大豆7S与11S球蛋白尿素变性后的粘接性质研究

Study on adhesive property of 7S and 11S soy proteins modified with urea

随着人们对环境保护意识的增加和地球有限资源的缺乏,大豆蛋白在胶粘剂工业中的应用也越来越显示出强大的吸引力,鉴于前人的研究成果,文章研究了大豆7S和11S球蛋白经过尿素变性后在松木、樱桃木和胡桃木上的粘接强度和湿润能力。结果表明在不同的木块上不同胶粘剂有不同的粘接强度和湿润性能。7S大豆蛋白尿素变性后在硬木上有较好的湿润性。1M尿素变性赋予11S蛋白的粘接强度最高,3M尿素变性后,7S蛋白在硬木上的粘接强度大于11S蛋白。蛋白质的二级结构测量表明β-折叠对于3 M尿素变性后的大豆蛋白在硬木上的粘接强度起着重要作用,而无规则卷曲是降低1 M尿素变性7S大豆蛋白粘接强度的主要因素。

Soy proteins have shown great potential for adhesive and resin characterized the wettability and adhesive properties of the major soy protein glycinin（ 11S）after urea modification and found out the secondary structures p strength applications. This investigation compdnents conglycinin （7S）and laying key roles on the adhesive of 7S and 11S proteins after modifying with urea. These globulins were extracted from defatted soy flour, and then modified with urea. Modified 7S and llS soy proteins were evaluated for gluing strength with pine, walnut,and cherry plywood and for wettability using a bubble shape analyzer. The results showed that different adhesives had different wettability on different wood specimens. 7S soy protein modified with urea had the better wettability on hardwood. The 1 M urea modification gave 11S soy protein the highest adhesive strength in all the wood specimens. 7S soy protein modified with 3 M urea had higher adhesive strength with hardwood than llS soy protein modified with 3 M urea. Protein secondary structures measurement indicated that the β-sheet played an important role on the adhesive strength of soy protein modified with 3 M urea with hardwood and random curl was the major factor reducing adhesive strength of 7S soy protein modified with 1 M urea.