Preparation And Modification Of Polypropylene Based Composites Of Wood-plastic, Cotton- Plastic And Cotton-wood-plastic

Use wood fiber or waste cotton textile fiber with thermoplastics to prepare wood plastic composite(WPC) or cotton plastic compoite(CPC). WPC and CPC show the advantages of green environmental protection, low cost and better comprehensive performance then have a broad application prospect. However, the interfacial bonding strength and compatibility between the highly hydrophilic lignocelluloses and the highly hydrophobic thermoplastics is poor, hence it limiting the improvement of mechanical property of WPC or CPC. In this study, graphitic carbon nitride(g-C3N4)were used as reinforcing agent to prepare polypropylene(PP)-based wood plastic composite; the cotton waste textile were immersed them with reactive monomer then harden through thermal polymerization. And then used the harden cotton waste textile to prepare PP base cotton plastic composite; or mixed with wood fiber and PP to prepare cotton/wood plastic composite and then studied their structure properties.Concrete research content is as follows:1. Melamine was calcinated to prepare graphitic carbon nitride, the mixtures of g-C3N4, wood fiber, PP were extruded by using a twin screw extruder before palletized, and then the g-C3N4 reinforced PP-based WPC samples were prepared by an injection molding machine, and then observed the fractured surfaces of the sample and test the properties. The experimental results showed that part of the stacked plate-shaped g-C3N4 was delaminated under plastic shearing process, and it was packaged tightly by the PP; the WPC with 1.0wt% g-C3N4 have lower water absorption than the others; when increased the addition of g-C3N4. The flexural modules, tensile modules, water resistance and the thermal stability of the samples increased, the color of the samples were faded; the g-C3N4 have the better dispersion and comprehensive performance in the samples when the addition of g-C3N4 was3.0wt%.2. The waste textile of cotton were treated by immersed them into reactive monomer then harden through thermal polymerization. The harden cotton and PPmixture were loop through extruded and injected to prepare PP-based cotton plastic composite, the impact fracture morphology of the sample were observed and the properties were tested. The results showed that, as the addition of harden cotton textile increased, the interface between waste textile and PP became clearer, and more cavities were left in the impact fracture after the cotton was pulling out; the harden waste textile of cotton increase the flexural modules and tensile modules, thermal decomposition temperature; but increased the addition of waste textile, the flexural strength and tensile strength were increased at first then decreased, and the same as notched Izod impact strength; the sample with 10% waste textile showed the optimum comprehensive properties, but the mechanical strength of the sample with 20% waste textile were small decline compare to the 10% harden waste textile sample.3. Used the reactive monomer to harden the waste cotton textile, and then missed with pp, WF to prepare PP-based cotton/wood plastic composite,, and the impact fracture morphology of the sample were observed and the properties were tested. The research showed that, as the addition of harden waste cotton textile increased, the interface between cotton textile and PP and WF became clearer, and more cavities were left in the impact fracture after the cotton was pulling out, water absorption increased; the harden cotton textile increased the tensile modulus and flexural modulus when the addition of waste textile from 2.5% to 10% compare to the sample did not content waste cotton textile, but had no significant influence to the tensile strength and flexural strength; the sample showed the best notched Izod impact strength and comprehensive performance when added 5% waste cotton textile.