Pub Date : 2020-12-08DOI: 10.1177/0021955X20974291
D. Hu, Chen Zhou, Tao Liu, Yichong Chen, Zhen Liu, Ling Zhao
A simulation of simultaneous bubble nucleation and growth was performed for polyurethane/CO2 physical foaming process. The single-factor and comprehensive effects of viscoelastic properties, Henry’s constant, CO2 diffusion coefficient and surface tension on the cell morphology were numerically analyzed. The results show that the cell density of PU foam (N0) increases and its average cell diameter (Dv) reduces with increased Henry’s constant and slower gas diffusion. Both N0 and Dv reduces with the curing degree (α). In addition, the effects of α and foaming conditions on the cell structure were experimentally investigated. With an increase of α at foamable range, Dv decreases continuously and N0 increases first and then declines. With increasing saturation pressure and depressurization rate or decreasing temperature, N0 increases and Dv reduces. There is an intrinsic correlation between the simulated and experimental variables, and the results of the simulation and experiment are generally consistent.
{"title":"Experimental and numerical study of the polyurethane foaming process using high-pressure CO2","authors":"D. Hu, Chen Zhou, Tao Liu, Yichong Chen, Zhen Liu, Ling Zhao","doi":"10.1177/0021955X20974291","DOIUrl":"https://doi.org/10.1177/0021955X20974291","url":null,"abstract":"A simulation of simultaneous bubble nucleation and growth was performed for polyurethane/CO2 physical foaming process. The single-factor and comprehensive effects of viscoelastic properties, Henry’s constant, CO2 diffusion coefficient and surface tension on the cell morphology were numerically analyzed. The results show that the cell density of PU foam (N0) increases and its average cell diameter (Dv) reduces with increased Henry’s constant and slower gas diffusion. Both N0 and Dv reduces with the curing degree (α). In addition, the effects of α and foaming conditions on the cell structure were experimentally investigated. With an increase of α at foamable range, Dv decreases continuously and N0 increases first and then declines. With increasing saturation pressure and depressurization rate or decreasing temperature, N0 increases and Dv reduces. There is an intrinsic correlation between the simulated and experimental variables, and the results of the simulation and experiment are generally consistent.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"39 1","pages":"927 - 949"},"PeriodicalIF":2.5,"publicationDate":"2020-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88233273","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 : 2020-12-07DOI: 10.1177/0021955X20973599
D. Tammaro, C. Walker, L. Lombardi, U. Trommsdorff
The effect of extrudate swell on extrusion foam of thermoplastic polymers is presented using an experimental approach supported by a modelling of the phenomenon. Its understanding is fundamental in designing the geometry of a die for extrusion foam and to predict foaming. The extrudate swell is the swelling of a viscoelastic material due to a fast elastic recovery after being subjected to stresses. We show that there exists a link between the extrudate swell and foaming, performing experiments with simple and complex extrusion dies to measure the expansion ratio. It was found that the expansion ratio is anisotropic and the anisotropy in the expansion of the foam is due to the extrudate swell that affects strongly the final shape of the product and it cannot be neglected in standard application for extrusion foam. A simple heuristic model was developed to predict the extrudate swell from geometrical parameters and rheological characterization of the fluid. It was found that the foaming mechanism of polyethylene terephthalate, blown with cyclopentane, changes as function of extrudate swell and the lowest density foam is achieved using the die that has the bigger extrudate swell.
