论文部分内容阅读
利用自行设计制造的剪切拉伸双向复合应力场挤管装置生产出了双向自增强的无规共聚聚丙烯(PP-R C180)管材,研究分析了该双向应力场的剪切诱导效应对PP-R C180管材的结晶熔融、取向和拉伸强度的影响.结果表明,剪切拉伸双向复合应力场的引入所带来的剪切诱导效应促进了PP-R C180分子有序性的增加,使PP-R C180体系分子更容易形成分别沿管材周向和轴向方向的取向,因而保持甚至提高了耐热性与结晶速率,降低了结晶度,改变了PP-R C180的结晶结构与形态,诱导出了全新的β晶,进而改善了管材的强度性能.与常规管材相比,自增强管材在保持其熔点不降低的前提下,使结晶度从常规管材的44.96%降至40.03%,降低了4.93%;轴向强度从常规管材的23.35 MPa最高增强到25.49 MPa,提高了9.2%;周向强度从常规管材的22.71 MPa最高增强到26.54 MPa,提高了16.9%,且增强之后管材的周向强度已经高于了轴向强度,更优化地配置了聚合物材料的性能,更充分地满足了受内压管材使用的现实需求.
Two-way self-reinforced random copolymerization polypropylene (PP-R C180) pipe was produced by self-designed shearing tensile bidirectional composite stress field extrusion pipe. The effect of shear induction on PP -R C180 pipe.The results show that the shearing-induced effect brought by the introduction of shear stress and biaxial composite stress field can promote the orderliness of PP-R C180 molecules, PP-R C180 system molecules are easier to form along the pipe circumferential and axial orientation, thus maintaining or even increasing the heat resistance and crystallization rate, reducing the degree of crystallinity, changing the crystalline structure and morphology of PP-R C180 , Resulting in a new beta crystal, thereby improving the strength properties of the pipe.Compared with the conventional pipe, the self-reinforced pipe reduces the crystallinity from 44.96% to 40.03% of the conventional pipe while maintaining its melting point unchanged, Which decreases by 4.93%. The axial strength increases from 23.35 MPa to 25.49 MPa, and the circumferential strength increases from 22.71 MPa to 26.54 MPa. The circumferential strength increases by 16.9% The circumferential strength has been higher than Axial strength, configured to optimize the performance of more polymeric material, more fully satisfying practical needs by using the internal pressure of the pipe.