改性红麻纤维/棕榈油基树脂复合材料的协同制备及其界面结合机制

目前纤维增强树脂基复合材料中大量使用石油基热固性树脂，不符合可持续与绿色发展的理念。鉴于此，本项目拟采用棕榈油为原料合成环境友好、低成本、低粘度的棕榈油基热固性树脂，并以红麻纤维为增强体制备高生物基含量的“绿色”复合材料。针对棕榈油低不饱和度的本质特性而导致的树脂交联度低、力学性能差等关键问题，利用醇与甘油三酯的转酯化反应合成棕榈油基单甘酯，再引入刚性单体制备棕榈油基树脂，揭示新型棕榈油基树脂的合成机制、化学成分、化学流变性和固化动力学机理。针对红麻纤维与树脂基体的界面相容性难题，利用甘油三酯与纤维表面羟基的转酯化反应，将棕榈油脂肪酸链接枝到纤维表面。通过对改性红麻纤维/棕榈油基树脂复合材料的制备及表征，探究新型树脂与红麻纤维在复合过程中的界面结合机理，阐释树脂基体与纤维改性协同增强复合材料力学性能的机制，为环境友好、高强度植物纤维增强生物基树脂复合材料的制备和应用提供科学依据。

The large consumption of petroleum-based thermosetting resins in fiber-reinforced composites cannot meet the requirement of green and sustainable developments. The proposal aims at developing environmentally friendly palm oil-based thermosetting resins with low-costs and low-viscosity, and then the resulting resins will be used as the matrices for kenaf fibers to prepare the green bio-composites with high renewable contents. The palm oil-based resins will be synthesized through transesterification of triglycerides with alcohols and incorporation of rigid structures, which provides the solution for the problems including low crosslinking density and poor mechanical properties of the palm oil-based resins due to the intrinsic drawbacks of palm oil, i.e., low level of unsaturation. The synthesis mechanism, chemical compositions, rheological property, and curing kinetics of the new resins will be fully investigated. Kenaf fibers will be modified with palm oil through the transesterification between the hydroxyl groups of fibers and triglycerides, which induces the grafting of palm oil-based fatty acid on the fiber surface and hence increases the interfacial adhesion between fibers and matrices. The bio-composites from the modified kenaf fibers and palm oil-based thermosets will be prepared. The interfacial adhesion between the fibers and the new resins, and synergistic reinforcing effects of fiber modification and resins on mechanical properties of the kenaf fibers-reinforced palm oil-based resin composites will be studied in details. The research enables us to gain a good understanding of mechanism for the preparation and application of environmentally friendly composites from natural fibers and bio-based resins.