共查询到20条相似文献,搜索用时 421 毫秒
1.
2.
采用高聚合度PVC(HPVC)制得了弹性体,比较了HPVC弹性体与NBR/PVC弹性体的压缩永久变形率,并针对试验配方在成品加工与应用中的问题进行了讨论。结果表明:1HPVC可以替代NBR/PVC用于制备弹性体,且弹性更好、成本更低;2HPVC粒料的加工温度比NBR/PVC粒料高15~20℃,且加工温度范围更窄,导致新用户在调试时难度更大;3HPVC粒料适合用于生产挤出制品和对表面质量要求不高的注塑制品。 相似文献
3.
本文采用零长毛细管流变仪测量了不同助剂对PVC复合物在滚压过程中凝胶度的影响及其与性能的关系。结果表明:在本实验条件下,随加工温度的升高,体系凝胶度增大,共混体的性能也逐渐改善。对PVC/ACR—201和PVC/AS体系,在加工温度(Tp)为180℃时,凝胶含量为80~95%时(Tt=160℃,W=120kg),其综合性能最佳。 相似文献
4.
高聚合度聚氯乙烯树脂及其加工、改性的研究进展 总被引:3,自引:0,他引:3
高聚合度聚氯乙烯(HPVC)树脂是一种机械力学性能优异的新一代聚氯乙烯(PVC)树脂,文中叙述了HPVC的合成工艺方法,加工工艺条件;介绍了HPVC的机械力学性能,耐热性,高弹性等,并探讨了相关的结构与性能的关系;例举了各种高分子改性剂对HPVC的改性研究,并对此进行了展望。 相似文献
5.
聚氯乙烯热塑性弹性体的开发与应用 总被引:1,自引:0,他引:1
本文叙述了PVC—TPE的性能和用途,介绍了该厂生产的高聚合度(聚合度在2500~4000)各种规格的HPVC树脂的性能及105℃级耐热电缆用粒料、鞋用高弹粒料和软管用、密封条等多个品种粒料的性能。并指出用HPVC树脂开发出的PVC—TPE是一种用途广泛、物美价廉的新材料。 相似文献
6.
HPVC/NBR非硫化共混材料性能与工艺研究 总被引:3,自引:1,他引:2
文中研究了以高聚合度聚氯乙烯(HPVC聚合度P=2500)为主体材料,利用下腈橡胶(NBR)改性的非硫化熔融共混工艺,结果发现,当共混比HPVC/NBR=100:25,共混温度在160~180℃,混炼时间6~10min时,能得到性能良好的共混材料,尤其改善了材料的恒定压缩永久变形与冲击回弹。 相似文献
7.
PVC树脂粉末在一定温度和剪切力作用下发生凝胶化是硬质PVC在挤出成型加工中的基本行为之一,凝胶程度和凝胶速度对硬质PVC管的质量控制,提高生产效率起着关键作用。实验结果表明,PVC的凝胶程度控制在60~70%之间,能够生产出综合性能最佳的高质量管子。PVC挤出成型期间发生的凝胶作用与其高温粘弹性密切相关。利用流变仪测定粘弹性,是迄今测定凝胶度的较理想方法。PVC的凝胶化不仅影响塑料制品的外观和物化性能,对加工能力也有很大影响。在PVC配合料中掺混高分子加工助剂ACR,能有效地促进PVC凝胶化,明显提高硬质PVC管的质量指标。 相似文献
8.
9.
高聚合度聚氯乙烯的光热稳定性 总被引:1,自引:0,他引:1
主要研究了高聚合度聚氯乙烯(HPVC)的热稳定性和热分解过程以及光老化对HPVC性能的影响。结果表明,聚合度越高,树脂的热稳定性越好,HPVC的耐光老化性能明显优于普通聚合度聚氯乙烯(PVC)。 相似文献
10.
11.
乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
13.
14.
The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
15.
D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
16.
17.
Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
18.
塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献
19.
20.