Kiangkitiwan Nopparut, Srikulkit Kawee
Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
ScientificWorldJournal. 2013 Nov 5;2013:860487. doi: 10.1155/2013/860487. eCollection 2013.
Poly(lactic acid), PLA, is a biodegradable polymer, but its applications are limited by its high cost and relatively poorer properties when compared to petroleum-based plastics. The addition of starch powder into PLA is one of the most promising efforts because starch is an abundant and cheap biopolymer. However, the challenge is the major problem associated with poor interfacial adhesion between the hydrophilic starch granules and the hydrophobic PLA, leading to poorer mechanical properties. In this paper, soybean oil maleate (SOMA) was synthesized by grafting soybean oil with various weight percents of maleic anhydride (MA) using dicumyl peroxide (DCP) as an initiator. Then, SOMA was employed for the surface modifying of cassava starch powder, resulting in SOMA-g-STARCH. The obtained SOMA-g-STARCH was mixed with PLA in various weight ratios using twin-screw extruder, resulting in PLA/SOMA-g-STARCH. Finally, the obtained PLA/SOMA-g-STARCH composites were prepared by a compression molding machines. The compatibility, thermal properties, morphology properties, and mechanical properties were characterized and evaluated. The results showed that the compatibility, surface appearance, and mechanical properties at 90 : 10 and 80 : 20 ratios of PLA/SOMA-g-STARCH were the best.
聚乳酸（PLA）是一种可生物降解的聚合物，但其应用受到高成本以及与石油基塑料相比相对较差性能的限制。在聚乳酸中添加淀粉粉末是最有前景的尝试之一，因为淀粉是一种丰富且廉价的生物聚合物。然而，挑战在于亲水性淀粉颗粒与疏水性聚乳酸之间存在较差的界面粘附性这一主要问题，导致机械性能较差。本文以过氧化二异丙苯（DCP）为引发剂，通过将不同重量百分比的马来酸酐（MA）接枝到大豆油上合成了马来酸酐大豆油（SOMA）。然后，将SOMA用于木薯淀粉粉末的表面改性，得到SOMA接枝淀粉（SOMA-g-STARCH）。使用双螺杆挤出机将所得的SOMA-g-STARCH与聚乳酸按不同重量比混合，得到聚乳酸/ SOMA-g-STARCH。最后，通过模压机制备所得的聚乳酸/ SOMA-g-STARCH复合材料。对其相容性、热性能、形态性能和机械性能进行了表征和评估。结果表明，聚乳酸/ SOMA-g-STARCH在90:10和80:20比例下的相容性、表面外观和机械性能最佳。