{"title":"Effect of extrudate swell on extrusion foam of polyethylene terephthalate","authors":"D. Tammaro, C. Walker, L. Lombardi, U. Trommsdorff","doi":"10.1177/0021955X20973599","DOIUrl":"https://doi.org/10.1177/0021955X20973599","url":null,"abstract":"The effect of extrudate swell on extrusion foam of thermoplastic polymers is presented using an experimental approach supported by a modelling of the phenomenon. Its understanding is fundamental in designing the geometry of a die for extrusion foam and to predict foaming. The extrudate swell is the swelling of a viscoelastic material due to a fast elastic recovery after being subjected to stresses. We show that there exists a link between the extrudate swell and foaming, performing experiments with simple and complex extrusion dies to measure the expansion ratio. It was found that the expansion ratio is anisotropic and the anisotropy in the expansion of the foam is due to the extrudate swell that affects strongly the final shape of the product and it cannot be neglected in standard application for extrusion foam. A simple heuristic model was developed to predict the extrudate swell from geometrical parameters and rheological characterization of the fluid. It was found that the foaming mechanism of polyethylene terephthalate, blown with cyclopentane, changes as function of extrudate swell and the lowest density foam is achieved using the die that has the bigger extrudate swell.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"64 1","pages":"911 - 925"},"PeriodicalIF":2.5,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85042888","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 : 2020-11-25DOI: 10.1177/0021955X20964003
Ziyin Jiang, Yun-fei Zhang, Chang-jing Gong, Zhen Yao, A. Shukla, Kun Cao
Foaming behavior of the fluorinated ethylene propylene copolymer (FEP) and its composites assisted with supercritical carbon dioxide (scCO2) as the blowing agent were investigated. The batch foaming process was applied at temperature ranging from 250°C to 265°C and pressure ranging between 12 MPa and 24 MPa. The optimal foaming temperature and saturation pressure were obtained for both pure FEP and FEP composites with 1 wt% different-sized BaTiO3 as nucleating agent. The cell diameter of pure FEP foam ranging from 80–140 µm was observed while the cell diameter decreased to 20–40 µm after adding BaTiO3 particles. The cell density of foamed FEP with BaTiO3 increased significantly from 106 to 108 cells/cm3 and the expansion ratio ranged between 4.0 and 5.5. Moreover, a decrease in an abnormal phenomenon that expansion ratio for the pure FEP foam was observed as the saturation pressure increased. This unexpected phenomenon can be explained by the relationship between foaming and crystallization coupling processes.
{"title":"Foaming behavior of the fluorinated ethylene propylene copolymer assisted with supercritical carbon dioxide","authors":"Ziyin Jiang, Yun-fei Zhang, Chang-jing Gong, Zhen Yao, A. Shukla, Kun Cao","doi":"10.1177/0021955X20964003","DOIUrl":"https://doi.org/10.1177/0021955X20964003","url":null,"abstract":"Foaming behavior of the fluorinated ethylene propylene copolymer (FEP) and its composites assisted with supercritical carbon dioxide (scCO2) as the blowing agent were investigated. The batch foaming process was applied at temperature ranging from 250°C to 265°C and pressure ranging between 12 MPa and 24 MPa. The optimal foaming temperature and saturation pressure were obtained for both pure FEP and FEP composites with 1 wt% different-sized BaTiO3 as nucleating agent. The cell diameter of pure FEP foam ranging from 80–140 µm was observed while the cell diameter decreased to 20–40 µm after adding BaTiO3 particles. The cell density of foamed FEP with BaTiO3 increased significantly from 106 to 108 cells/cm3 and the expansion ratio ranged between 4.0 and 5.5. Moreover, a decrease in an abnormal phenomenon that expansion ratio for the pure FEP foam was observed as the saturation pressure increased. This unexpected phenomenon can be explained by the relationship between foaming and crystallization coupling processes.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"41 1","pages":"893 - 909"},"PeriodicalIF":2.5,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77005556","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 : 2020-11-13DOI: 10.1177/0021955X20969553
Xiaoli Zhang, Xihuan Wang, Binbin Dong, G. Zheng, Jingbo Chen, Changyu Shen, Chul B. Park
Crystal nucleating agent Bis (3, 4- dimethylbenzylidene) sorbitol (DMDBS) was used to tune the melt strength and microcellular foaming properties of isotactic polypropylene (iPP) in this study. Rheological testing results reveal that the introduction of DMDBS could enhance the storage modulus and complex viscosity of iPP, obviously increase its crystallization onset temperature, compared to its counterparts without DMDBS. The addition of DMDBS could also significantly increase the cell nucleating ability of iPP, due to its large surface, cooperating with a thermal history control treatment. Quite fine microcellular iPP/DMDBS foams were fabricated with relatively small average cell sizes of nano to several micrometers, and cell densities up to 1011∼1012 cells/cm3, using the synergy effect of DMDBS and iPP’s melt self-enhancement. Under a comparatively low re-saturation pressure of 8 to 12 MPa, ideal microcellular foams could be generated, at a temperature zone of 158 to 162°C, which is slightly below to iPP’s original pellets nominal melting point.
