| Plant fiber is a kind of high quality,natural,renewable resource,and one of the main raw materials of wood-plastic composites.Plant fiber belongs organic polymer compound.It is variety and broad,which mainly contains chitin fiber,straw fiber,wood fiber and hemp fiber and so on,and most of plant fibers as residues of production and processing are discarded or burned arbitrary.Therefore,resource utilization of plant fiber is important.Wood-Plastic Composites(WPC),plant fiber and plastic as the main raw material,is a kind of green carbon material,prepared by molding,extrusion or injection molding.It has advantages of plant fiber and plastic,widely used in landscape architecture,furniture,logistics and packaging,automotive interiors and other industries.In recent years,the problem of protection of forest resources and recovery and utilization of plant fiber has been brought into focus.Application area of WPC "instead plastic of wood" is expanding.Currently,the main raw material of WPC is wood.In order to improve the utilization of plant fibers,promote WPC species diversity,this paper selects chitin(coconut shells,hazelnut shells,walnut shells,rice husk),straw(reed straw,rice straw,wheat straw),wood(eucalyptus,poplar,pine,bamboo),11 kinds of plant fibers as the research object.The main components and performance of different plant fibers were analyzed,the mechanical,water-absorbing,thermal properties of different plant fiber composites were comparative,the effect particle size and content of eucalyptus of performance PVC-based composites were studied.The main conclusions are as follows:(1)The analysis of composition and properties of four kinds of chitin fibers:coconut shell fiber,hazelnut shell fiber,walnut shell fiber and husk fiber showed that:Cellulose and ash content of husk fiber were the highest.Hemicellulose content of hazelnut shell fiber was the highest.Lignin content of walnut shell fiber was the highest;FTIR mainly characterized cellulose,lignin,ash and other wave number segments,and absorption peak intensity had big differences at 2900?2935cm-1?1700?1735cm-1?460 cm-1;the remaining mass ratio of husk fiber,the maximum after weightlessness,was 28.47%.(2)The analysis of composition and properties of three kinds of straw fibers:reed straw fiber,wheat straw fiber and rice straw fiber showed that:tensile properties of reed stalks whose tensile strength and modulus were 54.32 MPa,3.73 GPa,was the best;cellulose,hemicellulose and lignin content of reed straw fiber was the highest,while ash content of wheat straw fiber was the highest;FTIR mainly characterized cellulose,lignin,ash and other wave number segments,and absorption peak intensity had big differences at 2230?2400cm-1?1700?1735cm-1?460 cm-1;the remaining mass ratio of wheat straw fiber,the maximum after weightlessness,was 13.29%.(3)The analysis of composition and properties of four kinds of wood fibers:eucalyptus wood fiber,pine fiber,poplar wood fiber and bamboo fiber showed that:cellulose content of bamboo fiber is the highest,hemicellulose,lignin and ash content of poplar fibers were highest;FTIR mainly characterized cellulose,lignin,ash and other wave number segments,and absorption peak intensity had differences at1700?1735cm-1?1505?1515cm-1?890?900cm-1?460 cm-1;the remaining mass ratio of poplar fiber,the maximum after weightlessness,was 25.55%;micro structure of wood fiber showed that average aspect ratio of eucalyptus fiber was the longest.(4)The analysis of the PVC based composites filled with four kinds of chitin fibers:coconut shell fiber,hazelnut shell fiber,walnut shell fiber and husk fiber showed that:the tensile strength,flexural strength,flexural modulus,impact strength and 24h water absorption of husk fiber/PVC composite were the highest,they were 23.2MPa,46.1 MPa,1.94GPa,4.66 KJ/m2and 1.75%respectively;husk fiber/PVC composite had the strongest absorption peak intensity at mainly characterized the intramolecular hydroxyl at 3300-3500cm'1 wave number segments,explain it had the strongest water absorption;two-stage weight loss starting temperature of husk fiber/PVC composite were 254.8 ?and 434.9?,the remaining mass ratio of husk fiber/PVC composite was the maximum,was 28.47%;micro structure showed husk fiber and PVC-based had the best interface compatibility.