Towards "green" viscoelastically prestressed composites: Cellulose fibre reinforcement. (1st December 2018)

• Record Type: Journal Article
• Authors: Qin, Yang; Fancey, Kevin S.
• Is Part Of: Composites. Number 154(2018)
• Page Start: 439
• Page End: 448
• Publication Date: 2018-12-01
• Subjects: Polymer-matrix composites (PMCs) -- Residual/internal stress -- Mechanical testing -- Viscoelasticity; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2018.08.096
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: With growing concerns over environmental issues, fibre reinforced composites based on renewable, biodegradable low-cost cellulosic/cellulose fibres increasingly attract interest. This paper reports on the first study to produce viscoelastically prestressed polymeric matrix composites (VPPMCs) using regenerated cellulose/viscose continuous fibres. The aim was to demonstrate that this prestressing technique could improve the mechanical properties of a cellulose fibre reinforced composite without the need to increase section mass or thickness. By investigating the viscoelastic properties of cellulose yarn, a suitable load was applied to subject the fibres to tensile creep. The load was then released and the loose yarns were moulded into a polyester resin matrix. Following matrix solidification, the viscoelastically recovering fibres imparted compressive stresses to the matrix. The mechanical properties of these cellulose fibre VPPMCs were investigated by tensile, three-point flexural and Charpy impact tests. Under the creep conditions investigated, the VPPMC samples demonstrated up to 20% increase in tensile strength and modulus and a comparable improvement in flexural properties, compared with control (unstressed) counterparts. Nevertheless, the prestress effect reduced impact toughness by ∼30%, by impeding matrix crack formation and promoting fibre fracture. Based on findings from this paper, all-green VPPMCs may be achieved in the future by considering potentially suitable green resins.