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Design and Performance Evaluation of Coir Toughened Composite

Author: YaoJia
Tutor: HuYingCheng
School: Northeast Forestry University
Course: Wood Science and Technology
Keywords: Coir Impact toughness Wood replacement material Reinforced body form Mechanics performance model
CLC: TQ352
Type: PhD thesis
Year: 2013
Downloads: 195
Quote: 0
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Abstract

Making advantages of coir as the key point, making the reasonable effective use of coir in composite industry as the main research contents, also making design theory of composites as the guide, different types of coir composites have been designed and the usage of coir advantages has been realized. Various performance testings of coir composites have been done by the combination of experiment and theory, electron microscope analysis (SEM), energy spectrum analysis and dynamic mechanics performance analysis (DMA) and other modern observation and testing means have been adopted, accurate analysis of material properties have been obtained, and the design of coir toughened composites has been realized.The research contents are divided into five parts, first of all, the advantage of coir fibre has been studied, the characteristics of internal pore structure and low density decide the function characteristics of sound absorption and heat preservation; the bigger microfibril angle and the higher breaking elongation are the advantage characteristics of coir, so coir fibre toughening design has been focused on in the material design. The production process of coir density board has been optimized, and the sound absorption and insulation performance has been researched. Wood replacement materials with coir sandwich structure have been designed, making different types of adhesive and different glass fiber reinforced forms as reasearch factors, realize the design of the sandwich wood replacement materials, coir sandwich structure material with high impact toughness and comprehensive mechanical properties have been obtained. Performance evaluation and research of coir reinforced unsaturated polyester with different reinforced forms have been done, the influence law on the mechanical performance index of coir mat, coir net and coir rope has been compared, the toughening design of this three reinforced forms of unsaturated polyester matrix have been realized; Based on the mixture law of composites, the mechanical model establishment and evaluation of coir rope reinforced composite have been realized.The main innovation results are as follows:(1) The microfibril angle of coir has been reasonable determined, the mechanical performance indexes have been clarified, fracture characteristics influence of coir microfibril structure has also been clarified. So as to the advantages of high fiber fracture toughness have been determined as the starting point.(2) The process optimization design of coir fibre low density board has been done, and sound absorption and heat insulation advantages have been verified, structure design of variable density gradient coir sound absorption board has been put forward, the rational utilization foundation of coir composites in building materials has been laid. (3) In the wood replacement materials design part, through a further reinforced design of sandwich structure, namely to joining glass fiber reinforced body and using isocyanate as adhesive, the overall performance optimization design of "wood veneer panel+the core layer of coir mats+glass fiber mesh cloth+wood veneer panel" composite has been realized. The mechanical properties, especially the impact toughness of this kind of composite can excess natural cathay poplar, reasonable design of a wood replacement material can be realized.(4) The material design of coir reinforced unsaturated polyester have been done, three different coir reinforced body forms:coir mat, coir net and coir rope, because internal structure and the difference fiber direction, performance differences of different forms of coir reinforced unsaturated polyester material have been determined, the comparative study of mechanical properties of three reinforced forms composites has been done, the best impact toughness obtained from coir rope reinforced body has been confirmed.(5) Through the structure analysis and the mechanical properties of coir rope reinforced composite, the tensile modulus prediction of coir rope reinforced composite based on the composite mixed law has been established, the toughening mechanism theoretical models of different body forms of coir fiber toughened unsaturated polyester has been bulit, the tensile properties model has been established and the natural fiber composite performance prediction system has been perfected.Through the research in this paper, the toughening advantages usage of coir has been improved, the variable density board absorption structure, wood replacement materials of coir sandwich and the coir toughened unsaturated polyester materials all have good application value. A variety of options can be offered for the coir resources reasonably usage. In addition, through the establishment of the mechanics performance prediction model of coir fiber reinforced unsaturated polyester, an effective method for the mechanical properties of composite evaluation system has been provided.

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