{"title":"Synergetic effect of crystal nucleating agent and melt self-enhancement of isotactic polypropylene on its rheological and microcellular foaming properties","authors":"Xiaoli Zhang, Xihuan Wang, Binbin Dong, G. Zheng, Jingbo Chen, Changyu Shen, Chul B. Park","doi":"10.1177/0021955X20969553","DOIUrl":"https://doi.org/10.1177/0021955X20969553","url":null,"abstract":"Crystal nucleating agent Bis (3, 4- dimethylbenzylidene) sorbitol (DMDBS) was used to tune the melt strength and microcellular foaming properties of isotactic polypropylene (iPP) in this study. Rheological testing results reveal that the introduction of DMDBS could enhance the storage modulus and complex viscosity of iPP, obviously increase its crystallization onset temperature, compared to its counterparts without DMDBS. The addition of DMDBS could also significantly increase the cell nucleating ability of iPP, due to its large surface, cooperating with a thermal history control treatment. Quite fine microcellular iPP/DMDBS foams were fabricated with relatively small average cell sizes of nano to several micrometers, and cell densities up to 1011∼1012 cells/cm3, using the synergy effect of DMDBS and iPP’s melt self-enhancement. Under a comparatively low re-saturation pressure of 8 to 12 MPa, ideal microcellular foams could be generated, at a temperature zone of 158 to 162°C, which is slightly below to iPP’s original pellets nominal melting point.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"18 1","pages":"101 - 121"},"PeriodicalIF":2.5,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83055262","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 : 2020-10-13DOI: 10.1177/0021955X20963989
KB Bhagavathula, JS Parcon, A. Azar, S. Ouellet, S. Satapathy, CR Dennison, JD Hogan
In this work, the authors study the thermo-mechanical response of a dilatant polymeric foam in quasistatic tension and compression, focusing on the links between microstructure, mechanical response, and associated temperature rises in these materials. The authors study these links for a commercially-available shear-thickening foam, named D3O LITE D. Samples were tested under quasi-static conditions for a strain rate of 0.1 s−1 in tension and compression. Micro X-ray computed tomography (XCT) was used to study the evolution of microstructure (pore size and wall thickness) as a function of strain and this was achieved by developing MATLAB-based programs to analyze these microstructural features. The foam specimens were loaded until failure which allowed for the investigation of the elastic, inelastic, and failure regimes. From the XCT images, pore stretching and cell wall tearing are observed in tension, and buckling and pore collapse are observed in compression. These mechanisms are studied in-situ using an infrared thermal camera which record temperature profiles, and temperature measurements are linked back to stress-strain, and temperature-strain responses. For this material, the tensile yield stress was 0.57 ± 0.10 MPa and the elastic modulus was 5.47 ± 0.10 MPa respectively, at a yield strain of 0.10 ± 0.04. At the time of failure, the average temperature of the specimen was found to increase by ∼3.00°C and a local temperature increase of ∼8.00°C was observed in the failure region. In compression, the elastic collapse stress and elastic modulus were found to be 0.130 ± 0.016 MPa and 2.5 ± 0.2 MPa, respectively. The temperature increase in compression at ∼0.83 strain was ∼0.65°C. These results represent some of the first mechanical properties on shear-thickening foams in the literature, and the discoveries on the linkages between the microstructure and the mechanical properties in this study are important for researchers in materials design and modelling.
