title: Effects of heat pretreatment of starch on graft copolymerization reaction and performance of resulting starch-based wood adhesive.
abstract: In this study, effects of starch heat pretreatment at 70, 80 and 90°C on graft copolymerization reaction with vinyl acetate (VAc) and the performance of the resulting starch-based wood adhesive (SWA) were investigated. It was shown that SWA pretreated at 90°C achieved the best performance. At this temperature, the bonding capacity improved by 17.84% compared to the adhesive synthesized without heat pretreatment and the viscosity increased by 18.16% after 7 free-thaw cycles, much better than other samples. Scanning electron microscopy (SEM) and polarizing microscopy demonstrated that structures of starch granules were fully damaged after heat pretreatment at 90°C. The reaction took place not only on the surface of starch granules, but also internally, leading to improvement in the grafting amounts and grafting efficiency by 42.86% and 39.03%, respectively. This was further confirmed by Fourier transform infrared spectroscopy (FT-IR), Confocal Raman microscopy (CRM) and X-ray photoelectron spectroscopy (XPS), which also showed better reaction homogeneity both between different starch granules and from granule surface to its internal structure.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China.
authors.forename: Xianyu
authors.initials: X
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China. Electronic address: chenglichocolate@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China. Electronic address: zhengbiaogu@jiangnan.edu.cn.
authors.forename: Zhengbiao
authors.initials: Z
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Hong
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China.
authors.forename: Zhaofeng
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China.
authors.forename: Caiming
authors.initials: C
authors.lastname: Li
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D004355:Drug Stability; D006358:Hot Temperature; D058105:Polymerization; D013213:Starch / Q000737:chemistry*; D013499:Surface Properties; D014783:Viscosity; D014934:Wood / Q000737:chemistry*
chemical_list: D000269:Adhesives; D013213:Starch
keywords: Graft copolymerization; Heat pretreatment; Starch-based wood adhesive performance