PHB或PHBV中TEC的含量，观察到极限拉伸变形ε显著增加（约2.5倍）。同时，极限强度和弹性模量出现了相当程度的下降。相比之下，TEC对PHBV的增塑效率更高。
