Exploration of thermoplastic polyimide as high temperature adhesive and understanding the interfacial chemistry using XPS, ToF-SIMS and Raman spectroscopy

• Published in: Materials & design Vol. 109; pp. 622 - 633
• Main Authors: Kadiyala, Ajay Kumar, Sharma, Mohit, Bijwe, Jayashree
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 05.11.2016
• Subjects: Design analysis; Failure; High temperature; High temperature adhesive; Interfacial chemistry; Polyimide; Polyimide resins; Raman spectroscopy; Secondary ion mass spectroscopy; Steels; Thermoplastic resins; X-ray photoelectron spectroscopy; Polyimide; High temperature adhesive; Raman spectroscopy; Interfacial chemistry
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2016.07.108

Thermoplastic semi-crystalline polyimide (PI) was explored as an adhesive for elevated temperature applications for steel to steel joint. Its lap shear strength (LSS) at temperatures 25°C, 150°C, 225°C and 300°C was evaluated and analysed. The joints showed good LSS and remarkable retention up to 225°C. The fracture mechanism was studied by scanning electron microscopy. Fractured surfaces at 25°C and 150°C showed shear elongated ductile type of failure features, while joint surface fractured at further elevated temperatures revealed weakened interface. The fractured surfaces were analysed using Micro-Raman spectroscopy (μRS), X ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectroscopy (ToF-SIMS) to understand the failure mechanism of joint. μRS results showed changes in peak positions and intensity ratios of various functional groups as a function of test temperature. [Display omitted] •Polyimide showed good retention of adhesive strength at high temperatures.•Raman spectroscopy (RS) has been utilized for detecting changes in polymeric structures as a result of stresses.•XPS and ToF-SIMs helps in understanding locus of failure in relation to test temperature.