Mechanical properties of recycled glass fibre reinforced nanoclay/unsaturated polyester composites

Abstract

The purpose of this study is to study the effects of montmorillonite (MMT) nanofiller on the mechanical properties of glass fibre recyclates (rGF) reinforced unsaturated polyester (UP) composites. Alumina-silicates nanoclay such as MMT can improves the mechanical performance of polymeric composites. This study uses the mechanical recycling process to grind the GFRP waste into recyclates. MMT nanoclay was dispersed into UP using ultrasonicator. Different weight percentage of rGF at 25 wt.%, 30 wt.% and 40 wt.% were mixed in UP-MMT resin and formed into composites plate using compression moulding. Preliminary study shows that, the tensile strength of 25 wt.% raw rGF-UP composites was approximately 50% lower than of UP. Therefore, raw rGF was sieved into coarse and fine grade to improve the tensile properties of the composites. Compared to raw rGF, sieved rGF has better tensile strength due to better fibre distribution of rGF and uniformed fibre length. Coarse rGF composites which contain relatively larger aspect ratio (longer fibre length) have better tensile properties than fine rGF. The inclusion of MMT nanofiller in polyester resin enables the tensile strength of the composites to increase. For example, the tensile strength of 40 wt.% fine rGF-3 wt.% MMT hybrid composites is higher by 14% than the non-hybrid 40 wt.% fine rGF. Scanning electron microscopy shows good fibre/resin adhesion for MMT below 3 wt.%. While at 5 wt.% MMT, the UP resin becomes degraded and developed poor adhesion of resin to the recyclate fibres.

Fire resistance and mechanical properties of powder-epoxy composites reinforced with recycled glass fiber laminate

“…Hardness, impact strength, Young modulus, ultimate tensile strength, ultimate flexural strength and elastic modulus have been improved by 42.5, 11, 41.5, 37, 10.9 and 53%, respectively, compared to unmodified resin. Moreover, although the C fraction contained fibers of higher length, these composites were characterized by lower strength and stiffness than the composites with D fraction, which is opposite to literature data [26,27]. It may be due to the presence of agglomerates formed during the mixing of powder materials.…”

“…It may be caused by nonuniform mixing of powderepoxy resin with additives. In turn, the composites containing fraction C were characterized by a lower tensile stress and Young's modulus, in comparison with EPD composites, which is not in accordance with the literature data, because the coarse fraction contains longer fibers, which should promote greater strength [26,27]. Among these materials, the best results (Young's modulus 2.91 GPa instead 2.09 GPa, tensile strength 41.5 MPa instead 37.6 MPa) were obtained for the EPC10.…”

“…Based on SEM analysis of large fiber/matrix debonding cracks at the fracture surfaces of the composites, they found that the low failure strength and strain of the composites is due to insufficient bonding between the recycled fiber and the new polyester matrix. Hanan et al [26] have also showed that the addition of fine and coarse fraction to unsaturated polyester resin (UPR) improves the modulus of composites. The composites with coarse fraction which contain relatively larger aspect ratio (longer fiber length) have better stiffness than these with fine rGF (recycled glass fiber).…”

Degradable and Recyclable Unsaturated Polyester Resin Based on the Selective Cleavage of a Hindered C–O Bond

“…Unsaturated polyester resins (UPRs) are widely used in various applications for their inexpensive monomers, simple synthesis and processing, as well as their excellent thermal and mechanical properties. , However, the highly crosslinked network structure leads to the insolubility and nonmelting of UPR, making the resin very difficult to deal with. , With the extensive use of UPRs and UPR-based composites, massive waste materials put great pressure on the environment. − Traditional dealing methods such as mechanical crushing and incineration are often inefficient in resource and material recovery and usually lead to inevitably secondary pollution. − With the increase of environmental and economic awareness, developing degradable UPRs and their green recycling technologies has become a very important and necessary topic.…”

Catalytic degradation of a thermosetting unsaturated polyester via a green coupled acid catalytic system

“…11 The mechanical method is far from practical application owing to the poor quality of the recycled composite material prepared from the waste material. 12,13 Pyrolysis involves the non-selective cleavage of chemical bonds during the degradation process, which is energy-consuming and inevitably produces a complex mixture of gaseous, liquid, and solid chemicals. 14 In contrast, the chemical method offers a prospect of closed-loop recycling of WTUPR by transforming the waste into useful chemicals, such as small molecules, oligomers, or other chemicals.…”