Preparation And Characterization Of Natural Latex Form Composites

Natural latex is a kind of biosynthesis liquid, and it is characterized by excellent comprehensive performance, good film-forming, and easy to cure. So it is an important elastic material. Natural latex foam material obtained by natural latex has long been used in the field of interior decoration, sporting goods, furniture, automotive, packaging etc. However, natural latex foam material also has many disadvantages, such as complex production process, low mechanical strength, non-renewable raw materials, etc. Therefore, green, lightweight, composite are the developmental trend of natural latex foam.In this dissertation, firstly, natural latex foam material was prepared by natural latex, N,N’-dinitroso pentamethylene tetramine (foaming agent H), and urea. Activation mechanism of foaming agent H with urea in natural latex matrix was qualitatively and quantitatively characterized by TGA and FTIR analysis, and their effects on the foaming performance for natural latex foam material were also investigated. The results show that the decomposition mechanism of foaming agent H and urea mixture is different from their own decomposition reactions, they react at a temperature range from130℃to180℃, and the peak decomposition temperature is140℃.The optimum ratio for the two compounds is at their equivalent weight. The density and foaming rate of natural latex foam material are affected by blowing agent content and conditions. When the foaming agent content is3%, the foaming temperature is140℃, and foaming time is1.5h, natural latex foam material show lower density (0.30g/cm3) and higher foaming rate (4rate). Secondly, sugarcane rind fiber/natural latex foam composites were prepared by natural latex and sugarcane rind fiber. In order to improve the interfacial adhesion between sugarcane rind fiber and natural latex matrix, three kinds of chemical solvents including acrylic acid (AA), sodium hydroxide (NaOH) and silicon coupling agent (KH550) were selected and one-step or two-step treatment method were used. When one-step method handle, the effect of KH550was best, NaOH takes second place, effect of AA handling was not large. Compared with the one step method handling, two-step method handling had synergism effect, and showed higher tensile strength and elongation at break. For tensile strength and elongation at break, the effect of KH550and NaOH was best, AA and KH550takes second place, the effect of A A and NaOH was not large.In this dissertation, finally, rubber/natural latex foam composites were prepared by natural latex and rubber. The microstructure, density, mechanical property, snapping back rate, compressive strength and thermal property of composite were characterized by SEM, TGA and tensile strength measurement. When the particle size of the rubber is60mesh, and filling content of the rubber is30%, rubber/natural latex foam composites show highest snapping back rate (91.2%), highest compressive strength (18.9MPa), lowest compression set (10.5%). The rubber improved the elasticity of its composites.