| By controlling the structural form of the material through self-reinforcement,the mechanical properties of the composites can be improved,and the density of the composites can also be reduced.This method has the same effect as the forming method that introduces the reinforcing phase,but the self-reinforced material is derived from the material itself,and no other substances are added during the molding process.Therefore,the compatibility between the reinforcing phase and the matrix phase is very good.There are no shortcomings such as poor interface bonding with external reinforcement,and at the same time there is no problem of material recycling,which is very in line with the current social needs of sustainable development.By researching the self-reinforced composite material molding device and mechanism,it has better lightness and high strength,and meets the wide application of various fields of the national economy.It has important theoretical research significance and industrial application value.In this paper,based on polypropylene filled with inorganic substances,a new type of solid-state tensile self-reinforcement experimental platform is built.Based on this experimental platform,inorganic fillers with excellent mechanical properties and heat resistance are successfully prepared polypropylene self-reinforced composites;study and analyze the mechanical properties,thermal properties,micro structure and density of solid-stretched self-reinforced composites under different inorganic content and different stretching process conditions,and the process parameters and composites properties are explored connection.The main work contents are as follows:1.Adopt the modular design of each component of the solid-state streching device,analyze and determine the use of carbon fiber infrared heating tube to heat the blank profile and design the solid-state drawing die with an appropriate draw ratio,and build a solid-state drawing self-reinforcement experimental platdorm.2.Choose calcium carbonate and talc powder content of 30%,35%,40%,45%,filled polypropylene,melt extrution granulation and molding 18mm×12mm polypropylene filled composite material blank profile;The process parameters of the drawing temperature and drawing speed in solid state drawing were determined for experimental study;3.Under the given stretching speed of 2.0m/min and stretching temperature of 140?,the mechanical properties,heat resistance and density of Talc/PP and CaCO3/PP composites after stretching were studied with different inorganic substances and contents And the influence of micro structure:After the inorganic content is increased from 30%to 45%,the mechanical properties of the composite material before and after solid state drawing gradually decrease and the density gradually increases,and the Vicat softening point of the composite material after solid state drawing increases with the increase of the inorganic content.SEM photos show that after solid state stretching,the molecular chains in the Talc/PP and CaCO3/PP self-reinforced composites are highly aligned,and a fiber bundle with a fibrous structure is generated;4.Select a group of formulas with the largest density reduction as the basis,the given stretching temperature is 140?;By changing the drawing speed process conditions,the effects of different drawing speeds on the thermal properties,density,mechanical properties and micro structure of polypropylene self-reinforced composites were explored;The given stretching speed is 2.0m/min;By changing the drawing temperature process conditions,explore the effects of different drawing temperatures on the thermal properties,density,mechanical properties and micro structure of polypropylene self-reinforced composites;5.Preliminary research on the compound filled polypropylene of talc powder and magnesium carbonate,the preparation of(Talc+MgCO3)/PP solid tensile self-reinforced composite material with different magnesium carbonate content,and analysis of its mechanical properties and density influences. |
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