共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
采用模压一步法制备EPDM海绵。研究发泡剂品种和用量对其性能的影响。结果表明,以发泡剂AC,OBSH或H制备EPDM海绵,最佳用量分别为5,5和3份;发泡剂用量为5份时,以发泡剂H制备的EPDM海绵发泡倍率最大。以发泡剂AC/OBSH,AC/H或OBSH/H并用制备EPDM海绵,最佳并用量分别为5,4和2份;发泡剂并用量为5份时,以发泡剂AC/OBSH并用制备的EPDM海绵发泡倍率最大。扫描电子显微镜观察发现.以发泡剂AC/OBSH井用制备的EPDM海绵微孔分散均匀。 相似文献
4.
5.
天然橡胶发泡材料的压缩行为与能量吸收特性 总被引:1,自引:0,他引:1
用发泡剂N,N′-二亚硝基五次甲基四胺(简称发泡剂H)制备了天然橡胶(NR)发泡材料,研究了不同密度的NR发泡材料的压缩行为和能量吸收特性。结果表明,随着发泡剂H用量的增加,NR发泡材料的密度与硬度均降低;NR发泡材料的压缩应力-应变曲线有2个阶段:线性弹性阶段和致密化阶段;随着发泡材料密度的减小,线性弹性区变宽,相对弹性模量降低。在应力较小的时候,密度小的NR发泡材料吸收能量较多,在应力较高的时候,密度大的NR发泡材料吸收能量多。随着发泡材料密度的减小,其吸能效率最大值与理想参数最大值提高。 相似文献
6.
该文阐述了含有双环戊二烯的EPDM与有机过氧化物、有机发泡剂配合,制成发泡倍率为3.0的EPDM高倍发泡海绵制品.该发泡海绵耐热性优异.发泡倍率高,交联、发泡时的预热时间大为缩短. 相似文献
7.
9.
采用热空气自由发泡制备EPDM海绵,研究发泡剂品种和用量对其性能的影响。结果表明,以发泡剂AC、OBSH和H制备EPDM海绵,最佳用量分别为15、10和10份;当发泡剂用量为10份时,以发泡剂OBSH制备的EPDM海绵发泡倍率最大。 相似文献
10.
11.
12.
通过对不同配方的混炼胶门尼粘度、发泡剂用量与所得发泡橡胶微孔尺寸及微孔间隙关系的分析,讨论了加工工艺对天然及丁腈发泡橡胶结构的影响。其中混炼胶的门尼粘度对发泡橡胶尺寸的影响有较强的规律。发泡橡胶微孔单元内外压差与尺寸的关系和这一规律有很大的相似性。为调节工艺来获得所需结构的发泡橡胶提供了一种可行的方法。 相似文献
13.
14.
以碱性蛋白酶催化水解明胶制备了发泡剂母液,并与十二烷基苯磺酸钠和脂肪醇聚氧乙烯醚硫酸钠复配,制得多种新型蛋白基发泡剂。基于气泡指标对这些发泡剂进行初选,并利用初选后的发泡剂制备气泡混合轻质土试样,测定了试样的密度。结合气泡性能指标和试样密度确定的性能最优的发泡剂配方是自制发泡剂F-6(明胶10%、十二烷基苯磺酸钠11.4%、脂肪醇聚氧乙烯醚硫酸钠12.6%)和F-7(明胶10%、十二烷基苯磺酸钠7.8%、脂肪醇聚氧乙烯醚硫酸钠15.4%)。这两种发泡剂的1 h消泡占比分别为52.52%和53.18%,发泡倍数分别为82.61和81.66,综合性能优于一般市售发泡剂,且制出的试样密度较小,强度可达4MPa,完全满足工程要求。 相似文献
15.
