Preparation of Carbon Fiber–Reinforced Polymer Using Oxidatively Degradable Matrix Polymer: Recovery and Reuse of Carbon Fiber Sheet

Journal of Applied Polymer Science, Journal Year: 2025, Volume and Issue: unknown

Published: March 13, 2025

ABSTRACT Carbon fiber–reinforced polymer (CFRP) was prepared from carbon fiber (CF) sheet with a diacylhydrazine‐crosslinked matrix polymer, which is stable to natural stimuli, including heat and oxygen, but rapidly decrosslinks dissolves when treated sodium hypochlorite solution. The CF recovered without damage the CFRP plate solution shearing force. could be used directly prepare next CFRP, again any damage. Because high durability stability are compatible present repetitive use of for practicable.

Language: Английский

Process simulation of laser shock-based disassembly of adhesively bonded composite/metallic structural parts: a numerical upscaling

The Journal of Adhesion, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 24

Published: July 8, 2024

In previous works, both experimental and numerical investigations have shown the potential of laser shock technique for disassembling adhesively bonded composite/metal coupons. This study extends this concept to upscale method, focusing on full disassembly a foreign object damage (FOD) panel designed replicate an aircraft engine fan blade. Utilizing LS-Dyna explicit FE software, simulation incorporates various material models: progressive model 3D CFRP substrate, Johnson–Cook plasticity combined with Grüneisen equation state titanium layer, cohesive zone bilinear traction separation law adhesive layer. Investigating FOD panel's inclined geometry, preliminary analysis examines impact inclination angles wave propagation back face velocity, revealing minimal alterations. Initial simulations are conducted determine double pulse delay times evaluate spot location effects. Automation multi-step process is achieved through Python script. After approximately 30 shots, complete strip achieved, observed primarily limited matrix cracking in composite substrate. Numerical findings support efficacy double-shot method metallic/CFRP components, contingent upon appropriate arrangements.

Language: Английский

Reactive Modified Epoxy Resin and Its Miscible Blends Based on Recycled Oligomers from Solvolysis

ACS Applied Polymer Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 26, 2024

Chemical depolymerization of fully cured epoxy resin with 20% reactive modifier was successfully performed via a solvent-assisted solvolysis process into low molecular weight recyclable oligomers (RO) at 240 °C in pressure vessel 650 psi for 4 h. The thermoset depolymerized transparent brown viscous fluid higher viscosity than the uncured approximately 93% yield. Different concentrations RO were homogeneously mixed pure resin, and their curing kinetics, viscosity, FTIR, mechanical properties, DMA, cross-link density investigated. kinetics modified (baseline) its mixtures different investigated under both isothermal nonisothermal conditions using small amplitude oscillatory shear flow. elastic moduli (G′ G″), complex (η*), tan δ values evaluated times temperatures. G′, G″, η* increased dramatically, while decreased strongly by several orders magnitude gel point. zero-shear (η0) determined from angular frequency dependent on based Cross model blend compositions liquid state before curing. composition dependence η0 showed positive deviation linear mixing rule well described Lecyar model. apparent activation energy (Ea) also according to Arrhenius equation found be 46 ± 2 kJ/mol regardless contents RO. For all blends up 40 wt % RO, only one peak systematically shifting lower temperatures increasing content observed DMA measurements, indicating that are miscible

Language: Английский