Study On Cotton Stalk Bast Fibers Reinforced PLA Automobile Interior Lining Board

The development of automobile interior materials is changing with each passing day in modern society. Traditional automobile interior lining board is heavy and low strength, so some new light and green materials with low cost are born. Composites which are lightweight and high strength are the mainstream materials in the propulsion process of automobile lightweight technology.This paper recycled waste cotton stalks bast and made them become fibers after degumming, then mixed with PLA. According to the composites application, making cotton stalks bast fibers reinforced PLA automobile interior lining board with flame-retardant and heat-resistant factions.Firstly, this paper used intumescent flame retardant (IFR) system which was APP/PER to modify the flame-retardant property. The APP as acid source, PER as carbon source and cotton stalks bast fibers reinforced PLA formed IFR system, then reducing the density of oxygen, becoming protective layer, thereby stopping the combustion. At the same time, TAIC was also added to modify the heat-resistance of the material in the experiment. Adding TAIC could improve the crystallization property and come into cross-linking structure in the condition of high temperature, reach the results which strengthen the heat-resistant property.Secondly, orthogonal experiment of L16(45) was done according to the length of cotton stalks bast fibers, mass fraction of fibers, molding temperature, addition of APP/PER and addition of TAIC. After finishing the experiment, the mechanical properties (tensile strength, flexural strength and impact strength), flame-retardant property and heat-resistant property were tested, then the response surface analysis of heat-resistance was also done. The results showed that mass fraction of fibers, addition of APP/PER and TAIC had a great effect on the properties of the materials. Meanwhile, the optimal compounding process for making the cotton stalks bast fibers reinforced PLA automobile interior lining board was that length of fibers was 10mm, mass fraction of fibers was 26.7%, molding temperature was 175℃, addition of flame-retardants was 8% and addition of TAIC was 2.1%. Then its tensile strength was 45.381 MPa, flexural strength was 58.572 MPa, impact strength was 10.95J/CM2, LOI was 28.37 and the HDT was 162.14℃. Finally, the fogging property was tested especially. Fogging of the board was 1,28mg (<2mg) when using the optimal compounding process to make this board. It could meet the fogging requirements and then be applied in automobile interior materials.This paper not only reused the waste (cotton stalks bast), turned it into treasure, but also made a kind of new automobile interior lining board which was lightweight, environmental and biodegradable. Making cotton stalks bast fibers reinforced PLA automobile interior lining board reduced production costs and corresponded to the requirement of sustainable development. It has great economic value and social value.