Effect of coupling agents on reinforcing potential of recycled carbon fibre for polypropylene composite

K. H. Wong, D. Syed Mohammed, S. J. Pickering, R. Brooks

Research output: Journal PublicationArticlepeer-review

159 Citations (Scopus)


Polypropylene (PP) composites reinforced with recycled carbon fibre have been prepared through extrusion compounding and injection moulding. The reinforcing potential of the recycled fibre was increased by improving the interfacial adhesion between the fibre and PP matrix and this was done by the addition of maleic anhydride grafted polypropylene (MAPP) coupling agents. Three MAPP couplers with different molecular weights and maleic anhydride contents were considered. The effects on the mechanical properties of the composite were studied, and scanning electron microscopy (SEM) was used to study the fracture morphology of the tensile specimens. It was observed that with the addition of MAPP the interfacial adhesion was improved as fewer fibres were pulled-out and less debonding was seen. A microbond test was performed and a significant improvement in interfacial shear strength was measured. This resulted in composites with higher tensile and flexural strengths. The maximum strength was achieved from MAPP with the highest molecular weight. Increased modulus was also achieved with certain grades of MAPP. It was also found that the composite impact strength was improved significantly by MAPP, due to a higher compatibility between the fibre and matrix, which reduced crack initiation and propagation.

Original languageEnglish
Pages (from-to)835-844
Number of pages10
JournalComposites Science and Technology
Issue number7
Publication statusPublished - 13 Apr 2012
Externally publishedYes


  • A. Carbon fibres
  • A. Coupling agents
  • A. Recycling
  • B. Mechanical properties
  • E. Injection moulding

ASJC Scopus subject areas

  • Ceramics and Composites
  • General Engineering


Dive into the research topics of 'Effect of coupling agents on reinforcing potential of recycled carbon fibre for polypropylene composite'. Together they form a unique fingerprint.

Cite this