【作者】 李妍；

【导师】 王学川；

【作者基本信息】 陕西科技大学 ， 轻工技术与工程， 2018， 硕士

【摘要】 随着人造板业的迅速进步,对胶黏剂的需求量越来越大。由于“三醛胶”(脲醛树脂、酚醛树脂和三聚氰胺-甲醛树脂)的大量使用,对人类身体健康以及环境造成了危害,且“三醛胶”的生产原料主要来源于石油化工产品等不可再生资源。因此,研究开发新型绿色环保生物质基胶黏剂具有重要意义。我国制革行业在加工过程中每年约产生百万吨的皮革固体废弃物,其中含有丰富的皮胶原蛋白,传统的处理方式不仅会浪费资源,而且会污染环境。针对上述难题,本研究以从废弃皮中提取的工业明胶和胶原蛋白水解物为原料,通过对其进行交联改性制备胶黏剂,不仅制备出环境友好型的蛋白类胶黏剂,而且实现了皮革固体废弃物的资源化利用。首先,以废弃皮中提取的工业明胶(INGE)为原料,以十二烷基硫酸钠(SDS)为表面活性剂,环氧树脂(Ep)为交联剂,制备得到蛋白基胶黏剂(NGE/SDS/Ep)。通过单因素实验法和正交实验法优化了胶黏剂的制备条件,并且研究了改性前后胶黏剂固含量以及耐水性的变化,并对其结构、性能进行了表征和分析。通过单因素实验对胶黏剂应用于木板的热压工艺条件进行了优化,确定了制备INGE/SDS/Ep胶黏剂的最优合成条件。通过对其固含量及耐水性能进行测试,发现改性后INGE/SDS/Ep胶黏剂具有较高的固含量(33.42 wt.%),其耐水性能也比INGE/SDS胶黏剂了显著提升,使其胶黏木板样品的湿态剪切强度可达1.19 MPa,胶黏剂膜的水接触角提升到了85.8°。另外,通过系列研究,确定了其应用于木板施胶时的最佳热压工艺条件。其次,以从皮革固体废弃物中提取的胶原蛋白为原料,以异佛尔酮二异氰酸酯、聚乙二醇、2,2-二羟甲基丙酸为原料,合成了端异氰酸酯基聚氨酯预聚体交联剂。通过控制胶原蛋白水解物中氨基与聚氨酯预聚体中异氰酸酯基的摩尔比,合成了一系列不同的胶原蛋白基胶黏剂。通过FTIR、XRD、TG、GPC等手段对其性能及结构进行了检测和表征。并且采用单因素实验法优化了所合成胶黏剂应用于木板时的热压工艺条件。结果表明:以异氰酸酯基封端的聚氨酯预聚体改性胶原蛋白水解物,制得PU-COL系列胶黏剂中,PU-COL-1型胶黏剂性能最佳,其外观为淡黄色均匀乳液,固含量为38.16%,具有较好的稳定性。耐水性测试结果表明,在所有的PU-COL系列胶黏剂中,PU-COL-1型胶黏剂的耐水性最好,其湿态剪切强度可达1.08MPa。通过系列表征,确定了胶合木板的最佳热压工艺条件。最后,将本论文中合成的两种胶黏剂与市场上所应用的胶黏剂进行了性能对比。并通过各种检测及表征手段进行对比研究,结果表明,INGE/SDS/Ep胶黏剂(33.42 wt.%)和PU-COL-1胶黏剂(38.16 wt.%)的固含量明显比市售胶黏剂(21.67 wt.%)高,且两种胶黏剂粘结木板的耐水性以及膜本身的耐水性均优于市售胶黏剂。XRD检测显示两种胶黏剂的结晶性能较差,其结晶度远远低于市售胶黏剂,表明本论文合成的两种胶黏剂在低温下的应用性能更佳。另外,通过TG分析表明,本论文合成两种胶黏剂均具有较好的热稳定性。更多还原

