Abstract The mechanism analysis of the interface characteristics of sequential co-injection self-reinforced parts starts from the following three aspects. Firstly, the formation process of the bonding interface and the factors affecting the bonding strength were investigated in theory. A theoretical model of interface bonding degree, which explains the bonding degree of the interface by the penetration depth of polymer chains through the initial solid-melt interface, was proposed, and then combines the average critical penetration depth to analyze the influence of different molding parameters on the interface bonding degree. Then, the interface bonding strength of the prepared polypropylene sequential co-injection self-reinforced parts under different molding parameters (including melt temperature, mold temperature and injection speed, etc.) was studied experimentally, and the reliability of the model was verified. Finally, the interrelationship function between effective penetration degree of molecular chain diffusion and interface bonding degree on both sides of the interface is established, which provides a new theoretical basis for interfacial mechanism analysis of sequential co-injection self-reinforced parts. The results show that the interface bonding degree between experiment and theory has a good consistency, and the deviation between them is within 10%, which proves that the theoretical model is reliable. In addition, the theoretical critical penetration depth and the theoretical maximum degree of bonding sequential co-injection polypropylene products are 1.399 nm and 0.857, respectively. The performance test results of different molding parameters show that the temperature change of reinforced melt is the key factor affecting the interfacial fusion of sequential co-injection self-reinforced parts. The high temperature melt is beneficial to the diffusion and intertwining of molecular chains on both sides of the interface and to the improvement of the degree of interfacial bonding.

中文翻译：

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连续共注塑自增强件界面特性机理分析

摘要 序贯共注塑自增强件界面特性的机理分析从以下三个方面入手。首先从理论上研究了结合界面的形成过程和影响结合强度的因素。提出了一种界面结合度的理论模型，该模型用聚合物链通过初始固熔界面的渗透深度来解释界面的结合度，然后结合平均临界渗透深度来分析不同成型参数的影响关于界面结合度。然后，对制备的聚丙烯序贯共注塑自增强件在不同成型参数（包括熔体温度、模具温度和注射速度等）下的界面结合强度进行分析。)进行了实验研究，验证了模型的可靠性。最后，建立了分子链扩散的有效渗透度与界面两侧界面键合度之间的相互关系函数，为序贯共注塑自增强件的界面机理分析提供了新的理论依据。结果表明，实验与理论的界面结合度具有较好的一致性，两者之间的偏差在10%以内，证明理论模型是可靠的。此外，顺序共注射聚丙烯产品的理论临界渗透深度和理论最大粘合度分别为1.399 nm和0.857。不同成型参数的性能测试结果表明，增强熔体的温度变化是影响顺序共注塑自增强零件界面融合的关键因素。高温熔体有利于界面两侧分子链的扩散和缠绕，有利于界面结合程度的提高。