共查询到19条相似文献,搜索用时 78 毫秒
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CPVC羧酸型离聚体的合成以及性能研究 总被引:1,自引:0,他引:1
采用氯化原位接枝制备的氯化聚氯乙烯接枝丙烯酸(CPVC-g-AA)与Al(OH)3中和,制备羧酸型离聚体.将离聚体纯化后进行傅立叶变换红外光谱(FT-IR)和差示扫描量热仪(DSC)分析,并进行动态机械分析(DMA)测试,讨论了离聚体力学性能和溶胀性能.结果表明,FT-IR谱图显示出现了新的离子特征吸收峰;离聚体的玻璃化转变温度比CPVC-g-AA的有很大提高;Al离子含量和中和度对离聚体的力学性能具有较大影响;Al离子含量高时,离聚体表现出溶胀行为. 相似文献
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聚(甲基丙烯酸甲酯/丙烯酸丁酯/丙烯酸钠)离聚体胶乳的合成及其… 总被引:1,自引:0,他引:1
以过硫酸钾为引发剂,十二烷基硫酸钠为乳化剂,合成了稳定的聚(甲基丙烯酸甲酯/丙烯酸丁酯/丙烯酸钠)离聚体乳液,并考察了引发剂用量、乳化剂用量、丙烯酸钠用量、反应温度、反应时间等因素对单体转化率、离聚体力学性能的影响。 相似文献
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将高乙烯基聚丁二烯橡胶(HVBR)与马来酸酐接枝改性后,与氢氧化钠络合制备了HVBR双羧酸型钠离聚体。结果表明,HVBR接枝共聚物断裂表面出现许多裂痕,在动态力学性能测试中发生断裂,而HVBR钠离聚体断裂表面出现许多相连的凸起结构。与HVBR相比,HVBR钠离聚体具有较好的抗湿滑性、低生热和低滚动阻力,拓宽了有效阻尼温域,更接近于室温。 相似文献
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丁苯橡胶(SBR)作为高不饱和度的橡胶被成功地用硫酸乙酸酐作为磺化剂在石油醚及丁酮混合溶剂配成的溶液中磺化,并用乙酸盐中和成离聚体。研究了离聚体及其他聚合物的共混物的熔融流动及力学性能。结果表明,SBR离聚体能很容易在硬脂酸锌存在下熔融加工,其行为象热塑性橡胶,硬脂酸锌能降低布拉本特(Brabender)混和机的扭矩所表示的熔融粘度,并增加流动活化能和离聚体的拉伸强度。离聚体的磺酸基含量能增加熔融粘度及拉伸强度。用于中和的阳离子的种类明显地影响离聚体的性能。离聚与聚丙烯或SBS的共混物在拉伸强度上表现出协同效应,而它与聚苯乙烯或顺-1,4聚丁二烯则呈现抵消效应。 相似文献
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无规离聚体的力学性能及其影响因素 总被引:1,自引:0,他引:1
本文对无规离聚体最基本的性能-力学性能,以及离子含量,平衡离子的性质、过量中和剂、增塑剂和制样过程对其本体力学性能的影响进行了系统的综述,反映了该领域的研究概况和较新的研究成果。 相似文献
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Polyurethane ionomers based on either poly(propylene glycol), PPG, or poly(ethylene glycol), PEO, and di- (4-isocyanatophenyl) methane, MDI, butane-1,4-diol and cis-2-butene-1,4-diol have been synthesized and characterized. Attempts to convert the unsaturated polyurethanes directly to ionomers by reaction with N-chlorosulphonyl isocyanate, CSI, followed by hydrolysis, failed due to the more favoured reaction of CSI with the labile hydrogen on the urethane linkage. Therefore, the cis-2-butene-1,4-diol was first converted to the dibenzoate which was then treated with CSI to form the β-lactam derivatives. Subsequent hydrolysis of these derivatives with tetra-n-butyl ammonium hydroxide solution produced ionic derivatives whilst at the same time regenerating the terminal -OH groups. These ionic diol intermediates were then used for synthesizing the polyurethane ionomers. 相似文献
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羧酸盐双子表面活性剂因其具有独特的物理化学性能及易生物降解等特性而广受国内外学者关注。本文主要对羧酸盐双子表面活性剂分子的疏水链、亲水基及联接基团的键合方式进行了概述。 相似文献
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In a continuing study of the preparation of ampholytic ionomers from the polymerization of ion-pair comonomers (cationic-anionic monomer pairs) with nonionic comonomers, the preparation of such ionomers from methyl methacrylate and n-butyl acrylate is described. For both systems, ionomers of varying ion contents were obtained. In the n-butyl acrylate system, a linear relationship of Tq vs. mol % ion content was found, but this did not occur for the methyl methacrylate ionomers. The solubilities of these materials in a wide variety of solvents is discussed. It appears that for n-butyl acrylate ionomers of high ion content in aqueous solution, a new form of polymeric surfactant is obtained. 相似文献
