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VAc/MA/AA三元无皂乳液共聚的研究 总被引:4,自引:1,他引:4
以过硫酸钾(KPS)为引发剂,对VAc/MA/AA三元无皂乳液共聚进行了研究。探讨了引发剂用量、功能单体用量(AA)对乳液稳定性、胶乳粒子粒径、粒径分布及胶乳粘度、粘接强度等性质的影响。结果表明: 引发剂用量小于单体总质量的0.7%时,随着KPS用量的增加,胶乳粒子粒径减小,粒径分布变窄;引发剂用量大于单体总质量的0.7%时,随着KPS用量的增加,胶乳粒径及分布都增大,KPS用量为单体总质量的6%时,单分散性好;共聚乳液的粒径随AA用量的增加而增加,粒径分布则随AA用量的增加而减小,乳液粘度随AA用量增大而降低,而粘接强度随AA用量增大而增加,耐水性下降。 相似文献
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丙烯酸乳液胶粘剂的研究 总被引:3,自引:2,他引:3
采用半连续乳液聚合工艺,以MMA、BA、AA等为主要单体,加入乳化剂、引发剂、交联剂,经共聚反应,合成自交联型丙烯酸酯乳液胶粘剂。讨论了聚合机理,考查了固含量、离子稳定性、离心稳定性、剥离强度、拉伸强度、粒径、黏度等多项性能;根据综合的性能测试,分析了单体种类及配比、共聚物的玻璃化温度、丙烯酸用量、乳化剂用量及配比、引发剂用量、温度等因素对乳液型胶粘剂性能的影响,得出了最适宜的反应条件和胶粘剂最佳配方。通过性能对比,表明自交联型丙烯酸酯乳液胶黏剂性能更为优异。 相似文献
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以过疏酸钾(KPS)为引发剂,醋酸乙烯(VAC)为主单体,采用乳液共聚方法,通过改变聚合温度、保温时间、引发剂用量及复合乳化剂配比和用量,合成改性聚醋酸乙烯上浆料,并研究了该乳胶液的流变特性和在不同条件下的稳定性。 相似文献
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以丙烯酸丁酯(BA)为软单体,甲基丙烯酸甲酯(MMA)为硬单体,丙烯酸(AA)为功能单体,采用预乳化半连续种子乳液聚合的方法制备了丙烯酸酯乳液复膜胶,研究了软硬单体配比、乳化剂种类及用量、引发剂用量以及功能单体用量对乳液性能的影响。结果表明,在单体质量比BA∶MMA∶AA为80∶19∶1,引发剂用量占单体质量的0.7%,乳化剂SDS与OP-10的质量比为1∶2.5,乳化剂用量占单体质量3.5%的条件下,聚合过程稳定、产率高,制备的乳液粒子较细、黏度低、稳定性好,纸塑剥离强度可达40.4 k N/m。 相似文献
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《Ceramics International》2019,45(15):18551-18555
Melting temperature has great influence on the high temperature properties and working temperature limits of ultra-high temperature ceramics (UHTCs) In order to bypass the challenge in the measurement of ultra-high melting points, this paper proposed a novel method to predict UHTCs melting temperature via machine learning. A dataset including more than ten thousand melting temperature data has been established, which covers 8 elements and most of the known non-oxide UHTCs. We built up an element to ceramic system framework by back propagation artificial neural network (BPANN) with the accuracy approaching to 90% and the correlation coefficients approaching to 0.95. Our work provides a probability to get the high accuracy melting temperature of UHTCs, and a more convenient way to develop novel materials with higher working temperature. The given case of melting temperature prediction of Hf-C-N ceramics proves the generality of the artificial neural network (ANN). An inter-validation of melting temperature prediction using our network with materials thermodynamics and density functional theory (DFT) has been demonstrated, indicating that our network is of powerful prediction ability. 相似文献
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室温固化耐高温胶粘剂的研究 总被引:2,自引:2,他引:0
以环氧氯丙烷和对氨基苯酚为主要原料制备了多官能度的环氧树脂(EP-005),并采用自制的复配固化剂、纳米SiO2、特殊的增韧剂和特种填料等进行改性,制得了一种结构加固用的建筑耐温结构胶。实验结果表明,该胶粘剂可常温固化,加固后的构件可在常温与高温(150℃)环境中长期使用;该胶粘剂在150℃时的剪切强度为17.28 MPa,常温拉伸强度为42.60 MPa,常温压缩强度为90.63 MPa;该胶粘剂具有卓越的综合性能,并已成功用于建筑工程等领域中。 相似文献
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我公司生产能力为合成氨 8万 t/a、尿素 1 0万 t/a,近年来随着能力的增加 ,变换系统能力明显不足。 2 0 0 0年 8月 ,中、低变炉新添加了部分催化剂 ,并一直运行到 2 0 0 2年 4月 ,在此期间 ,变换系统极不稳定 ,阻力上升 ,蒸汽消耗增加 ,CO跑高。基于以上情况 ,我公司决定对低变炉催化剂重新进行硫化。下面 ,笔者将对本次硫化工作及处理后的效果作一总结。1 变换催化剂的基本情况中变催化剂 B1 1 7,棕褐色圆柱片剂 ,堆密度1 .5~ 1 .6kg/L ,其主要成分 Fe2 O365 %~ 75 %、Cr2 O33%~ 6%。低变催化剂 B30 1 Q,浅兰色球形颗粒 ,粒度 3~ … 相似文献
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New components, spacers and membranes, have been developed for electrodialysis at temperatures up to 80°C. The performance of a sea water plant using these components is examined. Total water costs depend on membrane cost and membrane life. Even with conservative assumptions with regard to membrane cost and life, it appears possible to desalt sea water for less than 28ø per cubic meter (< $1.05/1000 gallons). The current status of the development and testing program is described. 相似文献
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油品密度在油品检验过程中是一项基本而重要的指标,在测量过程中常受多种条件的影响。本文在对催化原料密度测量时从测量温度和被测原料在恒温浴中恒温时间等方面对其的影响结果进行了充分的探讨,从而对影响液体石油产品密度测定的因素进行了分析。 相似文献
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《Ceramics International》2023,49(8):11865-11874
3Y-TZP ceramics are prepared by solid state method and surface carburization process, and the effect of surface carburization on its the low temperature degradation is studied. The conventional sintered samples completely lost its mechanical properties after aging for 15 h, while the failure time of the surface carburized samples are 300 h. In addition, the nuclear growth rate of the surface carburized samples (αd) and the nucleation rate (Nr) is lower than that of sintered samples, αd plays a dominant role in the degradation process at low temperature and is the key factor determining the aging rate. At the same time, it is found that carbon is dissolved in zirconia lattice in the form of electrically neutral atoms, which will not destroy the original charge balance and produce new oxygen vacancies when entering the interstitial site. More importantly, the precipitation rate of Y3+ from zirconia lattice is the key factor to determine the low-temperature phase transition of tetragonal-monoclinic(T-M). The treatment method of surface carburization has significantly improved the low-temperature degradation performance of 3Y-TZP ceramics, which provides a basis for the application of zirconia ceramics in low-temperature and humid environment. 相似文献