Compared with traditional materials, the new fiber reinforced polymer composites have a wide range of applications in aerospace, military, defense, automotive, shipbuilding, medical equipment, sports equipment and other fields due to their light weight, high strength and excellent comprehensive performance. Polypropylene (PP), one of the five general-purpose thermoplastic resins, is second only to polyethylene and polyvinyl chloride, and has become the fastest growing general-purpose plastic. However, PP still has some shortcomings, such as high shrinkage during processing, low toughness and impact strength at low temperatures, and aging. With the continuous improvement of the comprehensive mechanical properties of materials in new application fields and occasions, the development of new high-performance polypropylene composite materials has become an important research content in this field.
α Schematic diagram of preparation of new polypropylene composites by modification of α series nucleating agent combined with glass fiber reinforcement
β Schematic diagram of the mechanism of nucleating agent regulating crystallization behavior combined with glass fiber reinforcement to enhance the adhesion between fiber and matrix resin
Inspired by the fiber reinforcement and phase transformation toughening of bio-bone replacement materials, Zhang Yagang Research Team of the Department of Resource Chemistry, Xinjiang Institute of Physics and Chemistry, Chinese Academy of Sciences creatively combined the fiber reinforced and nucleating agent to control the crystallization behavior of polypropylene. A new approach to new polypropylene composites. The method is formed by a two-step process of polypropylene, a compatibilizer, a glass fiber, a nucleating agent and an antioxidant. First, a nucleating agent is used to induce nucleation of the polypropylene, and then the glass fiber is combined with the glass fiber for further processing. The enhanced method solves the problem of directly mixing polypropylene with nucleating agent and fiber in the traditional method. Due to the introduction of glass fiber as a foreign impurity, the nucleating agent can not effectively exert its function of regulating the crystallization behavior of polypropylene. .
For the first time, the research work systematically studied the effect of different α nucleating agent and glass fiber composite system on the preparation of polypropylene composites. At the same time, the effect of nucleating agent concentration on the mechanical properties of polypropylene composites was investigated. PP achieves a tough balance alpha nucleating agent / glass fiber combination system and the best formulation. Related research results were recently published in the international journal Journal of Applied Polymer Science.
In addition, the researchers also examined for the first time the effects of glass fiber reinforced and β nucleating agent crystallization behavior on the crystallization behavior and mechanical properties of modified PP in polypropylene composites. The mechanism of the adhesion between the reinforcing fiber and the matrix resin was found to be able to compensate for the loss of the rigidity of the PP by the modification of the β nucleating agent and greatly improve its comprehensive mechanical properties. Relevant research results were recently published in the international journal Progress of the Royal Society of Chemistry (RSCAdvances).
The research result "a preparation method of polypropylene composite material" has applied for a national invention patent. This method combines the crystallization behavior of two series of nucleating agents α and β with glass fiber to form a high performance polypropylene composite material. Polypropylene composites with balanced rigidity and toughness were prepared, which provided a new idea and method for designing new polypropylene composites.