{"title":"Quasistatic response of a shear-thickening foam: Microstructure evolution and infrared thermography","authors":"KB Bhagavathula, JS Parcon, A. Azar, S. Ouellet, S. Satapathy, CR Dennison, JD Hogan","doi":"10.1177/0021955X20963989","DOIUrl":"https://doi.org/10.1177/0021955X20963989","url":null,"abstract":"In this work, the authors study the thermo-mechanical response of a dilatant polymeric foam in quasistatic tension and compression, focusing on the links between microstructure, mechanical response, and associated temperature rises in these materials. The authors study these links for a commercially-available shear-thickening foam, named D3O LITE D. Samples were tested under quasi-static conditions for a strain rate of 0.1 s−1 in tension and compression. Micro X-ray computed tomography (XCT) was used to study the evolution of microstructure (pore size and wall thickness) as a function of strain and this was achieved by developing MATLAB-based programs to analyze these microstructural features. The foam specimens were loaded until failure which allowed for the investigation of the elastic, inelastic, and failure regimes. From the XCT images, pore stretching and cell wall tearing are observed in tension, and buckling and pore collapse are observed in compression. These mechanisms are studied in-situ using an infrared thermal camera which record temperature profiles, and temperature measurements are linked back to stress-strain, and temperature-strain responses. For this material, the tensile yield stress was 0.57 ± 0.10 MPa and the elastic modulus was 5.47 ± 0.10 MPa respectively, at a yield strain of 0.10 ± 0.04. At the time of failure, the average temperature of the specimen was found to increase by ∼3.00°C and a local temperature increase of ∼8.00°C was observed in the failure region. In compression, the elastic collapse stress and elastic modulus were found to be 0.130 ± 0.016 MPa and 2.5 ± 0.2 MPa, respectively. The temperature increase in compression at ∼0.83 strain was ∼0.65°C. These results represent some of the first mechanical properties on shear-thickening foams in the literature, and the discoveries on the linkages between the microstructure and the mechanical properties in this study are important for researchers in materials design and modelling.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"139 1","pages":"863 - 892"},"PeriodicalIF":2.5,"publicationDate":"2020-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76348389","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 : 2020-10-13DOI: 10.1177/0021955X20965216
S. K. Bhudolia, Goram Gohel, K. Leong
Expanded Polystyrene (EPS) is commonly used as an inner liner for a bicycle helmet due to its outstanding energy absorption characteristic and light-weight property. The current investigation presents a novel technique to manufacture hybrid EPS/honeycomb structure foam using an integrated manufacturing approach to further enhance the energy dissipation properties for improved safety against head injuries. Different foam designs were analysed under curb-stone impact tests and the failure mechanisms are deliberated. Integrated EPS-honeycomb hybrid liners have shown up to 20% higher energy absorption, with the additional energy being absorbed in associated densification of foam and the elastic buckling features of the honeycomb.
{"title":"Enhanced energy absorption characteristics of novel integrated hybrid honeycomb/polystyrene foam","authors":"S. K. Bhudolia, Goram Gohel, K. Leong","doi":"10.1177/0021955X20965216","DOIUrl":"https://doi.org/10.1177/0021955X20965216","url":null,"abstract":"Expanded Polystyrene (EPS) is commonly used as an inner liner for a bicycle helmet due to its outstanding energy absorption characteristic and light-weight property. The current investigation presents a novel technique to manufacture hybrid EPS/honeycomb structure foam using an integrated manufacturing approach to further enhance the energy dissipation properties for improved safety against head injuries. Different foam designs were analysed under curb-stone impact tests and the failure mechanisms are deliberated. Integrated EPS-honeycomb hybrid liners have shown up to 20% higher energy absorption, with the additional energy being absorbed in associated densification of foam and the elastic buckling features of the honeycomb.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"12 1","pages":"839 - 848"},"PeriodicalIF":2.5,"publicationDate":"2020-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87580089","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 : 2020-10-13DOI: 10.1177/0021955X20965215
S. K. Bhudolia, Goram Gohel, K. Leong
Expanded Polystyrene (EPS) is a common material used to manufacture the inner foam liner of a bicycle helmet due to its outstanding energy absorption characteristics and light-weight property. The current research presents a novel corrugated expanded polystyrene (EPS) foam design concept which is used to enhance the impact dissipation of bicycle helmets from the safety standpoint to reduce head injuries and make them lighter. The baseline comparison study under impact for different foam configurations is compared with a conventional EPS foam sample without corrugation. Corrugated foam designs under current investigation are 12.5–20% lighter and provide up to 10% higher energy absorption. The details of the novel manufacturing concept, CPSC 1203 helmet impact tests, high-speed camera study to understand the differences in the failure mechanisms are deliberated in this paper.
