| Wood-plastic composites is an environment-friendly new materials, which is processed by natural plant stalks and PVC as raw materials with some processing aids, has been rapid development in recent years, and the wood-flour/PVC composites is the most widely used in those composites. This article is the use of cotton stalks flour as raw materials preparation of composite. The research process, including processing technology, improve compatibility and the practical application, with the purpose of get a cotton stalks-flour/PVC composites, which is a new way for the comprehensive utilization of agricultural waste cotton stalks. With the large number of experiments, the conclusion is as follows:1. The process of production was optimized by response surface methodology (RSM) to obtain the optimum conditions. It was indicated that the optimum condition was as follows: Temperature,166℃; Pressure,25MPa; Time,127s. The regression equation describing process of production was obtained by response surface methodology:Y= 42.53+1.63X1+ 4X2+0.45X3-5.63X12-6.46X22-1.62X32-0.62X1X2-1.1X1X3-0.82X2X3.2. Different content(20/10,30/100,40/100,50/100; cotton stalks-flour/PVC) and different particle size(60 mesh,100 mesh,120 mesh,150 mesh) as filler, which were prepared for preparation of composites, and tensile strength, elongation at break, flexural strength of composites were tested. The results show that the optimum amount of cotton stalks-flour was 40phr, and particle size was 100m.3. Coupling agent treatment, alkali treatment and graft copolymerization of three different surface treatments were used in cotton stalks-flour; the results showed that the three processing methods can improve compatibility and mechanical properties of composites, Improvement of graft copolymer of which the most obvious effect, coupling the second. The best dosage of silane coupling agent is 2%, the best concentration of alkali solution is 15%, in the graft copolymerization reaction, the initiator concentration of 0.004mol/L, show a high grafting percentage and grafting efficiency.Explored three different coupling agent (Al ester, titanate and silane) surface modification effect, which were used to preparation of composites, flexural strength and elastic modulus of cotton stalks-flour/PVC composites were tested. The results show that the silane coupling agent compared with the other two had the better modification effect, the compatibility of cotton stalks-flour and PVC has improved significantly.Fracture surface and surface morphology of cotton stalks-flour/PVC composites were observed by SEM, which confirmed the positive role of modification, the emergence of characteristic peaks of cotton stalks-flour by FTIR also confirmed that has been successfully modified.4. With orthogonal experiments, the amounts of the main additives were discussed; the results show primary and secondary factors that affect the flexural strength was as follows: SA>ACR> CaSt2> CaCO3, ultimately determine the optimum dosage of additives as:stearic acid 0.3phr, ACR 8phr, CaCO3 10phr, CaSt2 0.5phr.5. Low foaming cotton stalks-flour/PVC composites was prepared, through testing and analysis the density, mechanical properties and rheological properties of that, It was indicated that AC:ZB-530 is 1:5 (AC lphr), CPE content of 6%, DOP, the amount of stearic acid and paraffin were 2phr,0.3phr and 0.4phr, the composite material exhibits excellent overall performance.6. With the research on Applications of cotton stalks-flour/PVC composites (weather resistance), through water absorption test, mechanical property test, vicat softening point test and heat resistance test, the results show that the cotton stalks-flour/PVC composite have great practical value, which can be applied to industrial production and that is a new way for comprehensive utilization of resources on agricultural waste straw. |
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