Chang Chih-Jen, Venkatesan Manikandan, Cho Chia-Jung, Chung Ping-Yu, Chandrasekar Jayashree, Lee Chen-Hung, Wang Hsin-Ta, Wong Chang-Ming, Kuo Chi-Ching
Institute of Organic and Polymeric Materials, Research and Development Center of Smart Textile Technology, National Taipei University of Technology, Taipei 10608, Taiwan.
Institute of Biotechnology and Chemical Engineering, I-Shou University, Kaohsiung 84001, Taiwan.
Polymers (Basel). 2022 May 11;14(10):1952. doi: 10.3390/polym14101952.
Starch-based biodegradable foams with a high starch content are developed using industrial starch as the base material and supercritical CO as blowing or foaming agents. The superior cushioning properties of these foams can lead to competitiveness in the market. Despite this, a weak melting strength property of starch is not sufficient to hold the foaming agents within it. Due to the rapid diffusion of foaming gas into the environment, it is difficult for starch to maintain pore structure in starch foams. Therefore, producing starch foam by using supercritical CO foaming gas faces severe challenges. To overcome this, we have synthesized thermoplastic starch (TPS) by dispersing starch into water or glycerin. Consecutively, the TPS surface was modified by compatibilizer silane A (SA) to improve the dispersion with poly(butylene adipate-co-terephthalate) (PBAT) to become (TPS with SA)/PBAT composite foam. Furthermore, the foam-forming process was optimized by varying the ratios of TPS and PBAT under different forming temperatures of 85 °C to 105 °C, and two different pressures, 17 Mpa and 23 Mpa were studied in detail. The obtained results indicate that the SA surface modification on TPS can influence the great compatibility with PBAT blended foams (foam density: 0.16 g/cm); whereas unmodified TPS and PBAT (foam density: 0.349 g/cm) exhibit high foam density, rigid foam structure, and poor tensile properties. In addition, we have found that the 80% TPS/20% PBAT foam can be achieved with good flexible properties. Because of this flexibility, lightweight and environment-friendly nature, we have the opportunity to resolve the strong demands from the packing market.
以工业淀粉为基础材料，采用超临界二氧化碳作为发泡剂，研制出了淀粉含量高的淀粉基可生物降解泡沫材料。这些泡沫材料优异的缓冲性能使其在市场上具有竞争力。尽管如此，淀粉较弱的熔体强度特性不足以将发泡剂保持在其中。由于发泡气体迅速扩散到环境中，淀粉难以在淀粉泡沫中维持孔隙结构。因此，使用超临界二氧化碳发泡气体生产淀粉泡沫面临严峻挑战。为克服这一问题，我们通过将淀粉分散在水或甘油中来合成热塑性淀粉（TPS）。随后，用相容剂硅烷A（SA）对TPS表面进行改性，以改善其与聚己二酸丁二醇酯-对苯二甲酸丁二醇酯（PBAT）的分散性，从而制成（含SA的TPS）/PBAT复合泡沫材料。此外，通过在85℃至105℃的不同成型温度下改变TPS和PBAT的比例来优化泡沫成型工艺，并详细研究了17MPa和23MPa这两种不同压力。所得结果表明，TPS的SA表面改性会影响其与PBAT共混泡沫材料的良好相容性（泡沫密度：0.16g/cm³）；而未改性的TPS和PBAT（泡沫密度：0.349g/cm³）则表现出高泡沫密度、刚性泡沫结构和较差的拉伸性能。此外，我们发现80%TPS/20%PBAT泡沫材料可具有良好的柔韧性。由于这种柔韧性、轻质和环保特性，我们有机会满足包装市场的强烈需求。
