Pub Date : 2020-09-30DOI: 10.1177/0021955X20959302
J. Guillén-Mallette, P. Gonzalez-Chi, RH Cruz-Estrada, RN Miranda-Flores y, Ma Rivero-Ayala
Recycling printed polypropylene (PP) labels and printed polyolefins (PO) caps as a chemical foaming agent to produce foam products is studied. An experimental Taguchi L16 design with seven experimental variables involved is used: talc content and screw angular velocity, at four experimental levels; extrusion temperature profile and extruded formulations, at three levels; and, type of label washing process, the use of metal mesh and the type of label drying process, at two levels. As control variables, the morphology of the cells and the density of the foamed products are utilized. The labels/caps mixture was composed of 21% printed PP labels and 79% printed polyolefin caps. Part of the pigments from the ink labels and some polar groups of low-molecular-weight materials present in the molten polymer were partially decomposed at the PP processing temperatures, which contributes to the cell formation and growth of the extruded foams. The labels/caps mixture generated large ellipsoidal and elongated cells (740 µm) oriented in the extrusion direction because of the presence of high density polyethylene (HDPE) and EVA in the recycled PP caps and labels. The experimental factors that influenced the foam density were the screw angular velocity and temperature, and the cell morphology depended on the matrix crystallinity and melt strength.
{"title":"Recycling printed polypropylene labels and polyolefins caps as chemical foaming agent to produce foam products","authors":"J. Guillén-Mallette, P. Gonzalez-Chi, RH Cruz-Estrada, RN Miranda-Flores y, Ma Rivero-Ayala","doi":"10.1177/0021955X20959302","DOIUrl":"https://doi.org/10.1177/0021955X20959302","url":null,"abstract":"Recycling printed polypropylene (PP) labels and printed polyolefins (PO) caps as a chemical foaming agent to produce foam products is studied. An experimental Taguchi L16 design with seven experimental variables involved is used: talc content and screw angular velocity, at four experimental levels; extrusion temperature profile and extruded formulations, at three levels; and, type of label washing process, the use of metal mesh and the type of label drying process, at two levels. As control variables, the morphology of the cells and the density of the foamed products are utilized. The labels/caps mixture was composed of 21% printed PP labels and 79% printed polyolefin caps. Part of the pigments from the ink labels and some polar groups of low-molecular-weight materials present in the molten polymer were partially decomposed at the PP processing temperatures, which contributes to the cell formation and growth of the extruded foams. The labels/caps mixture generated large ellipsoidal and elongated cells (740 µm) oriented in the extrusion direction because of the presence of high density polyethylene (HDPE) and EVA in the recycled PP caps and labels. The experimental factors that influenced the foam density were the screw angular velocity and temperature, and the cell morphology depended on the matrix crystallinity and melt strength.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"11 1","pages":"733 - 756"},"PeriodicalIF":2.5,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74815928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-20DOI: 10.1177/0021955X20956925
Jianwei Li, Ni Yu, Yuanqing Ding, T. Xu, Guangcheng Zhang, Zhanxin Jing, Xuetao Shi
Polyimide (PI) foams have been developed for decades and widely used as thermal insulation materials. However, the limited mechanical and thermal properties continually being a serious problem that restrict their further applications. In this study, a series of rigid PI foams with excellent mechanical and thermal performance were fabricated by the reaction of benzophenone-3,3',4,4'-tetracarboxylic dianhydride (BTDA) with two diamines of 2–(4-aminophenyl)-5-aminobenzimidazole (BIA) and 4,4'-diaminodiphenyl ether (ODA) with various molar ratios, and the cis-5-norbornene-endo-2,3-dicarbox-ylic acid (NA) was introduced as end-capping and foaming agent. The results demonstrate that the foaming degree decreases with increasing the BIA molar ratio in the polymer chains owing to the elevated melt viscosity of precursor. Furthermore, the prepared rigid PI foams exhibit excellent thermal and mechanical properties. When the BIA contend up to 40 mol%, the glass transition temperature (Tg) and the temperature at 10% of weight loss (Td 10 % ) of PI foam increased ∼80°C and ∼35°C in comparison with the pristine PI-0, respectively. In addition, the compressive strength and modulus at 10% strain of PI-4 reached to 5.48 MPa and 23.8 MPa, respectively. For the above-mentioned advantages, the prepared rigid PI foams are promising candidates as thermal insulation and structure support composite materials in the aerospace and aviation industries.
