Cellular Polymers最新文献_第7页

Preparation and performance of melamine-formaldehyde rigid foams with high closed cell content 高闭孔含量三聚氰胺甲醛硬质泡沫塑料的制备及性能

IF 1.6 4区医学

Cellular Polymers Pub Date : 2021-05-17 DOI: 10.1177/02624893211017130

Chunhui Li, Haihong Ma, Cong Song, Zhengfa Zhou, Weibing Xu, Qiusheng Song, F. Ren

{"title":"Preparation and performance of melamine-formaldehyde rigid foams with high closed cell content","authors":"Chunhui Li, Haihong Ma, Cong Song, Zhengfa Zhou, Weibing Xu, Qiusheng Song, F. Ren","doi":"10.1177/02624893211017130","DOIUrl":"https://doi.org/10.1177/02624893211017130","url":null,"abstract":"Melamine-formaldehyde (MF)rigid foams with high closed cell content were prepared via oven heating process, using MF prepolymer prepared from melamine and paraformaldehyde as a matrix, cyclohexane as the foaming agent, dimethyl silicon oil as the foam stabilizers, hydrochloric acid as the catalyst. The effect of MF prepolymer viscosity, foaming temperature, amount of catalyst on morphology, closed cell content, apparent density, water absorption and compressive strength of MF rigid foams were systematically studied. The optimized foaming conditions are as follows: the viscosity of MF prepolymer ranges from 35 Pa·s to 45 Pa·s, the foaming temperature is 125°C and the content of the catalyst is 0.65 wt%. The as-prepared MF foams showed the best comprehensive performance with closed cell content of 83.5%, apparent density of 62 kg·m−3, water absorption of 12.0%, compressive strength of 292kPa, thermal conductivity of 0.033 W m−1 K−1 and limiting oxygen index (LOI) of 36%. Compared to conventional organic foams, MF rigid foams possess low water absorption, excellent thermal insulation and flame retardancy due to high closed cell content, and can be expected to be used as thermal insulation material for building exterior walls.","PeriodicalId":9816,"journal":{"name":"Cellular Polymers","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/02624893211017130","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49442641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Effect of multi-walled carbon nanotubes with different diameters on morphology and thermal and mechanical properties of flexible polyurethane foams 不同直径的多壁碳纳米管对柔性聚氨酯泡沫形态及热力学性能的影响

IF 1.6 4区医学

Cellular Polymers Pub Date : 2021-05-13 DOI: 10.1177/02624893211017284

Fukai Yang, Miao Xie, Zhang Yudi, Xinyu Xu

{"title":"Effect of multi-walled carbon nanotubes with different diameters on morphology and thermal and mechanical properties of flexible polyurethane foams","authors":"Fukai Yang, Miao Xie, Zhang Yudi, Xinyu Xu","doi":"10.1177/02624893211017284","DOIUrl":"https://doi.org/10.1177/02624893211017284","url":null,"abstract":"We report flexible polyurethane foams (PUFs) containing –OH functionalized multi-walled carbon nanotubes (MWCNTs) with different diameters (10–20 nm, 20–30 nm, >50 nm) from 0.1–0.6 wt% (per 100 resins of polyol by weight) prepared via in situ polymerization. After synthesis, the morphology of the MWCNT/PUF composites was observed through scanning electron microscopy (SEM) based on MWCNT amount. The MWCNTs acted as nucleating agents and increased the matrix viscosity. The pore size of the composites decreased and the number of pores increased with increasing MWCNT concentration. Dynamic mechanical analysis (DMA) showed that the storage modulus of the composites increased, the loss modulus decreased, and the Tg gradually decreased with increasing MWCNT content. The incorporation of MWCNTs induced remarkable thermal stabilization of the matrix. The increase in the degradation temperature from 294°C to 304°C resulted in a 50% weight loss. The mechanical properties of the MWCNT/PUF materials increased with increasing MWCNT proportion because of the excellent compatibility and strong interface interaction between the MWCNT and flexible PUF.","PeriodicalId":9816,"journal":{"name":"Cellular Polymers","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/02624893211017284","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44908253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Characterization of microstructures of SAN foam core using micro-computed tomography 用微计算机断层扫描表征SAN泡沫芯的微结构

