凝胶聚苯乙烯白球氯甲基化对树脂的影响

氯甲基化是合成苯乙烯型阴离子交换树脂过程中很重要的一步反应,以聚苯乙烯白球、氯甲醚为原料,以氯化锌/氯化铁为催化剂,通过氯甲基化反应可得中间产品氯甲基化聚苯乙烯。在这些氯甲基团上接上季胺基团,就可以得到强碱型苯乙烯型阴离子交换树脂。     

聚苯乙烯硫代氨基脲螯合树脂的制备及其对重金属离子的吸附性能研究

以苯乙烯为单体采用分散聚合法合成聚苯乙烯微球,1,4-二氯甲氧基丁烷与聚苯乙烯反应得到氯甲基化聚苯乙烯,用氯甲基化聚苯乙烯与硫代氨基脲反应得到的聚苯乙烯硫代氨基脲螯合树脂。采用红外光谱法、扫描电镜、X射线光电子能谱对其结构及元素组成进行分析。考察了聚苯乙烯硫代氨基脲螯合树脂对Ag+、Cu2+、Pb2+和Cr3+重金属离子的吸附性能。聚苯乙烯硫代氨基脲螯合树脂对Ag+、Cu2+、Pb2+和Cr3+的吸附容量分别为16.38 mg/g、15.25 mg/g、13.69 mg/g和13.12 mg/g。     

废旧PS泡沫微波法制备对硝基苯甲酸工艺

用废旧聚苯乙烯泡沫为原料,通过微波反应器制备对硝基苯甲酸,探讨了影响对硝基苯甲酸产率的因素,如硝酸的质量浓度和用量、反应压力和时间、微波反应器功率、催化剂用量等.结果表明,在反应压力2.0 MPa、反应温度200℃、反应时间 60 min、硝酸的质量浓度68 g/mL、微波反应器功率1 200 W、硝酸与对硝基聚苯乙烯的质量比5.0:1.0、催化剂用量为对硝基聚苯乙烯质量的0.1%的最优条件下.对硝基苯甲酸的产率可达85%,产品纯度为99.4%.     

氯甲基化聚苯乙烯-二乙烯苯共聚体中氯含量的测定

本文采用氧瓶--汞量法测定氯甲基化聚苯乙烯-二乙烯苯共聚体中氯的含量.详细考察了样品(苯乙烯-二乙烯苯共聚物)燃烧、气体吸收、样品滴定条件的影响.本法简便、快速,不需特殊仪器.     

大孔型交联聚苯乙烯三已基苄基季铵盐相转移催化剂的研制

本实验采用大孔型氯甲基化交联聚苯乙烯为骨架经氯甲基化，季胺合成大孔型交联聚苯乙烯三已基苄基氯化铵相转移催化荆。并测定了其交换容量。每克干树脂的全支换容量达44毫克以上。并将此合成的催化剂应用于环乙醇的氧化，制备环已酮，效果良好。     

Blanc氯甲基化聚苯乙烯树脂的制备及条件筛选

以聚苯乙烯类树脂为原料,采用Blanc氯甲基化的方法对交联聚苯乙烯类树脂进行氯甲基化,并对氯含量进行了测定筛选出产率高的树脂,对氯甲基化方法进行筛选。     

氯甲基化交联聚苯乙烯含氯量分析

本文用裂解气相色谱研究氯甲基化交联聚苯乙烯的热裂解行为。实验发现,裂解产物对—甲基苯乙烯的峰高百分数与含氯量呈线性关系,可用以表征该共聚物的含氯量。文章还探讨了该共聚物的裂解机理。     

何首乌中二苯乙烯苷类物质的超声波提取工艺优化

采用超声波辅助乙醇提取何首乌中二苯乙烯苷类物质,考察了乙醇浓度、料液比、提取温度、提取时间和提取功率对提取率的影响。结果表明,提取最佳工艺条件为:乙醇浓度60%,料液比1∶25 g/m L,提取温度65℃,提取时间1.5 h和提取功率800 W。在此条件下,二苯乙烯苷类物质的提取率达7.19%。     

