Plastic rod as a promising feed material for enhanced performance of ultrasonic plasticization microinjection molding: Plasticization rate, mechanical and thermal properties

• Published in: Polymer testing Vol. 118; p. 107909
• Main Authors: Wu, Wangqing, Pan, Lida, Li, Binbin, He, Xiansong, Jiang, Bingyan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2023; Elsevier
• Subjects: Mechanical properties; Plasticization rate; PP rods; Thermal properties; Ultrasonic plasticization; Thermal properties; Mechanical properties; Ultrasonic plasticization; PP rods; Plasticization rate
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2022.107909

A polymer plasticization rate measurement method is proposed for ultrasonic plasticization microinjection molding. The effect of ultrasonic amplitude on the plasticization rate of polypropylene (PP) rods was comprehensively investigated, and the mechanical and thermal properties of PP rods were studied using tensile tests, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Results show that the plasticization rate of PP rods increased from 67.25 mg/s to 192.41 mg/s with increase of ultrasonic amplitude, an increase of 186%. The mechanical properties of the PP samples remained stable under different ultrasonic amplitudes, with tensile strength around 21 MPa and elongation at break about 21%. DSC and TGA results showed that PP samples exhibit improved thermal properties after ultrasonic plasticization compared with pure PP. The melting point of the PP sample decreased from 171.7 °C to 164.0 °C and the crystallinity increased from 26.1% to 38.7%. The temperatures corresponding to 1% and 5% weight loss of PP increased from 283.63 °C to 350.30 °C without ultrasonic amplitude to 393.70 °C and 420.13 °C, respectively. The studies have great significance to further understand the influence of ultrasonic plasticization process parameters on the plasticization rate and material properties of polymers. •A simple real-time method for measuring polymer plasticization rate is presented.•The plasticization rate can be significantly increased with increasing ultrasonic amplitude.•The properties of the parts is not undermined while the molding process is more efficient with increasing ultrasonic amplitude.