IF 1.6 4区医学

Cellular Polymers Pub Date : 2021-04-05 DOI: 10.1177/02624893211006879

Youming Chen, R. Das, Hui Wang, M. Battley

{"title":"Characterization of microstructures of SAN foam core using micro-computed tomography","authors":"Youming Chen, R. Das, Hui Wang, M. Battley","doi":"10.1177/02624893211006879","DOIUrl":"https://doi.org/10.1177/02624893211006879","url":null,"abstract":"In this study, the microstructure of a SAN foam was imaged using a micro-CT scanner. Through image processing and analysis, variations in density, cell wall thickness and cell size in the foam were quantitatively explored. It is found that cells in the foam are not elongated in the thickness (or rise) direction of foam sheets, but rather equiaxed. Cell walls in the foam are significantly straight. Density, cell size and cell wall thickness all vary along the thickness direction of foam sheets. The low density in the vicinity of one face of foam sheets leads to low compressive stiffness and strength, resulting in the strain localization observed in our previous compressive tests. For M80, large open cells on the top face of foam sheets are likely to buckle in compressive tests, therefore being another potential contributor to the strain localization as well. The average cell wall thickness measured from 2D slice images is around 1.4 times that measured from 3D images, and the average cell size measured from 2D slice images is about 13.8% smaller than that measured from 3D images. The dispersions of cell wall thickness measured from 2D slice images are 1.16–1.20 times those measured from 3D images. The dispersions of cell size measured from 2D slice images are 1.12–1.36 times those measured from 3D images.","PeriodicalId":9816,"journal":{"name":"Cellular Polymers","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/02624893211006879","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42885065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Influence of carbon nanotubes on the properties of biopolyol based polyurethane foams 碳纳米管对生物多元醇基聚氨酯泡沫性能的影响

IF 1.6 4区医学

Cellular Polymers Pub Date : 2021-03-01 DOI: 10.1177/0262489321989005

Rujuta Dhoke, A. Ojha, A. Chaudhary, R. Vijayakumar

{"title":"Influence of carbon nanotubes on the properties of biopolyol based polyurethane foams","authors":"Rujuta Dhoke, A. Ojha, A. Chaudhary, R. Vijayakumar","doi":"10.1177/0262489321989005","DOIUrl":"https://doi.org/10.1177/0262489321989005","url":null,"abstract":"Biopolyols were obtained from liquefaction of sugarcane bagasse and rice husk. Acid and hydroxyl numbers were determined for estimating the polyol value of the liquid products. These prepared biopolyols were mixed with the commercial polyol for the preparation of polyurethane foam (PU). To study the effects of biopolyol on properties of PU foam, various ratios of biopolyol to commercial polyol were used. It was observed that the density and foaming time of the PU foam increases with the increase in biopolyol content. The calculated Isocyanate index showed that sugarcane bagasse polyol can be used to make flexible foam and that rice husk can be used to make rigid foam. Foaming times and full rise times increased with increase in the biopolyol content. The Fourier-transform infrared spectroscopy (FTIR) spectra of prepared foams showed the characteristic peaks related to PU foam. The morphological studies were carried out using scanning electron microscopy (SEM). Thermal conductivity tests proved that the synthesized PU foams can be used as insulating materials. Further, PU foams were also prepared with the incorporation of carbon nanotubes (CNTs) in the polyol. The densities, thermal conductivities and SEM analysis of PU foams with and without carbon nanotubes were compared.","PeriodicalId":9816,"journal":{"name":"Cellular Polymers","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0262489321989005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45731584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Improvement of thermal conductivity of rigid polyurethane foams with aluminum nitride filler 氮化铝填料对硬质聚氨酯泡沫塑料导热性能的改善

IF 1.6 4区医学

Cellular Polymers Pub Date : 2021-03-01 DOI: 10.1177/0262489321988970

Serife Akkoyun, Meral Akkoyun

引用次数: 6

An in vitro evaluation on polyurethane foam sheets of the insertion torque, removal torque values, and resonance frequency analysis (RFA) of a self-tapping threads and round apex implant 聚氨酯泡沫片对自攻螺纹和圆顶端植入物插入扭矩、移除扭矩值和共振频率分析（RFA）的体外评估