{"title":"Fabrication of rigid polyimide foams with overall enhancement of thermal and mechanical properties","authors":"Jianwei Li, Ni Yu, Yuanqing Ding, T. Xu, Guangcheng Zhang, Zhanxin Jing, Xuetao Shi","doi":"10.1177/0021955X20956925","DOIUrl":"https://doi.org/10.1177/0021955X20956925","url":null,"abstract":"Polyimide (PI) foams have been developed for decades and widely used as thermal insulation materials. However, the limited mechanical and thermal properties continually being a serious problem that restrict their further applications. In this study, a series of rigid PI foams with excellent mechanical and thermal performance were fabricated by the reaction of benzophenone-3,3',4,4'-tetracarboxylic dianhydride (BTDA) with two diamines of 2–(4-aminophenyl)-5-aminobenzimidazole (BIA) and 4,4'-diaminodiphenyl ether (ODA) with various molar ratios, and the cis-5-norbornene-endo-2,3-dicarbox-ylic acid (NA) was introduced as end-capping and foaming agent. The results demonstrate that the foaming degree decreases with increasing the BIA molar ratio in the polymer chains owing to the elevated melt viscosity of precursor. Furthermore, the prepared rigid PI foams exhibit excellent thermal and mechanical properties. When the BIA contend up to 40 mol%, the glass transition temperature (Tg) and the temperature at 10% of weight loss (Td 10 % ) of PI foam increased ∼80°C and ∼35°C in comparison with the pristine PI-0, respectively. In addition, the compressive strength and modulus at 10% strain of PI-4 reached to 5.48 MPa and 23.8 MPa, respectively. For the above-mentioned advantages, the prepared rigid PI foams are promising candidates as thermal insulation and structure support composite materials in the aerospace and aviation industries.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"1 1","pages":"717 - 731"},"PeriodicalIF":2.5,"publicationDate":"2020-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73124491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-14DOI: 10.1177/0021955X20959301
T. Azdast, R. Hasanzadeh
Nowadays, polymeric foams have attracted particular attention in scientific and industrial societies due to their unique properties, such as high strength to weight ratio, excellent thermal and sound insulation, and low cost. Researchers have shown that the extraordinary properties of polymeric foams such as superior thermal insulation, can be achieved by increasing the cell density/decreasing the cell size. In this regard, firstly, the most important foaming processes, i.e. batch, extrusion, and injection molding are studied in the present research. Then, cell nucleation stage as the most crucial phenomenon for achieving high cell density/small cell size is investigated in detail. In the next step, the most important researches in the field of polymeric foams are introduced in which the largest cell densities/smallest cell sizes have been achieved. The investigations show that the most remarkable results (highest cell densities/smallest cell sizes) belong to the batch process. Also, the use of nucleating agents, increasing the solubility of blowing agent into the polymer, and the use of nanoparticles are the most efficient solutions to achieve microcellular and nanocellular structures.