Rubber compounds based on natural rubber (NR) reinforced with octadecylamine‐modified bentonite have been prepared via a vulcanization process and characterized by several techniques. The silicate nanolayers are exfoliated and uniformly dispersed in the polymer chains. Monsanto measurements have shown that the organoclay accelerates the vulcanization reaction and, furthermore, gives rise to a marked increase of the torque, indicating that the elastomer becomes more crosslinked in the presence of the organoclay. These results were corrobated by swelling measurements since a noticeable increase in the curing degree was observed when the organoclay was added to the rubber recipe. Moreover, thermodynamic parameters have shown an increase in the structural order of the nanocomposite. In addition, thermal analysis supports the assumption that the degree of curing of the elastomer increases when the organoclay is added to the elastomer. An appreciable increase of the involved heat during the curing reaction has been observed. Moreover, the Tg of the NR increases in the presence of the organoclay due to the confinement of the elastomer segment into the organoclay nanolayers, which restricts the mobility of the chains. Copyright © 2003 Society of Chemical Industry 相似文献
16.
以猪蹄甲为原料制备发泡液。采用响应面法对影响猪蹄甲角蛋白发泡液泡沫稳泡时间的4个主要影响因素(亚硫酸氢钠质量浓度、反应温度、反应时间、反应体系pH)进行优化,结果表明,当亚硫酸氢钠质量浓度37.06 g/L、水解温度75.4℃、水解时间6.06 h、反应体系pH=5.54时,稳泡时间最大,最大预测值32.18 h,实际测得平均稳泡时间为32 h,与模型理论预测值相比相对误差在0.57%,所以采用响应面法优化得到的参数准确可靠,具有实用价值。 相似文献
17.
The effects of pH value of reaction system, reaction time, reaction temperature, bromine concentration, and amount of potassium persulfate on the bromination reaction in the preparation of brominated natural rubber (BNR) from natural rubber latex were discussed. It has been found from the thermal analysis, that is, the thermal degradation of BNR in nitrogen is a two‐step reaction, and 16% carbonide with a stable structure remained at 470–650°C. The thermo‐oxidative degradation of BNR in air is also a two‐step reaction, and the percentage of degraded BNR reaches to nearly 100% at 600°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
18.
A solid-state chemical reaction occurs when a solvent cast film of a blend of masticated natural rubber and chlorinated natural rubber is heated in the presence of air at 150°C. The thermal behavior of solvent cast films of chlorinated natural rubber, masticated natural rubber, and a 1 : 1 w/w blend (2% w/v in xylene) of these two polymers has been studied using differential scanning calorimetry, infrared spectroscopy, scanning electron microscopy, and nuclear magnetic spectroscopy. The results suggest that carbonyl groups are incorporated into the blend on heating and that the vinyl functionality of the isoprene units is modified during this apparent oxidation. Heating for 2 h at 150°C results in a material that no longer contains the rubber-like cis-1,4-polyisoprene units. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1379–1384, 1997 相似文献
19.
N. Hinchiranan W. Lertweerasirikun W. Poonsawad G. L. Rempel P. Prasassarakich 《应用聚合物科学杂志》2009,111(6):2813-2821
The cure characteristics and mechanical properties of blends consisting of hydrogenated natural rubber (HNR) and natural rubber (NR) blends were investigated. The HNR/NR blends at 50/50 wt ratio were vulcanized using various cure systems: peroxide vulcanization, conventional vulcanization with peroxide, and efficient vulcanization with peroxide. The HNR/NR vulcanizates cured by the combination of peroxide and sulfur donor (tetramethylthiuram disulfide, TMTD) in the efficient vulcanization with peroxide exhibited the best mechanical properties. It was also found that the hydrogenation level of HNR did not affect the tensile strength of the vulcanizates. The tensile strength of the blends decreased with increasing HNR content because of the higher incompatibility to cause the noncoherency behavior between NR and HNR. However, the HNR/NR vulcanizate at 50/50 wt ratio showed the maximum ultimate elongation corresponding to a co‐continuous morphology as attested to by scanning electron micrographs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
20.
Effect of non‐rubber components on vulcanization kinetics of natural rubber was studied with the use of a Rheometer MDR‐2000. The results show that the rate constants of induction period and curing period of natural rubber (NR) are greater than that of natural rubber extracted with acetone (NRE), and the activation energies of induction period and curing period of NR are lower than that of NRE. The activation energy of induction period of NR is reduced by16.9% and the activation energy of curing period of NR is reduced by 3.2% compared to the activation energies of NRE. The time tdis of NR is shorter than that of NRE at the same temperature. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献