人造板用PAE改性脱脂豆粉胶黏剂的胶接固化机理研究

Facing with the application issues of soybean adhesive during the commercial production of wood composites such as poor water resistance, undesired adhesive spreading, long hot-press cycle and unstable bond properties, the wood adhesive prepared from defatted soybean flour(DSF) and polyamidoamine-epichlorohydrin(PAE) resin that has good potential to commercially produce many wood composites is selected and investigated its curing characteristics and bonding properties. Based on the characterizations using some modern analyzing techniques and wood composite evaluation, this study will systematically investigate the effects of DSF dispersibility during adhesive preparation, PAE crosslinking characteristics during hot pressing and bonding environment, respectively, on the curing and bonding of soybean adhesive. It will illuminate the relationships of dispersibility-penetrability-bonding properties, dispersibility-curing characteristics-bonding properties, bonding environment-penetrability-bonding properties, bonding environment-curing characteristics-bonding properties, by which reveal the curing and bonding mechanisms of PAE-modified DSF adhesive and obtain the effective regulation approaches on the viscosity, curing rate, initial bonding strength and stabilization of bond properties. This study will lay good theoretical foundation for dissolving the application issues of soybean adhesive during production of wood composites and, therefore, accelerate the wider application of soybean adhesive in wood composites.

主要针对大豆胶黏剂在人造板生产应用中存在的耐水性不理想、施胶困难、热压时间长、性能不稳定等问题，以有望用于不同人造板生产的PAE（聚酰胺-环氧氯丙烷）改性脱脂豆粉胶黏剂为研究对象，采用多种现代分析手段结合人造板性能评价，对PAE改性脱脂豆粉胶黏剂的固化及其对木材的胶接进行系统研究，重点探究调胶过程中脱脂豆粉的溶解分散特性、热压过程中PAE的交联特性以及胶接环境三者对大豆胶黏剂固化和胶接的影响，阐明大豆胶黏剂溶解分散特性-渗透性-胶接性能之间、溶解分散特性-固化特性-胶接性能之间、胶接环境-固化特性-胶接性能之间、以及胶接环境-渗透性-胶接性能之间的内在联系，揭示PAE改性脱脂豆粉胶黏剂的胶接固化机理，为有效调控大豆胶黏剂黏度、固化速度、人造板初始强度、胶接性能稳定化等提供理论依据，使大豆胶黏剂在人造板生产中出现的应用问题得以经济有效解决，促进无醛大豆胶黏剂在人造板生产中得到更为广泛的应用。

项目主要针对当前无醛人造板工业化生产用的PAE（聚酰胺-环氧氯丙烷）改性脱脂豆粉胶黏剂存在胶接耐水性不理想、性能不稳定、施胶困难、热压时间长等应用瓶颈问题，采用多种现代分析手段结合工艺性能与胶合性能评价，就PAE改性脱脂豆粉胶黏剂在调制、热压、胶接等过程中各组分结构转化及其对胶黏剂交联固化特性、胶合性能及工艺性能的作用机制进行系统研究。重点通过明确大豆基胶黏剂制备用脱脂豆粉和代表性PAE树脂的物化特性、脱脂豆粉在代表性PAE 溶液中的溶解分散特性、以及它们对大豆基胶黏剂交联固化特性、产物结构、胶合性能及工艺性能的影响，阐明了PAE改性脱脂豆粉胶黏剂在调制与应用过程中脱脂豆粉的溶解分散特性演变及其对胶黏剂工艺性能和胶接性能的作用规律，揭示了脱脂豆粉的溶解分散特性对PAE改性脱脂豆粉胶黏剂性能的作用机制；进一步通过明确脱脂豆粉各主要组分在调制与热压过程中与PAE树脂的交联固化反应的影响及贡献，阐明了大豆蛋白溶解分散特性-PAE交联特性-胶黏剂胶接性能之间以及热压条件-固化特性-胶接性能之间的内在联系，揭示了脱脂豆粉各组分对PAE树脂交联固化特性的作用机制；再通过明确木材抽提物、离子存在、助剂使用等各种胶接环境对PAE 改性脱脂豆粉胶黏剂渗透性、交联固化特性、交联产物结构、胶黏剂工艺性能及胶接性能的影响，阐明了胶接环境-渗透性-工艺性能之间和胶接环境-固化特性-胶接性能之间的内在联系，揭示了胶接环境对PAE 改性脱脂豆粉胶黏剂胶接固化的作用机制，最后综合分析，揭示了PAE改性脱脂豆粉胶黏剂的胶接固化机理。以此为基础，提出了降低PAE改性脱脂豆粉胶黏剂黏度、改善其交联固化速度与人造板初始强度、实现其胶接性能提升与稳定化的有效调控措施，使PAE改性脱脂豆粉胶黏剂在无醛人造板生产中出现主要应用瓶颈问题得以经济有效解决，为促进大豆基胶黏剂在无醛人造板生产中更为广泛高效应用提供了良好的理论基础。