Synthesis And Characterization Of Low Protein Natural Rubber Latex Foam Materials

The natural rubber latex products could be divided into four categories,and the natural rubber latex foam(NRLF)in this paper is one kind of the products.The porous structure of natural rubber latex foam provided the materials with the advantages of low density,high elasticity,high buffering,sound and shock insulation,thermal insulation and so on.At present,the commercial products of natural rubber latex foam mainly include natural rubber latex mattress,natural rubber latex pillow,etc.In recent years,the laboratory research on natural rubber latex foam has focused on Dunlop method to modify the natural rubber latex foam with fillers.The purpose of this project is to improve the performance of natural rubber latex foam based on the preparation of pure natural rubber latex foam by Dunlop method.The specific experimental results include:(1)using high ammonia natural rubber latex as raw material,pure natural rubber latex foam was prepared by Dunlop method.The density of foam sample is 85.4 kg/m3,the tensile strength is 0.174 MPa,and the compressive strength is 0.014 MPa.The pure natural rubber latex foam has high porosity,softness and pressure resistance.(2)The low protein natural rubber latex foam was prepared by protease enzymolysis and multiple centrifugation.The nitrogen content can be reduced from 0.44%to 0.32%,which was helpful to reduce the allergenicity of natural rubber latex foam and improve the peculiar smell of protein in the heating process of natural rubber latex foam.(3)Chitin was selected as natural antibacterial agent to prepare antibacterial latex foam composite by mixed filling.When 3 phr chitin was added,the antibacterial activity of antibacterial latex foam was twice as high as that of natural latex foam,and the antibacterial activity of antibacterial latex foam filled with 5 phr chitin was increased to 281.3%,avoiding the possibility of microorganism breeding in the bedding fabric.The innovation of this paper is that low protein natural rubber latex is used for the preparation of natural rubber latex foam for the first time,and natural polymer chitin is used as an antibacterial agent and mixed with natural rubber latex to prepare antibacterial natural rubber latex foam for the first time.It provides a new idea and direction for the follow-up development of natural rubber latex sponge products with low allergenicity and environmental protection.