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Liquid-crystalline (LC) copolymers with redox-active groups were prepared by copolymerization of mesogenic and ferrocene-containing monomers (up to 10%). In these copolymers the ferrocene groups can be oxidized reversibly to prepare ionomers, while retaining the LC phase. It is thus possible to vary the amount of ionic groups in the ionomers by a redox reaction. The oxidized (charged) polymers show a strong excess X-ray scattering at small angles. This is typical for ionomers and is assigned to the scattering of ionic aggregates. Dynamic mechanical measurements show that these aggregates are effective as crosslinking points. Thus an oxidation-reduction reaction can be used to transfer an uncrosslinked polymer (reduced ferrocene groups, uncharged) reversibly into an oxidized polymer that acts like a weakly crosslinked gel. 相似文献
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用糠醇、乙酸酐和丙酸酐为原料,Fe2(SO4)3.xH2O为催化剂,NaHCO3为缚酸剂,合成了乙酸糠醇酯和丙酸糠醇酯。考察了反应物料比、反应时间、催化剂和缚酸剂用量对收率的影响。合成乙酸糠醇酯的最佳条件为:物料配比n糠醇∶n乙酸酐∶nFe2(SO4)3.xH2O∶nNaHCO3=2∶2∶0.03∶2(摩尔比),室温下反应4 h;合成丙酸糠醇酯的最佳反应条件为:物料配比n糠醇∶n丙酸酐∶nFe2(SO4)3.xH2O∶nNaHCO3=2∶2∶0.04∶2(摩尔比),室温下反应4 h。乙酸糠醇酯和丙酸糠醇酯的收率分别为88.8%和90.2%。该反应条件温和、产率高,可用于工业化大规模生产。目标产物结构经IR、1H NMR表征得以证实。 相似文献
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Tatsuya Sehata Takuto Yoshiura Tomonori Koda Hiroko Yano Motoaki Isokawa Akihiro Nishioka 《Polymer Engineering and Science》2023,63(2):331-337
The hot-tack properties of ethylene-methacrylic acid copolymers neutralized with sodium (Na) cations to produce ionomers were investigated. Specimens with neutralization degrees of 20%, 54%, and 70% were examined. After testing at low sealing temperatures (<130°C), the highest hot-tack strength was obtained from a specimen with a neutralization degree of 20%. In contrast, at high sealing temperatures (>140°C), the hot-tack strength increased with an increasing degree of neutralization. Observations of the surfaces of samples tested at low sealing temperatures after hot-tack tests showed that specimens having a neutralization degree of 20% exhibited cohesive breakdown while the 54% and 70% specimens underwent interfacial delamination. The effect of sealing temperature on hot-tack strength was determined by assessing the rheological properties of molten ionomers. The results suggested that, when testing at low sealing temperatures, a low melt viscosity provided high hot-tack strength by allowing flow diffusivity of the resin at the sealed interface. At high sealing temperatures, uniaxial elongational viscosity related to strain hardening contributed to the high hot-tack strength of these Na-based ionomers. The present study highlights the important effect of ionic aggregates on hot-tack properties. 相似文献