Research On Fabrication And Mechanical Properties Of Palm Fiber Reinforced Polypropylene Composites

The development of composites reinforced by natural fiber can promote the progress of related industry, environment protection and resource recycling. Palm fiber has excellent performance due to its special structure and can be directly added to the polypropylene matrix to prepare composite materials, which is very beneficial for the decrease of cost and improvement of the mechanical properties of materials. Therefore, using palm fiber in the fields of reinforced polymer composites is an innovation as for the traditional application and has a great meaning to make full use of palm resource in our country.The main content of this study includes the following five aspects:composite fabrication, palm fiber surface modification, the effect of fiber content, alignment and modification on the performance of composites.1. Composite fabrication15cm,6Wt% palm fiber was arranged in 0°of parallel equidistant between six layers of polypropylene film to form the sandwich structure, so as to fabricate composites under thermal pressure. The effect of process conditions on mechanical properties of composites was investigated by orthogonal experimental method designing by choosing pressing time, temperature and pressure as factor. Through testing and analyzing tensile strength, modulus and tear strength of composites, the optimum technical parameters of thermal pressure formation were confined as follow:10min,160℃,1.5MPa.2. Palm fiber surface modificationThe modifying method in this study is to immerse palm fiber into sodium hydroxide solution with concentrations 0%,5%,10%,15% and 20%, then use silane coupling agent (KH570) to deal with palm fiber. FTIR analysis, SEM morphology observation, thermostability, mechanical properties, diameter measurements and moisture absorption of palm fibers were investigated. Structure and nature changes were occurred to the palm fiber on modifications, which leads to decreased moisture absorption and diameter, increased erosion yield and little change in mechanical properties of palm fiber with increasing alkali concentration. The optimum thermostability was reported at 15% NaOH treatment.3. The effect of fiber content, alignment and modification on the performance of compositesDifferent content fractions 3%,6%,9% of palm fiber without surface modification were added to composites. The relationship between palm fiber content and mechanical properties of composites was studied. The mechanical performance of palm fiber reinforced polypropylene composites obtained marked improvement when compared to pure polypropylene. Tensile strength and tear strength of composites reach the maximum when fiber content is 6%. With increase in fiber content, modulus of composites increase, but ductibility and toughness of composites decrease.Three fiber's packing modes which have been used for composites at similar fiber content are as following:0°,0°/90°,±60°. An investigation on the influence of different fiber's packing modes on composites was carried out. Tensile strength and modulus give the highest value in 1 direction of±60°packing. Tear strength shows greatest enhancement in 2 direction of±60°packing. Ductibility and toughness exhibit maximum in 1 direction of 0°/90°acking.The effects of various fiber surface modifications on mechanical properties of composites at similar fiber content were investigated. Tensile strength and tear strength of palm fiber reinforced polypropylene composites are higher than those of pure polypropylene. Tensile strength, tear strength and modulus of samples increase with increasing alkali concentration. Ductibility and toughness of samples decrease with increasing alkali concentration.