Preparation And Properties Of Rice Husk Ash/PVC Composites

Rice is the main food crop in China.According to statistics,China’s rice output in 2019 is nearly 410 million tons.As a by-product of rice processing,rice husk is mainly generated by combustion,which will produce a lot of rice husk ash.If not handled properly,it will cause serious pollution to the environment.In addition,the problem of "white pollution" caused by waste plastics also causes certain pollution to the environment.Therefore,this paper mainly uses rice husk ash and PVC plastics as raw materials.On the one hand,rice husk ash and modified rice husk ash are used as raw materials.The properties of rice husk ash and modified rice husk ash are studied by automatic specific surface area and porosity analyzer,Fourier transform infrared spectrometer,X-ray diffraction instrument and scanning electron microscope.Finally,rice husk ash/PV is prepared by mixing rice husk ash with PVC matrix C composite.On the other hand,in order to improve the fluidity and impact properties of PVC,PP with good fluidity was used to modify PVC,and the effects of rice husk ash on the properties of PP/PVC composites were investigated.Therefore,this paper mainly studies from the following aspects:firstly,the rice husk ash and rice husk ash modified by three modifiers were analyzed,and the internal composition was analyzed by specific surface area,XRD and FTIR.Secondly,rice husk ash,modified rice husk ash and PVC were used to prepare the composites,and the mechanical properties,thermal properties and cross-section image analysis technology of the composites were explored.The effects of rice husk ash content,rice husk ash modifier types,plasticizer content and PVC modifier types on the properties of rice husk ash/PVC composites were analyzed.Finally,PP plastics were added into rice husk ash/PVC composites to explore the effects of PP content,rice husk ash content,rice husk ash modifier types and PVC modifiers on mechanical and thermal properties of rice husk ash/PP/PVC composites.Through the research,we found that:(1)The BET specific surface area of 100 mesh rice husk ash was 14.1848 m2/g.In addition,FTIR of rice husk ash showed that rice husk ash contained SiO2 and C;XRD of rice husk ash showed that the SiO2 contained in rice husk ash was amorphous.This result is consistent with the composition of rice husk ash.(2)For different contents of rice husk ash/PVC composites,the research results include:when the content of rice husk ash is 5%,the maximum bending strength of rice husk ash/PVC composite is 43.37MPa,which is 86.5%higher than that of the composites with 25%rice husk ash,while the bending modulus is 1255MPa when the rice husk ash content is 15%;for tensile properties,the bending strength of rice husk ash/PVC composite is the highest when the rice husk ash content is 15%The maximum tensile strength is 27.89MPa when the content of 5%rice husk ash is 5%,and the maximum tensile modulus is 2380 MPa when the content of rice husk ash is 15%For the impact property,the impact energy of the composite is the largest when the rice husk ash content is 5%;for the thermal weight loss performance,the thermal weight loss process of the composite consists of two stages,and the weight loss rate in these two stages decreases with the increase of rice husk ash content;for the dynamic performance,the storage modulus,loss modulus and loss modulus of the composite material are also discussed The results show that when the content of rice husk ash is 15%,the fracture fractal dimension of the composite is more complex,and the value is 1.7347.(3)For the rice husk ash/PVC Composites with different plasticizer contents,when DOP content reaches 5%,the flexural strength of the composites reaches the maximum,which increases by 13.60%compared with the composites without DOP,while the bending modulus of the composites increases first and then decreases with the increase of DOP content;as for tensile properties,the tensile strength of rice husk ash/PVC composites is the highest For the impact properties,the impact strength of rice husk ash/PVC composites increased in a certain range with the increase of DOP content;for thermal stability,the temperature of the first and second weight loss peaks increased gradually with the increase of DOP content,while the impact strength of rice husk ash/PVC composites increased with the increase of DOP content The results show that when the content of plasticizer is 15%,the structure of composite fracture is fine.