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温度对4-甲基丙烯酸2,2,6,6-四甲基哌啶醇酯与苯乙烯自由基共聚活性的影响 总被引:1,自引:0,他引:1
本文研究了4-甲基丙烯酸2,2,6,6-四甲基哌啶醇酯和苯乙烯在不同温度下的自由基共聚合反应。发现在石油醚、苯和二甲基甲酰胺等溶剂中,反应温度对共聚活性的影响不同。用NMR法测定了单体与溶剂的络合常数;计算了单体与溶剂相互作用的活化能和活化熵,依此对共聚活性与温度之间的关系进行了讨论。 相似文献
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本文研完了不同引发体系对带受阻胺基团的单体4-甲基丙烯酸2,2,6,6-四甲基哌啶醇酯(TMPM)自由基聚合的影响。分析比较了偶氮型引发剂和过氧化物引发聚合的结果,并讨论了以过氧化苯甲酰(BPO)引发TMPM聚合的阻聚机理。发现TMPM与BPO反应生成一个新的化合物——4-甲基丙烯酸-N-苯甲酰氧基2,2,6,6-四甲基哌啶醇酯。用IR、ESR、NMR及质谱等方法,对此化合物的结构进行了测定与表征。 相似文献
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<正> 带受阻胺基团的聚合物是一类新型光稳定剂,这类聚合物的合成研究已有一些报道,但是关于单体分子中的亚胺基对自由基聚合影响报道各不相同。 本文用偶氮二异丁腈(AIBN)为引发剂,对4-甲基丙烯酸-2,2,6,6-四甲基哌啶醇酯(MTMP)的均聚及其与苯乙烯(St)的共聚合进行了研究,同时也考察了MTMP的母体化合物4-羟基-2,2,6,6-四甲基哌啶(TMP)对St及甲基丙烯酸甲酯(MMA)聚合的影响,并对St-MTMP共聚合体系中介质的影响进行了初步探讨。 相似文献
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<正> 苯乙烯(简称St)-4(甲基丙烯酸)2,2,6,6-四甲基哌啶醇酯(简称MTMP)共聚物(简称PDS)是七十年代发展起来的一种新型高效光稳剂。本文用IR研究了一系列自由基聚合的PDS共聚物,找出了MTMP对序列结构敏感的吸收峰,发现MTMP的1152.5厘米~(-1)峰位置与三单元序列分布F_(SMS)值有一定线性关系,还对通过测量MTMP羰基伸缩振动ν_(C=O)峰位置来计算二单元序列分布P_(mm)的关系进行了讨论。 相似文献
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本文以苯为溶剂,在60±0.1℃下测定了MTMP(4-甲基丙烯酸-2,2,6,6-四甲基哌啶醇酯,M_1)与St(苯乙烯,M_2)、MVK(甲基乙烯酮,M_2)、VAc(醋酸乙烯酯,M_2)、AN(丙烯腈,M_2)的共聚物组成曲线与竞聚率(MTMP-St:r_1=0.30±0.05、r_2=0.63±0.05;MTMP-MVK:r_1=0.53±0.05、r_2=0.41±0.05;MTMP-VAc:r_1=14±0.5、r_2=0.02±0.01;MTMP-AN:r_1=13.7±0.5、r_2=0.20±0.05)。确定了MTMP的Q(0.56)和e(0.49)值。讨论了共聚物结构单元的序列分布。 相似文献
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本文从单体浓度、共聚单体配比、引发体系、温度等条件对带有易生成稳定自由基的4-甲基丙烯酸-2,2,6,6-四甲基哌啶醇酯与苯乙烯的自由基共聚合行为进行了探讨。发现在一般情况下符合自由基聚合规律。在不长的时间内可得到高产率(80%以上),较高分子量(~10~4)的白色粉末状共聚物。哌啶环上的亚胺基未表现出明显的阻聚作用。另外,用IR、NMR、VPO、元素分析等方法对共聚物的结构与性能进行了表征。此共聚物在多种普通有机溶剂中可溶,热稳定性能良好,毒性试验证明基本无毒。 相似文献
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用毛细管流变仪和显微摄影方法以及稳定自由基标记法研究了苯乙烯和4-(甲基丙烯酸)2,2,6,6-四甲基哌啶醇酯(简称PDS)共聚物共混聚丙烯的流变性能和形态分布,发现PDS相于聚丙烯相中的分布呈典型的分散球状颗粒,颗粒尺寸与流动条件有关,两相的分布状况与PDS分子量大小有关。同时也探讨了PDS共混比例对熔体流动性能的影响。添加少量PDS可改善聚丙烯熔体的流动性能。 相似文献
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The radical copolymerizations of 2,2,6, 6-tetramethyl 4-piperidinyl methacrylate (TMPM) with styrene in various solvents have been studied. The monomer reactivity ratios r_1 and r_2 were determined. It is observed that in all of these reaction systems, there are appreciable solvent effects on both r_1 and r_2, which can be correlated to the difference in chemical shifts of olefinic protons of TMPM. And the variance of the copolymer microstructure in various media was discussed. 相似文献
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The grafting of copolymer of styrene and 2, 2, 6, 6-tetramethyl-4-piperidinyl methacrylate onto polypropylene during heating was studied by IR and ESR. It is found that the graft reaction is going through the stable free radical > NO mechanism. 相似文献
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《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1537-1545
Radical solution polymerization of triallyl isocyanurate was conducted in methyl benzoate or hexyl benzoate as good or poor solvent, respectively, using AIBN as initiator at 60°C. An increased rate of polymerization, enlarged primary chain length, and promoted gelation were observed in the poor solvent. The actual gel point was compared with the theoretical one; the discrepancy between these points was great, although no substantial solvent effect was detected. These results are discussed in comparison with the results obtained from the polymerizations of its isomer triallyl cyanurate and diallyl terephthalate, a typical diallyl ester. The swelling ratio of the gel obtained just beyond the gel point was quite high, suggesting no microgelation up to the gel point conversion even in the solution polymerization. 相似文献
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Diblock copolymers containing polystyrene(PSt) and polybutyl methacrylate(PBMA) segments and random copolymer of styrene (St) and butyl methacrylate(BMA) have been prepared by atom transfer radical polymerization (ATRP).Diblock copolymers of BMA and St with predetermined molecular weight(1×10^4-6.5×10^4) and narrower molecular weight distribution(1.25-1.5) were obtained.The random copolymer compositions were determined by ^1HNMR spectroscopy and the reactivity ratios were evaluated by the extended Kelen-Tudos method to be YSt=0.91,YBMA=0.32. 相似文献