何首乌中二苯乙烯苷类物质的超声波提取工艺优化

采用超声波辅助乙醇提取何首乌中二苯乙烯苷类物质,考察了乙醇浓度、料液比、提取温度、提取时间和提取功率对提取率的影响。结果表明,提取最佳工艺条件为:乙醇浓度60%,料液比1∶25 g/m L,提取温度65℃,提取时间1.5 h和提取功率800 W。在此条件下,二苯乙烯苷类物质的提取率达7.19%。     

微波辐射制备Fe3O4-聚苯乙烯复合磁性微球

采用微波辐射法制备了Fe3O4-聚苯乙烯复合磁性微球。通过Fe3O4磁流体的制备及改性,利用微波辐射使苯乙烯自聚反应能够在Fe3O4磁性颗粒表面顺利进行,最终得到复合磁性微球。实验考察了微波功率大小、聚合反应体系pH值、磁流体用量等反应条件的影响,通过红外谱图、热重谱图分析了产物的结构和热稳定性,利用沉降实验定性地表征了产物的磁响应性。结果表明：微波功率为130w时能迅速成功地制备出磁含量为24．47％的复合磁性微球。     

Non-cross-linked polystyrene-supported piperazine: synthesis and use in Knoevenagel condensation under microwave-assistance

Copolymerization of styrene and functionalized monomer [tert-butyl-4 (p-vinylbenzyl) piperazine-carboxylate] and deprotection of Boc group readily afforded soluble non-cross-linked polystyrene (NCPS)-supported piperazine in 58% yield and high loading (3.0 mmol NH/g) under microwave. The copolymers were easily characterized by routine analytical methods such as IR, ¹H NMR and elemental analysis and smoothly catalyzed Knoevenagel condensation of aldehydes with malonitrile or ethyl cyanoacetate under microwave irradiation in CHCl₃ for 20 min to afford the desired alkenes in good purity and yield.     

Microwave-assisted epoxidation of styrene with molecular O2 over sulfated Co–Y–ZrO2 solid catalyst

The microwave-assisted styrene epoxidation reaction with molecular O₂ as an oxidant was studied over a sulfated Co–Y-doped ZrO₂ solid catalyst. The microwave irradiation (400 W) resulted in similar styrene conversion and styrene oxide selectivity, in reduced time, as compared to conventional thermal heating. Higher power (800 W) of microwave irradiation decreased the styrene oxide selectivity as well as leading to the formation of styrene glycol. DMF was found to be the most suitable solvent for epoxidation of styrene with molecular O₂ under microwave irradiation and yielded maximum oxide selectivity (91%) at 120 °C. The microwave-assisted oxidation reaction resulted in time saving and is energy conserving method.     

Optimized benzaldehyde production over a new Co-ZSM-11 catalyst: Reaction parameters effects and kinetics

An efficient Co-ZSM-11 catalyst has been synthesized for benzaldehyde production by the selective styrene oxidation. Reaction parameters such as catalyst mass, reaction temperature, molar ratio styrene/hydrogen peroxide and stirring speed were optimized, by performing the styrene oxidation reaction in a stirred batch system with fine particles of Co-ZSM-11 in suspension under microwave heating. A kinetic study was done by using the initial rate method and the Arrhenius parameters were estimated. This catalyst presents a higher reaction rate about 30% with respect of those found in literature and a higher selectivity towards benzaldehyde about 80% at optimal conditions.     

乳液法聚苯乙烯纳米微球的制备

采用十二烷基硫酸钠为乳化剂、过硫酸盐为引发剂、苯乙烯为单体,在低水油比的条件下,采用乳液聚合方法合成了聚苯乙烯纳米微球,探讨了乳化剂用量、乳化时间、反应温度、引发剂用量和反应时间对单体转化率及产物分子量的影响.结果表明:在低水油比条件下,反应参数对苯乙烯的转化率和聚苯乙烯的分子量具有一定的影响.在最优条件下苯乙烯的转化率达到98%、聚苯乙烯的分子量达到32万.激光粒度分布测试结果显示,所得产物为单分散纳米微球.     

