Insights on the Molecular Behavior of Polypropylene in the Process of Ultrasonic Injection Molding

Polymers

José Manuel Mata-Padilla¹  Carlos A. Ávila-Orta²  Luis E. Elizalde²  Alan O. Sustaita³  Diego Aguilar-Viches³  Luis Marcelo Lozano³  Alex Elías-Zúñiga³  Jackeline Iturbe-Ek³ 

[1] CONACyT–Centro de Investigación en Química Aplicada, Blvd. Enrique Reyna 140, Saltillo 25294, Mexico;Centro de Investigación en Química Aplicada, Blvd. Enrique Reyna 140, Saltillo 25294, Mexico;Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Av. Eugenio Garza Sada 2501, Monterrey 64849, Mexico;

关键词: ultrasonic injection molding;    polypropylene;    product miniaturization;    molecular characterization;   

DOI  :  10.3390/polym13224010

来源: DOAJ

【 摘 要 】

Product miniaturization is a constant trend in industries that demand ever-smaller products that can be mass produced while maintaining high precision dimensions in the final pieces. Ultrasonic micro injection molding (UMIM) technology has emerged as a polymer processing technique capable of achieving the mass production of polymeric parts with micro-features, while still assuring replicability, repeatability, and high precision, contrary to the capabilities of conventional processing technologies of polymers. In this study, it is shown that the variation of parameters during the UMIM process, such as the amplitude of the ultrasound waves and the processing time, lead to significant modification on the molecular structure of the polymer. The variation of both the amplitude and processing time contribute to chain scission; however, the processing time is a more relevant factor for this effect as it is capable of achieving a greater chain scission in different areas of the same specimen. Further, the presence of polymorphism within the samples produced by UMIM is demonstrated. Similarly to conventional processes, the UMIM technique leads to some degree of chain orientation, despite the fact that it is carried out in a relatively small time and space. The results presented here aim to contribute to the optimization of the use of the UMIM process for the manufacture of polymeric micro parts.

【 授权许可】

Unknown