Pub Date : 2023-11-29DOI: 10.1177/14777606231207000
Maryam Parsamanesh, F. Abbassi‐Sourki, M. Karrabi, S. Soltani
Thermomechanical devulcanization of butyl rubber (BR1), bromobutyl rubber (BR2) vulcanizates, both prepared in laboratory, and a waste commercial butyl rubber (BR3) using a twin-screw extruder is reported. The commercial butyl rubber vulcanizate (BR3) was used as a tire curing bladder and the waste rubber received from a tire manufacturing company. The devulcanization process was carried out at various barrel temperatures and screw speeds (40, 80 and 120 r/min). The lowest sol fraction was obtained for devulcanized waste commercial butyl rubber (D-BR3). According to Horikx theory, devulcanized butyl rubber (D-BR1) presented mainly crosslink breakup while devulcanized bromobutyl rubber (D-BR2) and devulcanized waste commercial butyl rubber (D-BR3) showed a mixture of main chain and crosslink scission. As cure rheographs at 190°C indicated, the addition of devulcanized rubbers to the corresponding virgin ones influenced both scorch and optimal cure times. The tensile properties of devulcanized/virgin rubber blends changed depending on the blend type and virgin rubber. The stress relaxation experiment revealed that the addition of devulcanized rubber to virgin one mostly influenced short relaxation times and also decreased G0. BR1/D-BR3 blends exhibited higher elastic component than BR1/D-BR1 and BR2/D-BR2 samples. The Han plots revealed higher compatibility for BR2/D-BR2 blends.
{"title":"Thermomechanical devulcanization of butyl rubber using twin-screw extruder: Process parameters, viscoelastic and compatibility properties","authors":"Maryam Parsamanesh, F. Abbassi‐Sourki, M. Karrabi, S. Soltani","doi":"10.1177/14777606231207000","DOIUrl":"https://doi.org/10.1177/14777606231207000","url":null,"abstract":"Thermomechanical devulcanization of butyl rubber (BR1), bromobutyl rubber (BR2) vulcanizates, both prepared in laboratory, and a waste commercial butyl rubber (BR3) using a twin-screw extruder is reported. The commercial butyl rubber vulcanizate (BR3) was used as a tire curing bladder and the waste rubber received from a tire manufacturing company. The devulcanization process was carried out at various barrel temperatures and screw speeds (40, 80 and 120 r/min). The lowest sol fraction was obtained for devulcanized waste commercial butyl rubber (D-BR3). According to Horikx theory, devulcanized butyl rubber (D-BR1) presented mainly crosslink breakup while devulcanized bromobutyl rubber (D-BR2) and devulcanized waste commercial butyl rubber (D-BR3) showed a mixture of main chain and crosslink scission. As cure rheographs at 190°C indicated, the addition of devulcanized rubbers to the corresponding virgin ones influenced both scorch and optimal cure times. The tensile properties of devulcanized/virgin rubber blends changed depending on the blend type and virgin rubber. The stress relaxation experiment revealed that the addition of devulcanized rubber to virgin one mostly influenced short relaxation times and also decreased G0. BR1/D-BR3 blends exhibited higher elastic component than BR1/D-BR1 and BR2/D-BR2 samples. The Han plots revealed higher compatibility for BR2/D-BR2 blends.","PeriodicalId":508656,"journal":{"name":"Progress in Rubber, Plastics and Recycling Technology","volume":"118 6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139212810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-27DOI: 10.1177/14777606231218350
Kankomba Kankompe, Sizo Ncube, N. Nkomo, Nqobizitha Ndebele, P. Gonde, L. Nkiwane
Millions of used or worn-out tyres are disposed of by many countries annually. These tyres can be put to good use when recycled. Used tyres are among the most problematic and challenging sources of solid waste, especially in landfills. Therefore, the use of waste tyres for composite materials having desired performance properties can be used as a means of disposing of the tyres. Fibrous material-reinforced composites with enhanced physical and mechanical performance and incorporating sisal fibres were produced using waste tyre material, sisal, and polyester resin. The physical and mechanical properties of hybrid composite board panels, including flexural strength, compression strength, tensile strength, and water absorption, were determined according to ASTM Standards. The rubber tyre particles used in the study had a size of 1.00 mm, and the sisal used had an average length of 6mm. A systematic experimental design was formulated and worked accordingly in the fabrication of the composite. The hybrid composite produced has adequate mechanical properties to perform as a substitute for solid wood in several applications such as tabletops, general purpose, load-bearing boards, ceiling boards, furniture, door panels and partitioning boards.
