An Analysis of the Properties of Recycled PET Fiber-Gypsum Composites

Abstract

The production of composites materials has gained importance due to the increasing and more complex needs of today. Materials used for composites, where the aim is to produce products that have better properties compared to the components forming the main body, can be composed of products obtained from raw materials or recycled products. By adding PET fibers, which are among recycled products, into the composites, the use of limited raw material resources and the harm to the environment during the processes during the lifecycle of the product is minimized. Additionally, gypsum, which is used as matrix in the composite, is easily obtainable, has adequate raw material resources, is easily given form, produces a clean-flat surface, has sufficient tensile and compressive strength and is a good humidity equalizer and sound regulator. However, gypsum has a low impact strength and toughness value. As it is necessary to increase its impact resistance, some research is carried out to this end. In this study, composite material is produced by adding polyethylene terephthalate fibers that are recycled products manufactured from recycled PET bottles and which have not been tried before and PVA based adherence-enhancing additive into the gypsum matrix to improve the properties of gypsum. Test results show that with the addition of fiber the flexural strength of gypsum has somewhat decreased but the addition of the adherence-enhancing additive has considerably increased the compressive and flexural strength. As expected from fiber reinforced composites, the impact and toughness values of the material has considerably increased. The positive effect of the adherence additive between the gypsum matrix and the fiber is clearly visible in the micro analysis carried out.

Study of the Mechanical and Physical Behavior of Gypsum Boards with Plastic Cable Waste Aggregates and Their Application to Construction Panels

“…However, in all the impacts on the samples with PR, the steel ball rebounded, which corroborated the increase in elasticity achieved in the composites under study (verified and analyzed with Young’s modulus in the previous section), showing the composite E 0.8 50PR the highest shock-impact resistance (0.73 mm mark depth). These results are also similar to those obtained by other researchers [ 36 , 37 , 40 , 41 ], in which the improvement of the shock-impact resistance capacity was observed in mixtures of plaster with polymeric residues.…”

“…From the load-displacement graphs of each of the mixtures, the higher flexural strength and stiffness of the reference, as well as the reduction of the flexural strength of the composites with PR and their higher deformation capacity (elasticity), can be deduced (Figure 9). Similar results have also been observed in the studies of other researchers [14,40,41,43] where, by introducing polymeric residues, the deforming capacity of the mixtures was increased.…”

“…In other words, the incorporation of PR produced a lower porosity, which resulted in a higher value for the apparent density of the composites with PR, compared to the reference one; the higher the PR content, the higher the density, as the pore volume decreased. Similar results have also been observed in the studies of other researchers [14,40,41,43] where, by introducing polymeric residues, the deforming capacity of the mixtures was increased.…”

Effect of Addition of Polypropylene Fibers on The Properties of Gypsum Blocks

“…On the other hand, when polyethylene fibers were added they showed a detrimental effect on strength. However, when an adhesive agent was added, the strength values increased over the control fibers free sample [8].…”

Microstructure and compressive strength of gypsum-bonded composites with papers, paperboards and Tetra Pak recycled materials

“…Scanning electron microscopy has been used to study fiber-based composites. Some of these studies have been conducted to investigate the behavior of fibers, the fiber fracture mechanisms and the microstructure of the cement [4,19,20] or gypsum [21][22][23][24] used as matrices. These studies characterized the microstructural properties of the fiber-matrix interactions.…”