Research Of Preparation Of Enzymatic Hydrolysis Lignin/Lignocelluosic Fiber Composites

Nowadays, energy crisis and environmental pollution have become a significant barrier to human sustainable development. As cellulose ethanol industry is developing, enzymatic hydrolysis lignin (EHL) will become one of the renewable resources. Due to the molecular of the lignin is large and there are plenty of substituent groups of benzene ring, industrialized utilization of EHL has been limited. This paper discusses the properties of EHL that was obtained from the lignocellulosic ethanol production processes. It also describes the preparation technology and physical and mechanical properties of the bio-composite product.This thesis used EHL to manufacture plant fiber composite material without any synthetic resin and chemical auxiliaries and researched the manufacture technology of EHL/plant fiber composite material. And aiming at the problem of large lignin molecule and large number of substituent group, great steric hindrance and lack of activity of aromatic ring, we proposed the using of oxygen cold plasma to treat the active EHL, analyzed the influence of oxygen cold plasma treatment on the physical and mechanical property of EHL/composite material.The results of the research are showed as follows:1.The additives of EHL, hot-pressing temperature, moisture content of fiber and hot-pressing time can influence the physical and mechanical property of EHL/composite material. In this experiment scale, the better technology parameters are:10% additive amount of EHL,210℃hot-pressing temperature,20% moisture content of fiber and 90s/mm hot-pressing time.2.Response Surface Methodology(RSM)is used to research the manufacture technology of oxygen plasma EHL/composite material. In this experiment scale, the better technology parameters are:210℃hot-pressing temperature,20% moisture content of fiber and 90s/mm hot-pressing time.3.The oxygen plasma modified EHL can obviously increase the physical and mechanical property of EHL/composite material,21.8% increase of IB,41.3% decrease of TS,8.1% increase of MOR.4.The oxygen cold plasma modified EHL can obviously increase the oxygen containing functional groups on the surface, with 20%,5%,7% increase of -OH,-C=O,-O-C=O respectively. Meanwhile, the surface free radicals density of EHL was increased to a certain degree. The increase of oxygen containing functional groups and free radicals density can improve the bond strength of plant fiber.