Contains β-nucleating Agent Of BOPP Crystallization And Mechanical Behavior Research

BOPP (Biaxial oriented polypropylene film) has been applied in many fields, including agriculture, packaging service, food safety and so on. Its comprehensive performance is very excellent, however the toughness and thermal deformation is poor, limiting its industrial applications. The crystallization behavior and mechanical property of Biaxial oriented iPP/WBG Ⅱ film were studied in this paper. The Key is to improve the crystal structure and morphology of BOPP, besides the mechanical property was observed to achieve the goal of toughening.The iPP/WBG Ⅱ BOPP samples have been prepared by homogenizer, Hakee polymer processing workstation, and Preparation thickness uniformity of polymer film different process parameters was selected. Then the effects of processing condition and the content of nucleating agent and character of BOPP crystalline orientation mechanical properties of influence were discussed. The effects of contents of WBG Ⅱ on the crystallization behavior and mechanical properties were also observed in this paper. It is founded that it is very difficult to form β-crystal form in pure BOPP. The crystallinity of BOPP films which contain nuclear agent increase from66.5%to78.8%with extrusion rate increasing from12r/min to50r/min, at the same time, increasesed by Half peak width, decreased by the size of the crystal. Due to the faster tensile rate, the molecular of iPP was more ordered. Chain conformational entropy decrease, then obvious molecule chain orientation, leading to the high crystalline property. The orientation of BOPP samples are increasing with the tensile rate, the degree of orientation is increased from0.141to0.470with tensile rate of change. Besides, the orientation is very sensitive to the mold temperature, the degree of orientation decreases from0.911to0.477with temperature increasing from190to230℃.The results show that the tensile strength increase with tensile rate, while the breakage elongation do the reverse. Besides, the contents of WBG Ⅱ have less influence on the tensile strength, while the breakage elongation along two direction increase from from158.4%and139.3%to287.9%and287.9%, respectively.WBGⅡ is an efficient β nucleation agent, which can induce P-crystal within BOPP. The results indicate that the crystallization is enhanced in BOPP with the contents of WBG Ⅱ increasing, and the cystallinity is affected by high tensile rate significantly. Combining static crystallization and stretching process, stretching rate too quickly for XC and Φβ value influence. According the DSC and POM results, it is founded that the spherulite sizes of BOPP sample which annealed under145℃are larger than that of the virgin ones. The melt point of β-crystal increased to150.1℃in annealed samples. Besides the WAXD results indicate that the peak width at half height of β-crystal in annealed samples narrows, suggesting a more perfect spherulite structure.In this paper, we studied the effects of nucleating agent and processing condition on the crystallization behavior of BOPP. The results indicate that compared to processing condition, the nuceating agents can adjust the crystalline and mechanical properties more efficiently, But not the appropriate processing parameters could inhibit the crystallization behavior of BOPP.