{"title":"Mechanical properties of a hybrid waste tyre, sisal and polyester resin composite fibre board","authors":"Kankomba Kankompe, Sizo Ncube, N. Nkomo, Nqobizitha Ndebele, P. Gonde, L. Nkiwane","doi":"10.1177/14777606231218350","DOIUrl":"https://doi.org/10.1177/14777606231218350","url":null,"abstract":"Millions of used or worn-out tyres are disposed of by many countries annually. These tyres can be put to good use when recycled. Used tyres are among the most problematic and challenging sources of solid waste, especially in landfills. Therefore, the use of waste tyres for composite materials having desired performance properties can be used as a means of disposing of the tyres. Fibrous material-reinforced composites with enhanced physical and mechanical performance and incorporating sisal fibres were produced using waste tyre material, sisal, and polyester resin. The physical and mechanical properties of hybrid composite board panels, including flexural strength, compression strength, tensile strength, and water absorption, were determined according to ASTM Standards. The rubber tyre particles used in the study had a size of 1.00 mm, and the sisal used had an average length of 6mm. A systematic experimental design was formulated and worked accordingly in the fabrication of the composite. The hybrid composite produced has adequate mechanical properties to perform as a substitute for solid wood in several applications such as tabletops, general purpose, load-bearing boards, ceiling boards, furniture, door panels and partitioning boards.","PeriodicalId":508656,"journal":{"name":"Progress in Rubber, Plastics and Recycling Technology","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139229046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-24DOI: 10.1177/14777606231218354
Sudhir Kumar, Inderjeet Singh, Dinesh Kumar, J. Mago, S. S. R. Koloor
This study investigates the impact of heat treatment on the mechanical, morphological, and dimensional properties of polyethylene terephthalate glycol (PETG), a commonly used thermoplastic in 3D printing. Taguchi L25 orthogonal array (OA) was employed to optimize 3D printing parameters, considering factors such as infill percentage (ranging from 20% to 100%), layer height (0.12 mm to 0.28 mm), layer width (0.32 mm to 0.62 mm), and infill pattern. Following ASTM D638 type IV standards, mechanical testing revealed that the optimal printing conditions included a 100% infill percentage, a layer height of 0.16 mm, a layer width of 0.32 mm, and an infill pattern of 5. Specimen 22, produced under these conditions, exhibited a notable stress-bearing capacity of 46.43 ± 1.394 MPa. These results are consistent with previous studies that underscored the significance of high infill percentages and finer layer dimensions in enhancing tensile properties. Subsequently, these optimized specimens were exposed to various heat treatment conditions. It was discovered that heat treatment at 85°C for 15 min yielded the most significant improvements, increasing the stress-bearing capacity to 53.462 ± 1.604 MPa, representing an impressive ∼16% enhancement compared to non-heat-treated specimens. However, this treatment also led to increased brittleness. Morphological analysis using Scanning Electron Microscopy (SEM) further substantiated the findings. Specimens subjected to heat treatment at 85°C exhibited fewer voids and porosities than those printed with lower infill percentages and larger layer dimensions. These observations underscored the importance of adequate infill density and finer printing details for optimizing strength. Regarding dimensional stability, dimensional changes were meticulously measured after heat treatment. Notably, specimens subjected to heat treatment at or near the glass transition temperature (Tg) of PETG experienced the most significant shrinkage. Specimen 6, treated at 85°C, displayed the highest shrinkage, with length and width reductions of 133.30 ± 3.85 mm and 25.90 ± 0.87 mm, respectively.
{"title":"Mechanical, morphological, and dimensional properties of heat-treated fused deposition modeling printed polymeric matrix of polyethylene terephthalate glycol","authors":"Sudhir Kumar, Inderjeet Singh, Dinesh Kumar, J. Mago, S. S. R. Koloor","doi":"10.1177/14777606231218354","DOIUrl":"https://doi.org/10.1177/14777606231218354","url":null,"abstract":"This study investigates the impact of heat treatment on the mechanical, morphological, and dimensional properties of polyethylene terephthalate glycol (PETG), a commonly used thermoplastic in 3D printing. Taguchi L25 orthogonal array (OA) was employed to optimize 3D printing parameters, considering factors such as infill percentage (ranging from 20% to 100%), layer height (0.12 mm to 0.28 mm), layer width (0.32 mm to 0.62 mm), and infill pattern. Following ASTM D638 type IV standards, mechanical testing revealed that the optimal printing conditions included a 100% infill percentage, a layer height of 0.16 mm, a layer width of 0.32 mm, and an infill pattern of 5. Specimen 22, produced under these conditions, exhibited a notable stress-bearing capacity of 46.43 ± 1.394 MPa. These results are consistent with previous studies that underscored the significance of high infill percentages and finer layer dimensions in enhancing tensile properties. Subsequently, these optimized specimens were exposed to various heat treatment conditions. It was discovered that heat treatment at 85°C for 15 min yielded the most significant improvements, increasing the stress-bearing capacity to 53.462 ± 1.604 MPa, representing an impressive ∼16% enhancement compared to non-heat-treated specimens. However, this treatment also led to increased brittleness. Morphological analysis using Scanning Electron Microscopy (SEM) further substantiated the findings. Specimens subjected to heat treatment at 85°C exhibited fewer voids and porosities than those printed with lower infill percentages and larger layer dimensions. These observations underscored the importance of adequate infill density and finer printing details for optimizing strength. Regarding dimensional stability, dimensional changes were meticulously measured after heat treatment. Notably, specimens subjected to heat treatment at or near the glass transition temperature (Tg) of PETG experienced the most significant shrinkage. Specimen 6, treated at 85°C, displayed the highest shrinkage, with length and width reductions of 133.30 ± 3.85 mm and 25.90 ± 0.87 mm, respectively.","PeriodicalId":508656,"journal":{"name":"Progress in Rubber, Plastics and Recycling Technology","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139241996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}