Liu Peng, Ling Jiandi, Mao Taoyan, Liu Feng, Zhou Wenzhi, Zhang Guojie, Xie Fengwei
School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
Molecules. 2023 Jun 4;28(11):4543. doi: 10.3390/molecules28114543.
Starch, being renewable and biodegradable, is a viable resource for developing sustainable and environmentally friendly materials. The potential of starch/Ca gels based on waxy corn starch (WCS), normal corn starch (NCS), and two high-amylose corn starches, G50 (55% amylose content) and G70 (68% amylose content) as flame-retardant adhesives has been explored. Being stored at 57% relative humidity (RH) for up to 30 days, the G50/Ca and G70/Ca gels were stable without water absorption or retrogradation. The starch gels with increasing amylose content displayed increased cohesion, as reflected by significantly higher tensile strength and fracture energy. All the four starch-based gels showed good adhesive properties on corrugated paper. For wooden boards, because of the slow diffusion of the gels, the adhesive abilities are weak initially but improve with storage extension. After storage, the adhesive abilities of the starch-based gels are essentially unchanged except for G70/Ca, which peels from a wood surface. Moreover, all the starch/Ca gels exhibited excellent flame retardancy with limiting oxygen index (LOI) values all around 60. A facile method for the preparation of starch-based flame-retardant adhesives simply by gelating starch with a CaCl solution, which can be used in paper or wood products, has been demonstrated.
淀粉作为可再生且可生物降解的物质，是开发可持续和环境友好型材料的可行资源。人们已经探索了以蜡质玉米淀粉（WCS）、普通玉米淀粉（NCS）以及两种高直链玉米淀粉G50（直链淀粉含量55%）和G70（直链淀粉含量68%）为基础制备的淀粉/Ca凝胶作为阻燃胶粘剂的潜力。在57%相对湿度（RH）下储存长达30天，G50/Ca和G70/Ca凝胶保持稳定，无吸水或回生现象。随着直链淀粉含量增加，淀粉凝胶的内聚力增强，这表现为拉伸强度和断裂能显著更高。所有四种淀粉基凝胶在瓦楞纸上均表现出良好的粘合性能。对于木板，由于凝胶扩散缓慢，初始粘合能力较弱，但随着储存时间延长而提高。储存后，除G70/Ca从木材表面剥离外，淀粉基凝胶的粘合能力基本不变。此外，所有淀粉/Ca凝胶均表现出优异的阻燃性，极限氧指数（LOI）值均在60左右。本文展示了一种通过用CaCl溶液使淀粉凝胶化来制备淀粉基阻燃胶粘剂的简便方法，该胶粘剂可用于纸制品或木制品。