{"title":"Increasing cell density/decreasing cell size to produce microcellular and nanocellular thermoplastic foams: A review","authors":"T. Azdast, R. Hasanzadeh","doi":"10.1177/0021955X20959301","DOIUrl":"https://doi.org/10.1177/0021955X20959301","url":null,"abstract":"Nowadays, polymeric foams have attracted particular attention in scientific and industrial societies due to their unique properties, such as high strength to weight ratio, excellent thermal and sound insulation, and low cost. Researchers have shown that the extraordinary properties of polymeric foams such as superior thermal insulation, can be achieved by increasing the cell density/decreasing the cell size. In this regard, firstly, the most important foaming processes, i.e. batch, extrusion, and injection molding are studied in the present research. Then, cell nucleation stage as the most crucial phenomenon for achieving high cell density/small cell size is investigated in detail. In the next step, the most important researches in the field of polymeric foams are introduced in which the largest cell densities/smallest cell sizes have been achieved. The investigations show that the most remarkable results (highest cell densities/smallest cell sizes) belong to the batch process. Also, the use of nucleating agents, increasing the solubility of blowing agent into the polymer, and the use of nanoparticles are the most efficient solutions to achieve microcellular and nanocellular structures.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"21 1","pages":"769 - 797"},"PeriodicalIF":2.5,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88978758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-03DOI: 10.1177/0021955X20952751
Junjie Pan, Feng Chen, E. Cabrera, Zhiyu Min, Shilun Ruan, Min Wu, Dan Zhang, J. Castro, L. J. Lee
This work presents a facile method to produce low-density PET foams using pristine semi-crystalline resin by moisture-induced controlled-hydrolysis in a tight processing window (moisture content ∼ 0.12 wt.%). We investigated the effect of moisture and moisture containing activated carbon (AC) on the foam expansion ratio, cell morphology, and PET resin degradation and crystallization properties. Controlled-hydrolysis increased the melt-flow rate of PET resin (intrinsic viscosity: 0.52 to 0.54 dL/g) without losing crystallinity, and thus the PET foams possess better tensile properties (∼2 MPa stress and ∼100% strain) and higher thermal stability (>200°C) than chemically modified PET foams. The foam density could be made as low as ∼ 0.15 g/cm3 using a lab scale twin-screw extruder. A strand array die was also designed to produce plate-shaped foam samples. AC allowed easier control of the moisture content and delayed resin degradation in extrusion. Both AC and micrographite (mGr) could stabilize the PET foam morphology in extrusion and serve as good infrared attenuation agents (IAAs) in a simulated housing thermal insulation experiment.
{"title":"Carbon particulate and controlled-hydrolysis assisted extrusion foaming of semi-crystalline polyethylene terephthalate for the enhanced thermal insulation property","authors":"Junjie Pan, Feng Chen, E. Cabrera, Zhiyu Min, Shilun Ruan, Min Wu, Dan Zhang, J. Castro, L. J. Lee","doi":"10.1177/0021955X20952751","DOIUrl":"https://doi.org/10.1177/0021955X20952751","url":null,"abstract":"This work presents a facile method to produce low-density PET foams using pristine semi-crystalline resin by moisture-induced controlled-hydrolysis in a tight processing window (moisture content ∼ 0.12 wt.%). We investigated the effect of moisture and moisture containing activated carbon (AC) on the foam expansion ratio, cell morphology, and PET resin degradation and crystallization properties. Controlled-hydrolysis increased the melt-flow rate of PET resin (intrinsic viscosity: 0.52 to 0.54 dL/g) without losing crystallinity, and thus the PET foams possess better tensile properties (∼2 MPa stress and ∼100% strain) and higher thermal stability (>200°C) than chemically modified PET foams. The foam density could be made as low as ∼ 0.15 g/cm3 using a lab scale twin-screw extruder. A strand array die was also designed to produce plate-shaped foam samples. AC allowed easier control of the moisture content and delayed resin degradation in extrusion. Both AC and micrographite (mGr) could stabilize the PET foam morphology in extrusion and serve as good infrared attenuation agents (IAAs) in a simulated housing thermal insulation experiment.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"71 1","pages":"695 - 716"},"PeriodicalIF":2.5,"publicationDate":"2020-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89835140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1177/0021955X20950242
Jinwei Chen, Ling Yang, Qunshan Mai, Mei Li, Lixuan Wu, Ping Kong
Using supercritical carbon dioxide (sc-CO2) as a physical foaming agent, the effect of sc-CO2 on the formation of crystalline domains and subsequently on the foaming behaviors of the two grades of PLA with different D-isomer content were investigated in a wide foaming temperature range. The PLA’s final crystallinity is significantly increased with decreasing annealing temperature and by reducing the D-isomer content. Cellular structure results show that not only the crystallinity but also the crystalline morphology play an important role in cellular structure. A novel spherulite morphology including ringless and ring-banded morphology in the same spherulite was formed at lower foaming temperature, as a result, some entities were nonuniformly distributed in the PLA foams. Uniform and closed cellular structure were obtained when only the ring-banded spherulites were formed. An opened and interconnected cellular structure is tended to be formed because of the synergistic effect of high temperature and plasticization of CO2. Based on the crystallinity and morphology, a suitable foaming window as a function of temperature is proposed. It is found that PLA with 4.1% D-isomer content had much broader suitable foaming window range to produce homogeneous cellular structure.