【Abstract】 With the rapid development of plywood industry,the demand for adhesive is increasing.At present,the adhesives sold on the market are mainly"triple-formaldehyde"(urea-formaldehyderesin,phenolicresinand melamine-formaldehyderesin),andtherawmaterialsforthe"triple-formaldehyde"mainly come from non-renewable resources,and aldehyde resin and its products will also release free formaldehyde and other harmful substances that endanger human health.Millions of leather solid wastes are produced in the processing of leather.However,the traditional disposal methods will not only engender wasting of resouces,but also heavily pollute the environment.Actually,those wastes are rich in abundant collagens.Thus,the industrial gelatin and collagen hydrolyzate extracted from the leather wastes were used to prepara adhesives by crosslinking modification,which not only prepared environmentally friendly collagen-based adhesives,and also achieved resource utilization and reduced the environment pollution.Firstly,industrial gelatin(INGE),sodium hydroxide(NaOH),sodium dodecyl sulfate(SDS)and commercial epoxy resin(EP)were used to prepare collagen-based adhesive.Taking adhesive strength as index,the synthesis conditions were optimized by single factor experiment and orthogonal experiment.The changes of solid content and water resistance of the adhesive were studied.The structure and performance of the adhesive was characterized by FTIR,TG,XRD and SEM.The hot pressing conditions of the adhesive applied to the wood board are optimized by single factor experiment method.The results showed that the optimal conditions for the preparation of INGE/SDS/Ep adhesive were as follows:the reaction temperature was 50℃,the reaction system pH was 8,the reaction time was 2 h and the amount of epoxy resin was 8 g.Under this condition,the adhesive strength was 2.53 MPa.Results showed that a cross-linking network structure was formed by the reaction of epoxy resin with amino and hydroxyl groups in gelatin molecules,so that the crystallinity of the adhesive decreased and its water resistance was improved by240%.In addition,the solid content of adhesive increased to 33.42 wt%,the wet shear strength increased to 1.19 MPa(≥0.7 MPa),and the water contact angle increased to 85.8o.The TG result also showed that the thermostability of adhesive was improved.The SEM photographs showed that the surface of INGE/SDS/Ep adhesive film was smoother than INGE adhesive film.The optimal conditions of hot-pressing were as follows:the temperature was 100℃,the time was 5min and the amount of adhesive was 300 g/m~2.Secondly,a collagen based adhesive was prepared by using polyurethane prepolymer as the cross-linking agent,and collagen derived from tanned leather wastes as the raw material.Five different wood adhesives were obtained through controlling the molar rate of the amino group and the isocyanate group.The properties and structure were measured by solid content,water resistance and modern instrument characterization.The hot pressing conditions of the adhesive applied to the wood board are optimized by single factor experiment method.The results indicated that the water resistance was the best when the molar rate was 1:1(namely PU-COL-1adhesive)and the wet shear strength could reach to1.08MPa(≥0.7 MPa),which met the requirement of GB/T9846.3-2004.The solid content(38.16%)and the stability of PU-COL-1adhesive were also the optimal.The relative molecular mass of PU-COL series adhesive was obviously increased,the crystallinity was obviously reduced and the thermal stability is improved significantly after modification.The optimal conditions of hot-pressing were as follows:the temperature was 120℃,the time was 5min and the amount of adhesive was 300 g/m~2.Finally,the performance of the two adhesives obtained from this study and commercial adhesive were comparaed.The application performance of self-made adhesives and commercial adhesive were compared respectively by solid content testing,water resistance testing,XRD testing and TGA analysis.The results showed that the solid content of self-made INGE/SDS/Ep(33.42%)and PU-COL-1(38.16%)was significantly higher than commercial adhesive(21.67%).The water resistances of the self-made adhesives are better than the commercial adhesive.The results of XRD showed that the two self-made adhesives had low crystallization performance and the crystallinity was far lower than that of commercially available adhesives,which indicated that the self-made adhesives had better performance at low temperature.TG analysis results show that two self-made adhesives have good thermal stability.更多还原