(5)The analysis of the PVC based composites filled with three kinds of straw fibers:reed straw fiber,wheat straw fiber and rice straw fiber showed that:the tensile strength,flexural strength,flexural modulus,impact strength of reed straw fiber/PVC composite were the highest,they were 36.79MPa,67.19MPa,2.08GPa,7.01KJ/m2 respectively,but it had the lowest 24h water absorption,was 1.42%;wheat straw fiber/PVC composite had the strongest absorption peak intensity at mainly characterized the intramolecular hydroxyl at 3300?3500cm-1 wave number segments,explain that it had the strongest water absorption;two-stage weight loss starting temperature of reed straw fiber/PVC composite were 247.7 ?and 435.4? respectively,the remaining mass ratio of husk fiber/PVC composite was 30.71%;micro structure showed reed straw fiber and PVC-based had the best interface compatibility.(6)The analysis of the PVC based composites filled with four kinds of wood fiber:eucalyptus wood fiber,pine fiber,poplar wood fiber and bamboo fiber showed that:the tensile strength,flexural strength,flexural modulus,impact strength of eucalyptus wood fiber/PVC composite were the highest,they were 36.94MPa,65.5MPa,2.25GPa,7.02KJ/m2 respectively,but it had the lowest 24h water absorption,was 0.94%;poplar wood fiber/PVC composite had the strongest absorption peak intensity at mainly characterized the intramolecular hydroxyl at 3300?3500cm-1 wave number segments,explain that it had the strongest water absorption;two-stage weight loss starting temperature of eucalyptus wood fiber/PVC composite were 256.4 ? and 436.8 ?respectively,the remaining mass ratio of husk fiber/PVC composite was 30.79%;micro structure showed eucalyptus wood fiber and PVC-based had the best interface compatibility.(7)The analysis of the PVC based composites filled with husk fiber,reed straw fiber,eucalyptus wood fiber showed that:The analysis of the PVC based composites filled with husk fiber,reed straw fiber,eucalyptus wood fiber showed that:the mechanical properties of reed straw fiber/PVC and eucalyptus wood fiber/PVC composite were about the same,they were higher than husk fiber/PVC composite;eucalyptus wood fiber/PVC composite had the lowest 24h water absorption;eucalyptus wood fiber/PVC composite had the highest two-stage weight loss starting temperature and larger remaining mass ratio.In summary eucalyptus wood fiber/PVC composite had the best overall performance,so eucalyptus wood fiber was the best fiber filler.(8)The analysis of PVC filled with different eucalyptus wood fiber particle size(60 mesh,80 mesh,100 mesh and 120 mesh)showed that,with the decreased of the eucalyptus wood fiber particle size,the comprehensive mechanical properties of the composites increased first and then decreased,composite with eucalyptus wood fiber particle size 100 mesh had the highest tensile strength,flexural strength,impact strength and flexural modulus,were increased 46.18%,25.04%,35.85%and 51.01%than that of the 60 mesh eucalyptus wood fiber particle size;with the decreased of the eucalyptus wood fiber particle size,the 24h water absorption of the composites increased first and then decreased,particle size 100 mesh had the lowest 24h water absorption,were reduced 51.54%than that of the 60 mesh;eucalyptus wood fiber/PVC composite with the particle size 60 mesh had the strongest absorption peak intensity at mainly characterized the intramolecular hydroxyl at 3300?3500cm-1 wave number segments,explain it had the strongest water absorption;with eucalyptus wood fiber particle size increased,the initial weight loss temperature of the number two weight loss stages was decreased;micro structure showed that with the decreased of the eucalyptus wood fiber particle sizes,two phase boundary becomed blurred,structure of the composites becomed more compacting.(9)The analysis of PVC filled with different eucalyptus wood fiber content(40wt%,50wt%,60wt%)showed that,when the eucalyptus wood fiber content increased,the tensile strength,flexural strength,flexural modulus,impact strength of the composites increased first and then decreased,composite with eucalyptus wood fiber content 50wt%had the.best comprehensive mechanical properties;the 24h water absorption of the composites increased with the eucalyptus wood fiber particle size increased,eucalyptus wood fiber content 40wt%were reduced 43.59%than that of the 60wt%;different content of eucalyptus wood fibers/PVC composites at mainly characterized-OH at 3300-3500cm-1 wave number segments had the strongest absorption peak intensity;with eucalyptus wood fiber content increased,the initial weight loss temperature of two weight loss stages were increased;micro structure showed eucalyptus wood fiber content 50wt%and PVC-based had the best interface compatibility. |
PDF Full Text Request