(4)For the modified rice husk ash/PVC composite,the bending strength of the composite modified by titanate coupling agent is the largest,which is 6.89 MPa higher than that of the composite modified by silane coupling agent,and the bending modulus of the composite modified by titanate coupling agent is significantly higher than that of the composite modified by silane coupling agent and rare earth coupling agent The tensile strength of modified rice husk ash composite is the largest,which is 25.79MPa,which is 3.05MPa higher than that of silane coupling agent modified composite.In addition,the tensile modulus of the composite modified by titanate coupling agent is relatively high;for dynamic mechanical properties,the storage modulus of rice husk ash/PVC composite after silane coupling agent treatment is the largest,followed by titanate treatment For the fractal dimension,the fractal dimension of the composite prepared by titanate modified rice husk ash is smaller(5)For PP/PVC Composites with different PP content,when the content of PP reaches 15%,the bending strength and bending modulus of the composites reach the maximum value.Compared with the composites with 10%PP content,the bending strength and bending modulus of the composites increase by 14.18MPa and 1285MPa;for tensile properties,when the PP content is in the range of 5-15%,the tensile strength and modulus of the composite are affected by the content of PP For the impact properties,when the content of PP is 25%,the impact energy of the composites is the largest,which is 5.98kJ/m2;for the thermal properties,with the increase of PP content,the weight loss rate of the first stage gradually decreases,in addition,the temperature value of the first weight loss peak also shows a decreasing trend;for the fractal dimension,when the content of PP is 25%,the composite has the largest impact energy,which is 5.98 kJ/m2 The fractal dimension of material is the largest.(6)For the influence of rice husk ash content on the properties of PP/PVC composites,when the rice husk ash content is 15%,the bending strength and bending modulus of rice husk ash/PP/PVC composites are the largest.Compared with the PP/PVC Composites with 0%rice husk ash content,the bending strength and bending modulus of the composites increased by 29.75%and 26.85%,respectively.For the tensile properties,with the increase of rice husk ash content,the composite has the largest bending strength and bending modulus when the content of rice husk ash was 15%,the tensile strength of rice husk ash/PP/PVC composite was the highest,which was 12.31 MPa.When the content of rice husk ash was 5%,the tensile modulus of the composite was the largest,which was 41.5%higher than that of PP/PVC composite without rice husk ash.For fractal dimension,when the content of rice husk ash was 5%,the composite had the largest tensile modulus.The fractal dimension of material is the largest.(7)For the modified rice husk ash/PP/PVC composite,the bending strength and bending modulus of the composite modified by rare earth coupling agent were the largest,which increased by 2.71mpa or 10.45%compared with that of the composite modified by silane coupling agent,and the bending strength of the composite modified by titanate coupling agent increased by 1.94%compared with that of the composite modified by titanate coupling agent For the tensile properties,the tensile strength of the composite modified by rare earth coupling agent is the largest,but the tensile modulus is 1580MPa;for the thermal stability,the effect of rice husk ash modified by different modifiers is different.Among them,the first stage weight loss rate of rice husk ash composite modified by titanate was 49.87%,that of silane coupling agent modified composite was 42.34%,and that of rare earth coupling agent modified composite was 42.13%.For the weight loss rate of the second stage,there is no significant difference between silane coupling agent and rare earth coupling agent modified rice husk ash composite;for the fractal dimension,the composite prepared by titanate modified rice husk ash is the largest,which is 1.83.(8)For rice husk ash/PP/modified PVC composites,it was found that the flexural strength and impact strength of the composites prepared by DOP were 31.49 MPa and 7.96 MPa,respectively For thermal properties,the second weight loss peak temperature of DOP modified composite is significantly higher than that of CPE modified composite;for dynamic mechanical properties,the storage modulus of DOP modified composite is significantly higher than that of CPE modified composite;for fractal dimension,the fractal dimension of DOP modified composite is found The number of CPE modified composites was significantly higher than that of CPE modified composites.