{"title":"Foaming behavior of poly(lactic acid) with different D-isomer content based on supercritical CO2-induced crystallization","authors":"Jinwei Chen, Ling Yang, Qunshan Mai, Mei Li, Lixuan Wu, Ping Kong","doi":"10.1177/0021955X20950242","DOIUrl":"https://doi.org/10.1177/0021955X20950242","url":null,"abstract":"Using supercritical carbon dioxide (sc-CO2) as a physical foaming agent, the effect of sc-CO2 on the formation of crystalline domains and subsequently on the foaming behaviors of the two grades of PLA with different D-isomer content were investigated in a wide foaming temperature range. The PLA’s final crystallinity is significantly increased with decreasing annealing temperature and by reducing the D-isomer content. Cellular structure results show that not only the crystallinity but also the crystalline morphology play an important role in cellular structure. A novel spherulite morphology including ringless and ring-banded morphology in the same spherulite was formed at lower foaming temperature, as a result, some entities were nonuniformly distributed in the PLA foams. Uniform and closed cellular structure were obtained when only the ring-banded spherulites were formed. An opened and interconnected cellular structure is tended to be formed because of the synergistic effect of high temperature and plasticization of CO2. Based on the crystallinity and morphology, a suitable foaming window as a function of temperature is proposed. It is found that PLA with 4.1% D-isomer content had much broader suitable foaming window range to produce homogeneous cellular structure.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"5 1","pages":"675 - 694"},"PeriodicalIF":2.5,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75799705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-20DOI: 10.1177/0021955X20948560
L. Songtipya, Ponusa Songtipya, T. Prodpran, E. Kalkornsurapranee, J. Johns
The water-soluble loose-fill foam obtained from tamarind seed polysaccharide (TSP) was successfully prepared by a combination of mechanical frothing and freeze-drying process. The effects of TSP concentration, plasticizer content, and surfactant content on the cellular morphology, physical properties, mechanical properties, and moisture absorption were investigated. The cellular structure of TSP foam exhibited an open cell structure with a non-uniform size of the cell window, and the density varied in a range of ∼0.006–0.106 g/cm3. Foam preparation with high TSP concentration, low plasticizer as well as glycerol content enhanced the mechanical properties of the obtained foam, including tensile strength, compressive strength, and hardness. The high compressive strength of TSP foams up to ∼1.03 MPa can be produced which demonstrates that TSP foam is capable to use as a loose-fill product.
