Experimental and numerical investigations on microstructures and mechanical properties of hybrid fiber reinforced thermoplastic polymer. (September 2018)

• Record Type: Journal Article
• Authors: Wang, Qian; Sun, Lingyu; Li, Lijun; Yang, Wu; Zhang, Yiben; Dai, Zongmiao; Xiong, Zhenkai
• Is Part Of: Polymer testing. Volume 70(2018)
• Page Start: 215
• Page End: 225
• Publication Date: 2018-09
• Subjects: Thermoplastic polymer -- Nano-indentation test -- Hybrid materials -- Molecular dynamics -- Microstructures -- Interface; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2018.07.010
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: Organic sheet overmolding injection (OSOI) is an integrated manufacturing process in which thermoplastics or composites are injected directly on the back of thermoformed organic sheets. It is one of the most promising processes to obtain lightweight structures with excellent mechanical properties and complex geometry. Microstructures, mechanical properties and bonding mechanisms of the interface between injection and thermoformed composites were investigated using SEM analysis, nano-indentation tests and molecular dynamics simulation, because the interface may be the weakest layer due to the pores, inclusions and thermal-expansion coefficient mismatch. SEM results show that the interface microstructures can be categorized into three kinds of features, that are wavy, bubble, and diffusion configurations, respectively, and they are greatly influenced by the preheating temperature of laminates. By appropriate preheating, the equivalent interface elastic modulus increases approximately 2.3 times. Moreover, the bonding mechanisms of the interface of preheated specimen include micro/nano scale mechanical interlocks, diffusion reaction, Van der Waals force and electrostatic interaction. This research could serve as a foundation for the application of hybrid fiber reinforced thermoplastic polymer. Highlights: Microstructures and properties of hybrid fiber reinforced thermoplastic were studied using SEM and nano-indentation tests. Three typical kinds of interfacial microstructures, namely, wavy, bubble and diffusion configurations are found. The contribution of preheating thermo-stamped polymer composites to interface bonding strength was revealed. A molecular dynamics method to predict interface modulus of hybrid fiber reinforced thermoplastic is proposed and validated. The interface bonding included micro-mechanical interlocks, diffusion reaction, Van der Waals and electrostatic interaction.