The Crystalline Evolution and Mechanical Behavior of Polyamide 612 during the Stretching Process
摘要
The polyamide 612 plates were stretched at a series of temperatures to simulate the hot stretching process during the fiber spinning. The oriented polyamide 612 plates were systematically analyzed from aspects of mechanical properties, thermal properties, crystal structure and crystal morphology. The experimental results show that spherulites are destroyed and evolved into oriented fibrilsduring tensile process. The mechanical properties of polyamide 612 are greatly inhanced after pre-stretching process. There exists a crystal phase transition behavior in polyamide matrix (from γ to α-formcrystals), which is induced by arrangment of hydrogen bonds. The maximum tensile strength of polyamide 612 appeares at 120 °C, which is result of competition of chain orientation and relaxation. This works can povide theory support for preparation of polyamide fibers with high performance.