{"title":"Fabrication of water-soluble loose-fill foam from tamarind (Tamarindus indica L.) seed polysaccharide by mechanical frothing and freeze-drying process","authors":"L. Songtipya, Ponusa Songtipya, T. Prodpran, E. Kalkornsurapranee, J. Johns","doi":"10.1177/0021955X20948560","DOIUrl":"https://doi.org/10.1177/0021955X20948560","url":null,"abstract":"The water-soluble loose-fill foam obtained from tamarind seed polysaccharide (TSP) was successfully prepared by a combination of mechanical frothing and freeze-drying process. The effects of TSP concentration, plasticizer content, and surfactant content on the cellular morphology, physical properties, mechanical properties, and moisture absorption were investigated. The cellular structure of TSP foam exhibited an open cell structure with a non-uniform size of the cell window, and the density varied in a range of ∼0.006–0.106 g/cm3. Foam preparation with high TSP concentration, low plasticizer as well as glycerol content enhanced the mechanical properties of the obtained foam, including tensile strength, compressive strength, and hardness. The high compressive strength of TSP foams up to ∼1.03 MPa can be produced which demonstrates that TSP foam is capable to use as a loose-fill product.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"24 1","pages":"643 - 658"},"PeriodicalIF":2.5,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84343634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-16DOI: 10.1177/0021955X20950224
Shuai Li, X. Sun, Rui Wang, Yan Hu, Xiaofei Ma, Jiachang Wang
By using a standard stretch spline as the research object, the influence of gas counter pressure (GCP) technology on melt foaming behavior in chemical foaming injection molding (CFIM) process was investigated. Related experimental line for GCP assisted CFIM foam was designed, and the effect of GCP technology on melt flow front, spline surface quality and internal cell was studied. According to the results obtained from the experiment, two critical GCP pressures and one critical GCP holding time were innovation proposed. Two critical GCP pressures are the critical GCP pressure of melt flow front cell not cracking and the critical GCP pressure of melt not foaming, respectively. The critical GCP holding time is the secondary foaming behavior time. Based on the proposed critical GCP pressures and critical GCP holding time, the influence mechanism of GCP technology on melt foaming action during CFIM process was revealed.
{"title":"Experimental investigation on the forming and evolution process of cell structure in gas counter pressure assisted chemical foaming injection molded parts","authors":"Shuai Li, X. Sun, Rui Wang, Yan Hu, Xiaofei Ma, Jiachang Wang","doi":"10.1177/0021955X20950224","DOIUrl":"https://doi.org/10.1177/0021955X20950224","url":null,"abstract":"By using a standard stretch spline as the research object, the influence of gas counter pressure (GCP) technology on melt foaming behavior in chemical foaming injection molding (CFIM) process was investigated. Related experimental line for GCP assisted CFIM foam was designed, and the effect of GCP technology on melt flow front, spline surface quality and internal cell was studied. According to the results obtained from the experiment, two critical GCP pressures and one critical GCP holding time were innovation proposed. Two critical GCP pressures are the critical GCP pressure of melt flow front cell not cracking and the critical GCP pressure of melt not foaming, respectively. The critical GCP holding time is the secondary foaming behavior time. Based on the proposed critical GCP pressures and critical GCP holding time, the influence mechanism of GCP technology on melt foaming action during CFIM process was revealed.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"604 1","pages":"659 - 674"},"PeriodicalIF":2.5,"publicationDate":"2020-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80656661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-05DOI: 10.1177/0021955X20944971
Habib Haji Avdi, M. Nasiri, Mohammad Javad Tehrani, Maryam Alizadeh Aghdam, F. Abbasi
In this research, in-situ suspension polymerization of styrene in the presence of graphene, without any blowing agent, was investigated. Steam used in the expansion process of graphene-filled expandable polystyrene (GEPS). The dispersed graphene nano-sheets in the polystyrene matrix may absorb water in high temperatures, which evaporates by lowering the pressure and expansion precedes. The effects of graphene type and loading and steam temperature on the expansion ratio evaluated. Scanning electron microscopy (SEM) used to reveal the cross-section morphologies before and after expansion. The effect of graphene on the polymerization kinetics evaluated by differential scanning calorimetry (DSC). The results showed that by increasing the graphene loading, the rate of polymerization decreased, and the expansion ratio increased. The highest expansion ratio of about 4.8 was for particles containing 0.4% of graphene. Therefore, it was shown that by using graphene as a dispersed phase, polystyrene particles expanded without any organic blowing agents. Here, the idea of expandable polymers without any embedded blowing agent is introduced, which eliminates the release of volatile organic compounds and makes the process environmentally friendly.