IF 1.6 4区医学

Cellular Polymers Pub Date : 2020-11-25 DOI: 10.1177/0262489320971796

M. Tumedei, A. Piattelli, A. Falco, F. de Angelis, F. Lorusso, M. Di Carmine, G. Iezzi

引用次数: 8

Foaming behavior of 1-vinyl-2-pyrrolidone–methyl methacrylate copolymers under ScCO2 1-乙烯基-2-吡咯烷酮-甲基丙烯酸甲酯共聚物在ScCO2下的发泡行为

IF 1.6 4区医学

Cellular Polymers Pub Date : 2020-08-04 DOI: 10.1177/0262489320929226

Miriam Trigo-lopez, José A. Reglero Ruiz, Saúl Vallejos, C. Ramos, S. Beltrán, F. García, J. García

引用次数: 1

Morphological evaluation of ultralow density microcellular foamed composites developed through CO2-induced solid-state batch foaming technique utilizing water as co-blowing agent 以水为共发泡剂，采用co2诱导固态间歇发泡技术制备的超低密度微孔泡沫复合材料的形态评价

IF 1.6 4区医学

Cellular Polymers Pub Date : 2020-07-01 DOI: 10.1177/0262489319897633

Rupesh Dugad, G. Radhakrishna, A. Gandhi

引用次数: 8

Achievements and prospects for the synthesis of poly(meth)acrylimide foams. Stage of the thermal imidisation of polymer precursors 聚（甲基）丙烯酰亚胺泡沫合成的成就与展望。聚合物前体的热酰亚胺化阶段

IF 1.6 4区医学

Cellular Polymers Pub Date : 2020-07-01 DOI: 10.1177/0262489320934258

O. Kazantsev, K. V. Shirshin, P. V. Kornienko, A. P. Sivokhin

引用次数: 2

Thermal conductivity and conditioning of grey expanded polystyrene foams 灰色发泡聚苯乙烯泡沫的导热性和热处理

IF 1.6 4区医学

Cellular Polymers Pub Date : 2020-06-26 DOI: 10.1177/0262489320934263

A. Simpson, Ig Rattigan, E. Kalavsky, G. Parr

{"title":"Thermal conductivity and conditioning of grey expanded polystyrene foams","authors":"A. Simpson, Ig Rattigan, E. Kalavsky, G. Parr","doi":"10.1177/0262489320934263","DOIUrl":"https://doi.org/10.1177/0262489320934263","url":null,"abstract":"This article focuses on the thermal conductivity of 50 mm thick silver grey (infrared absorbing) expanded polystyrene (EPS) foam boards blown with pentane. The effect of short-term ageing from the point of production, by ambient conditioning at 23°C/50% RH, is compared to conditioning at an elevated temperature of 70°C. The declared thermal properties of the product and CE certification are fulfilled by the requirements of the European EPS product standard and SG19 Guidance. Measured thermal conductivity levels within 1% of the final value are acceptable and considered representative throughout the economic life of the product. Levels within the criteria were determined for 50 mm silver EPS after conditioning for 5 days at an elevated temperature of 70°C, whereas for conditioning at 23°C/50% RH the time taken was 23 days. The latter time is in good accord with retesting retained grey EPS boards of similar density and up to 9 years old, after initial testing 22 days from production, and conditioning at 23°C/50% RH. Elevated temperature conditioning increases the rate of diffusion of the blowing agent, but there has been concern about EPS beads softening above 60°C. Although there is little evidence from scanning electron microscopy of significant increase in perforation of the cell membranes at elevated temperatures, there is some indication of a small increase in wrinkling of the walls and intercell skeletal strands at 60°C and 70°C. It takes longer to eliminate the pentane gas by conditioning at 23°C/50% RH but there is no risk of material change from heat conditioning.","PeriodicalId":9816,"journal":{"name":"Cellular Polymers","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0262489320934263","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46025099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14