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ASTM D1667-2017 软质多孔材料-氯乙烯聚合物和共聚物(闭孔泡沫)规格 Standard Specification for Flexible Cellular Materials—Poly (Vinyl Chloride) Foam (Closed-Cell)
1.1 This specification covers flexible closed-cell or non-interconnecting cellular products, the elastomer content of which is predominantly poly(vinyl chloride) or copolymers thereof. 1.2 In the case of conflict between the provisions of this specification and those of detailed specifications or methods of test for a particular product, the latter shall take precedence. 1.3 Reference to the methods for testing closed-cell poly(vinyl chloride) contained herein shall specifically state the particular test or tests desired and not refer to these methods of test as a whole. 1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only. 1.5 The following precautionary statement pertains to the test method portions only of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Note 1: There is no known ISO equivalent to this standard....
2023-08-14 17:48:01浏览：21
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HG/T 5403-2018 镁钛系乙烯聚合催化剂化学成分分析方法 Analytical method of chemical composition for Mg-Ti based ethylene polymerization catalyst
本标准规定了镁钛系乙烯聚合催化剂化学成分分析方法。<br />本标准适用于镁VC系乙烯聚合催化剂中镁（Mg)、钛(Ti)、铝（Al)、(Cl)、四氢呋喃(THF)、钒（V）和固含量质量分数的测定。...
2023-08-11 08:48:01浏览：30
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支化聚乙烯的合成及结构与性能
以[ArN=C(An)-C(An)=NAr] NiBr2[An=acenaphthyl,Ar=2,6-C6H3(iPr)2]为主催化剂,以改性甲基铝氧烷(MMAO)和常规的甲基铝氧烷(MAO)为助催化剂,研究了压力、温度和时间等条件对乙烯聚合制备支化聚乙烯的影响,采用高温核磁、高温凝胶渗透色谱(GPC)及差示扫描量热仪(DSC)等对所得的聚乙烯结构进行表征.研究发现,以MMAO为助催化剂时,催化活性比以MAO为助催化剂时高约1个数量级,达到107 g/(mol Ni·h);所得聚乙烯的支化度为(45～64)/1000C,而以MAO为助催化剂时所得聚乙烯的支化度达(82～ 88)/1000C.对支化聚乙烯的力学性能进行了分析,并与低密度聚乙烯(LDPE)和二元乙丙橡胶(EPM)进行比较.结果表明,支化聚乙烯拉伸强度达27.90 MPa,比LDPE(14.40 MPa)和EPM (5.44 MPa)高,但支化聚乙烯的弹性模量仅为2.10 MPa,与EPM(2.11 MPa)相近;支化聚乙烯的断裂伸长率为774.6％,略高于LDPE的断裂伸长率(725.6％),比EPM的断裂伸长率(1770.1％)低....
2020-09-28 16:47:12浏览：65
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含Ti-Mg-Al配合物的催化剂合成及催化烯烃聚合
合成了一种新型含Ti-Mg-Al配合物(MTA)的聚烯烃催化剂,研究了它的结构及其催化乙烯均聚合及乙烯与1-己烯共聚合的性能.在常压、均相聚合条件下,MTA催化乙烯聚合具有较高的活性,可达2.14×105 g/(mol*h).MTA在催化乙烯与1-己烯共聚合时,具有良好的聚合活性.通过改变共聚单体的浓度,可有效调节聚合物的熔点、1-己烯的插入率、相对分子质量及其分布....
2020-06-12 16:09:21浏览：1406
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茂锆金属催化剂催化乙烯聚合研究
主要考察了含锆的茂金属催化剂中催化乙烯反应条件优化研究,在最优条件下催化聚合反应所得的产物与吉林石化公司聚乙烯厂聚乙烯产品进行分析对比.对茂锆金属催化剂催化乙烯聚合反应条件研究表明,适宜的助催化剂[Al]与主催化剂[Cat]的摩尔比在1 500左右,适宜的主催化剂浓度在1.5×10-4 mol/L左右,最佳聚合温度60℃,此时催化剂的活性可达到106 gPE/(molCat·h).从物理性能、热性能、相对支化度、相对分子质量及其分布分析可知,制备出的负载茂锆金属催化剂在最优反应条件下催化乙烯聚合所得的产物与吉林石化公司聚乙烯产品性质基本一致,符合产品的指标,支链分布均匀,分子量分布更窄.同时对茂锆金属催化剂主、助催化剂催化乙烯聚合的作用和机理进行了探讨....
2020-06-12 16:09:20浏览：1428
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