Preparation Of Fir Powder Modified With Benzyl Chloride, Octadecanoyl Chloride And Their Effects On The Mechanical Properties Of PP Composites

In this thesis,fir powder was modified in two ways,and the mechanical properties of the modified fir powder/PP composites were studied.Main research contents are as follows:Firstly,fir powder with the size of about 200 mesh was treated with 8%NaOH solution and acetone respectively.The structure and properties of the treated fir powder were analyzed by FT-IR,XRD,TG and SEM.The results showed that after treatment, there was no vibration absorption peak of the carbonyl bonds at 1732cm-1,which means that the small molecule compounds containing carbonyl groups in the fir powder were dissolved;The crystal structure of lignocelluloses and the hydrogen-bonds were broken partly,the ratio of remaining carbon of treated fir powder was about 26% at the temperature of 500℃;the relative crystallinity of fir powder was lower after treated with NaOH solution.Secondly,modified fir powder were prepared by the benzylation reaction of fir powder and benzyl chloride with toluene as solvent and NaOH as catalyst.The influences of the process conditions on WPG of modified fir powder were studied.The structure and properties of the modified fir powder were analyzed by FT-IR,XRD,TG,DSC and SEM,the absorbent properties of benzyl chloride modified fir powder on water, ethanol, N, N-dimethylform amide(DMF),trichloromethane,n-hexane were studied.The crystal structure of fir powder were broken after modification,the ratio of remaining carbon of modified fir powder was about 20% at the temperature of 500℃;The absorbent capacity of modified fir powder decreased while the WPG increased.Thirdly,the influences of reaction conditions with or without pyridines on WPG of octadecanoyl chloride modified fir powder were discussed,where DMF was used as solution.Furthermore,we studied the influences of the process conditions on WPG of modified fir powder when pyridine was used as catalyst and acid absorbent.The structure and properties of the modified fir powder were analyzed by FT-IR,XRD and TG.The absorbent properties of octadecanoyl chloride modified fir powder on water,ethanol,DMF,trichloromethane,n-hexane were studied.The crystal structure of fir powder were broken after modification,the ratio of remaining carbon of modified fir powder was about 17% at the temperature of 500℃.The solution absorbent capacity of octadecanoyl chloride modified fir powder was similar to the benzylated fir powder.At last,two types of modified fir powder/PP composites were prepared by mixing the modified fir powder and PP with twin-roll mill.The influences of WPG and content of modified fir powder on the mechanical properties of composites were studied,and the impact fracture surface of composites was characterized by SEM.Benzylated fir powder/PP composites have the highest impact strength under the condition of 50% WPG and 10% content of modified fir powder,while octadecanoyl chloride modified fir powder/PP composites have better mechanical properties when WPG was 55% and the content of modified fir powder was 10%.