{"title":"Impact performance of innovative corrugated polystyrene foam for bicycle helmets","authors":"S. K. Bhudolia, Goram Gohel, K. Leong","doi":"10.1177/0021955X20965215","DOIUrl":"https://doi.org/10.1177/0021955X20965215","url":null,"abstract":"Expanded Polystyrene (EPS) is a common material used to manufacture the inner foam liner of a bicycle helmet due to its outstanding energy absorption characteristics and light-weight property. The current research presents a novel corrugated expanded polystyrene (EPS) foam design concept which is used to enhance the impact dissipation of bicycle helmets from the safety standpoint to reduce head injuries and make them lighter. The baseline comparison study under impact for different foam configurations is compared with a conventional EPS foam sample without corrugation. Corrugated foam designs under current investigation are 12.5–20% lighter and provide up to 10% higher energy absorption. The details of the novel manufacturing concept, CPSC 1203 helmet impact tests, high-speed camera study to understand the differences in the failure mechanisms are deliberated in this paper.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"57 1","pages":"849 - 862"},"PeriodicalIF":2.5,"publicationDate":"2020-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88426532","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 : 2020-10-12DOI: 10.1177/0021955X20964018
E. F. Kerche, R. Delucis, C. Petzhold, S. Amico
Rigid polyurethane biofoams (RPUF) were produced by single shot-method using a bio-based polyol and 10 wt% of pinewood particles. Two different confinement degrees were investigated (70% and 50% of the free-rising volume), along with a control group produced under free-rising. RPUF were studied using SEM images (to estimate average foam cell size and anisotropy index), mechanical testing (under compression and tension), apparent density, and thermal conductivity analysis. The results were statistically evaluated using ANOVA tests prior to means tests. The RPUF produced under confinement showed more rounded and homogeneous cell structures compared to those freely expanded. The filled RPUF produced under a confinement degree of 50% yielded very high compressive and tensile strengths, whereas thermal conductivity decreased with confinement.
{"title":"Rigid bio-based wood/polyurethane foam composites expanded under confinement","authors":"E. F. Kerche, R. Delucis, C. Petzhold, S. Amico","doi":"10.1177/0021955X20964018","DOIUrl":"https://doi.org/10.1177/0021955X20964018","url":null,"abstract":"Rigid polyurethane biofoams (RPUF) were produced by single shot-method using a bio-based polyol and 10 wt% of pinewood particles. Two different confinement degrees were investigated (70% and 50% of the free-rising volume), along with a control group produced under free-rising. RPUF were studied using SEM images (to estimate average foam cell size and anisotropy index), mechanical testing (under compression and tension), apparent density, and thermal conductivity analysis. The results were statistically evaluated using ANOVA tests prior to means tests. The RPUF produced under confinement showed more rounded and homogeneous cell structures compared to those freely expanded. The filled RPUF produced under a confinement degree of 50% yielded very high compressive and tensile strengths, whereas thermal conductivity decreased with confinement.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"35 1","pages":"757 - 768"},"PeriodicalIF":2.5,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83848158","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 : 2020-10-06DOI: 10.1177/0021955X20943101
FA Almeida, H. Beyrichen, N. Dodamani, R. Caps, A. Müller, R. Oberhoffer
New polystyrene (PS) foams with submicron pore sizes and open pore structure are introduced as potential cores for vacuum insulation panels (VIPs). Measurements of the thermal conductivity λ of the air-filled and evacuated PS foams, the influence of temperature T, opacifiers as well as gas pressure p on the thermal conductivity λ are presented. First results of the foam microstructures, as visualized by electron microscopy, confirm that pore sizes below 1 µm can be achieved. Thermal conductivity values of advanced samples in vacuum of about 7 mW/(m·K) were measured.
{"title":"Thermal conductivity analysis of a new sub-micron sized polystyrene foam","authors":"FA Almeida, H. Beyrichen, N. Dodamani, R. Caps, A. Müller, R. Oberhoffer","doi":"10.1177/0021955X20943101","DOIUrl":"https://doi.org/10.1177/0021955X20943101","url":null,"abstract":"New polystyrene (PS) foams with submicron pore sizes and open pore structure are introduced as potential cores for vacuum insulation panels (VIPs). Measurements of the thermal conductivity λ of the air-filled and evacuated PS foams, the influence of temperature T, opacifiers as well as gas pressure p on the thermal conductivity λ are presented. First results of the foam microstructures, as visualized by electron microscopy, confirm that pore sizes below 1 µm can be achieved. Thermal conductivity values of advanced samples in vacuum of about 7 mW/(m·K) were measured.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"416 1","pages":"493 - 515"},"PeriodicalIF":2.5,"publicationDate":"2020-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78779108","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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