{"title":"Expandable polystyrene without any embedded blowing agent","authors":"Habib Haji Avdi, M. Nasiri, Mohammad Javad Tehrani, Maryam Alizadeh Aghdam, F. Abbasi","doi":"10.1177/0021955X20944971","DOIUrl":"https://doi.org/10.1177/0021955X20944971","url":null,"abstract":"In this research, in-situ suspension polymerization of styrene in the presence of graphene, without any blowing agent, was investigated. Steam used in the expansion process of graphene-filled expandable polystyrene (GEPS). The dispersed graphene nano-sheets in the polystyrene matrix may absorb water in high temperatures, which evaporates by lowering the pressure and expansion precedes. The effects of graphene type and loading and steam temperature on the expansion ratio evaluated. Scanning electron microscopy (SEM) used to reveal the cross-section morphologies before and after expansion. The effect of graphene on the polymerization kinetics evaluated by differential scanning calorimetry (DSC). The results showed that by increasing the graphene loading, the rate of polymerization decreased, and the expansion ratio increased. The highest expansion ratio of about 4.8 was for particles containing 0.4% of graphene. Therefore, it was shown that by using graphene as a dispersed phase, polystyrene particles expanded without any organic blowing agents. Here, the idea of expandable polymers without any embedded blowing agent is introduced, which eliminates the release of volatile organic compounds and makes the process environmentally friendly.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"8 1","pages":"535 - 544"},"PeriodicalIF":2.5,"publicationDate":"2020-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83358759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-05DOI: 10.1177/0021955X20948562
Mylene S. Cadete, T. Gomes, P. Carvalho, V. Neto
With the increase use of plastics, there is currently a concern with the waste of materials, resulting in a series of challenges and opportunities for the waste management sector. In the present work, poly(ethylene terephthalate) (PET) foam was produced from recycled PET (RPET) from used water bottles. The recycled material was manually prepared and foamed in batches with the assistance of nitrogen gas as the physical blowing agent. RPET was characterized using Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The influence of the pressure on the foam formation was studied and the results obtained showed that this variable influences the final product characteristics. To evaluate the behavior of the foams, their morphology, response to deformation when subject to compression and their thermal conductivities were studied. The morphology analysis showed that operating at higher-pressure results in bigger pore size but also in an increased pore size heterogeneous distribution, and foams that exhibit a higher thermal conductivity.
{"title":"Polymeric foams from recycled thermoplastic poly(ethylene terephthalate)","authors":"Mylene S. Cadete, T. Gomes, P. Carvalho, V. Neto","doi":"10.1177/0021955X20948562","DOIUrl":"https://doi.org/10.1177/0021955X20948562","url":null,"abstract":"With the increase use of plastics, there is currently a concern with the waste of materials, resulting in a series of challenges and opportunities for the waste management sector. In the present work, poly(ethylene terephthalate) (PET) foam was produced from recycled PET (RPET) from used water bottles. The recycled material was manually prepared and foamed in batches with the assistance of nitrogen gas as the physical blowing agent. RPET was characterized using Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The influence of the pressure on the foam formation was studied and the results obtained showed that this variable influences the final product characteristics. To evaluate the behavior of the foams, their morphology, response to deformation when subject to compression and their thermal conductivities were studied. The morphology analysis showed that operating at higher-pressure results in bigger pore size but also in an increased pore size heterogeneous distribution, and foams that exhibit a higher thermal conductivity.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"11 6 1","pages":"609 - 622"},"PeriodicalIF":2.5,"publicationDate":"2020-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85723164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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