On factors determining the swelling ability of crosslinked polymers

Macronet isoporous styrene polymers were obtained by a cross-linking process (using monochlorodimethyl ether as the cross-linking agent) applied to both dissolved linear polystyrene and swollen styrene copolymers with 0.3–1.0% divinylbenzene at the same polymer-solvent weight ratio for all the systems. The lower equilibrium swelling capacity of copolymer-based three-dimensional structures as compared to that of linear polystyrene cross-linked to an equal extent is explained by the presence in the initial swollen styrenedivinylbenzene copolymers of internal strains inhibiting an increase in the volume of the final polymer network. Cross-linking of the linear polystyrene by means of a partially chloromethylated polystyrene shows that irregularity in the distribution of cross-linking bridges enhances the equilibrium swelling capacity of the final gels.     

低分子量聚苯乙烯悬浮聚合工艺

以过氧化二苯甲酰为引发剂,聚乙烯醇为悬浮分散剂,叔十二烷基硫醇为链转移剂,通过悬浮聚合的方法制得了具有可控分子量的白色颗粒状聚苯乙烯。考察了引发剂、分散剂、链转移剂的添加量、反应温度、反应时间、搅拌速度、水和单体比例等对聚合产物分子量和收率的影响。研究表明本合成最适宜的反应条件为:反应温度75~80℃,反应时间7小时,V水/V单体=8,m引发剂/m单体=10%,m分散剂/m单体=3.5%,m硫醇/m单体=3%时,得到的产物分子量1.2万左右。     

微波辅助艾叶多糖的热水浸提工艺研究

采用微波辅助热水浸提法研究了艾叶多糖的提取工艺,选用单因素实验法,探索料液比、浸提温度、浸提时间和微波功率对艾叶多糖提取率的影响.实验结果表明,最佳浸提工艺为:料液比1:20(g·mL-1)、浸提温度85℃、浸提时间20min、微波功率400W.稳定性实验结果表明,该工艺条件稳定、成熟度较高,在优化条件下艾叶多糖提取率...     

Studies on polymer blends. II. Butadiene–styrene copolymers and polybutadiene–polystyrene blends

The properties of butadiene–styrene copolymers and of polybutadiene–polystyrene blends were compared. Polybutadiene, polystyrene, and four copolymers having styrene contents of 20, 40, 60, and 80% were prepared. The copolymers were compared with blends having various styrene contents and prepared by means of latex blending and roll blending. Vulcanizates were prepared by three different curing methods, i.e., sulfur cure, peroxide cure, and radiation cure. The results of the benzene extraction of three vulcanizates showed that the polystyrene blended was not cured by any of the curing methods used. The properties of the vulcanizates of the copolymers were markedly different from those of the blends, i.e., in the case of the blends the properties showed a linear relationship with their blending ratio, while in the copolymers the properties showed a curvilinear relationship which had an inflection point at a styrene content of about 60%. From this phenomenon of the copolymers, it was proposed that the second-order transition point of styrene is the cause of the properties showing this peculiar point. From the results, it was found that the behavior of styrene in copolymers is essentially different from that in blends.     

微波-超声波协同萃取银杏黄酮的工艺研究

以银杏叶为材料,研究了乙醇浓度、微波功率、微波处理时间、料液比、银杏叶粉碎颗粒大小以及微波-超声波协同作用对银杏黄酮提取效率的影响。结果表明微波处理,微波-超声波协同处理可以显著提高银杏黄酮的提取率。确定了最佳的微波处理条件:70%乙醇为萃取液,料液比1∶20,粉末颗粒80目,微波功率50W,微波处理时间4 m in,处理后水浴回流提取2 h所得提取液的黄酮提取率达到81.76%,比直接水浴提取提高了1.3倍,微波-超声波协同处理的黄酮提取率达到83.54%。