Enhancement of Mechanical Integrity of Advanced Composites using PMAA-Electropolymerised CF Fabrics

Abstract

The aim of the present study is the development of new composite materials that show improved mechanical and structural integrity. In order to accomplish this goal, a novel functionalization method of the carbon fibers for the reinforcement of the composites surface was investigated. Through the electrografting of methacrylic acid onto the surface of the carbon fiber, this treatment aims to selectively modify the surface of the carbon fabrics, in order to create active groups that can chemically react with the epoxy resin, under heat and pressure. By this way, better adhesion as mechanical interlocking between the resin and the reinforcement can be achieved. The surface treatment was examined qualitatively by means of Infrared spectroscopy, Scanning Electron Microscopy and Raman spectroscopy. The carbon fiber reinforced polymers were manufactured via the hot-press technique and they were subsequently submitted to flexural, shear and nanoindentation test. Finally, the internal structural integrity was tested through micro-Computing Tomography.

Enhanced properties of PAN‐derived carbon fibres and resulting composites by active screen plasma surface functionalisation

“…Extensive research has been conducted on the physico‐chemical interaction between CFs and the matrix, [ 4–6 ] and a range of surface‐engineering methods have been studied with the aim to enhance CF/substrate interfacial strength, such as chemical/electrochemical oxidation, plasma treatment, polymer grafting, sizing and nanoparticle coating. [ 3,7–12 ] All these techniques aim to modify the surface morphology of CFs, to introduce new chemical groups to the CF surface, and to change the surface free energy and hence improve the CF/matrix interfacial bonding. For instance, chemical oxidation generally etches the fibre surface and implants carbonyl and hydroxyl groups on the fibre surface, resulting in better bonding.…”

Prospects in the application of a frontally curable epoxy resin for cured‐in‐place‐pipe rehabilitation

“…Whereas, the peak centered at 810 cm −1 corresponding to acrylate double bond stretch was used for measuring conversion in TLC* resin 36 . The peak at 1509 cm −1 corresponds to saturated CC carbon stretch in the aromatic ring present in polyvinyl ester and is therefore used as the nonreactive reference peak for conversion calculation in TRC* and TLC* resins 43,47 . The monomer conversions for TRC* and TLC* resins were calculated and be 63% and 67%, respectively.…”

“…The characteristic peaks for functional groups present in TRC* and TLC* resins indicated in the spectra correspond to CH 2 stretching at 2925 cm À1 , C O stretching at 1715 and 1036 cm À1 , OH deformation from carboxylic acid at 1450 cm À1 and C O C stretch vibration from ether groups at 1236 cm À1 . 35,43,44 C H out of plane bending in vinyl ester monomer is shown by the peak at 943 cm À1 , 45 whereas aromatic C H bond bending of the vinyl group is given by the peak at 828 cm À1 . 35 A symmetrical C O C stretch is assigned to the peak centered at 1180 cm À1 in TLC* resin.…”

“…36 The peak at 1509 cm À1 corresponds to saturated C C carbon stretch in the aromatic ring present in polyvinyl ester and is therefore used as the nonreactive reference peak for conversion calculation in TRC* and TLC* resins. 43,47 The monomer conversions for TRC* and TLC* resins were calculated and be 63% and 67%, respectively. As expected, photopolymerization of a mixture of aromatic and aliphatic diacrylates in TLC* resin gives rise to an intramolecular cyclization that causes microgelation, trapping unreactive acrylate groups in the monomer.…”