共查询到20条相似文献,搜索用时 83 毫秒
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2-烷基氨基-3-芳基-5-苄基-1-咪唑啉-4-酮的合成及杀菌活性 总被引:1,自引:0,他引:1
咪唑啉酮衍生物;反应;2-烷基氨基-3-芳基-5-苄基-1-咪唑啉-4-酮的合成及杀菌活性 相似文献
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以α-环柠檬醛(1)为A环合成子,以季盐(2)为C环合成子,经缩合及分子内环化反应得到关键中间体(5).为引入乙基,进行了Friedel-Crafts反应和脱氧反应等,共经7步反应得到了(±)-12-乙基-13-甲氧基-8,11,13-罗汉松三烯-7-酮[(±)-nimbonone](9)及(±)-12-乙基-13-甲氧基-8,11,13-罗汉松三烯(10). 相似文献
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采用微波和相转移催化法通过1-苯基-5-(4-苯基-1,2,4-三唑-5-巯基-3-甲硫基)四唑(2)与2-氯乙酰芳胺(3)反应高效、快速地合成了10种尚未见文献报道的1-苯基-5-[5-(芳胺羰基甲硫基)-4-苯基-1,2,4-三唑-3-甲硫基]四唑. 其结构经 IR, 1H NMR, 13C NMR 和元素分析表征. 生物活性实验结果表明, 该类化合物在较低浓度下部分化合物对小麦芽有很好的促进作用. 相似文献
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Grafting of acrylonitrile onto starch showed slightly higher yields when using soluble rather than insoluble starch, for reaction times < 1.5 hr. Beyond this time, the rate of grafting onto the soluble starch levels off, while that for grafting onto the insoluble starch proceeds leading to prograssive increase in the grafting yield. Momomer reactivity was in the following order: acrylonitrile > ethyl acrylate? methyl methacrylate. For the first two monomers, the order of reactivity is the reverse of that found for grafting onto cellulose; extremely low grafting yields resulted from grafting of ethyl acrylate rather than acrylonitrile onto starch. This result was attributed to the jelly nature of the polyethyl acrylate grafted starch, preventing diffusion of the monomer into the starch granules. This view was supported by the higher consumption of ceric ions at the start of the reaction, on grafting ethyl acrylate instead of acrylonitrile. As the reaction proceeds, the reverse takes place. Increase of ceric salt concentration, as well as the liquor to starch ratio, led to increased grafting yields. 相似文献
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乙酰丙酮铜(Ⅱ)引发淀粉与甲基丙烯酸甲酯接枝共聚合的研究 总被引:5,自引:1,他引:5
<正> 淀粉与丙烯酸酯类单体的接枝共聚物有可能作为生物降解塑料,而被应用于农业、医药及食品等各个方面。因此寻求价廉、高效的引发剂,以用于引发淀粉与烯类单体的接枝共聚,已引起了人们的极大兴趣。 过渡金属离子与β二酮的配合物,如乙酰丙酮铁(Ⅲ)、乙酰丙酮锰(Ⅲ)、乙酰丙酮铜(Ⅱ)等是一类引起注目的新型引发剂,已在羊毛、蚕丝、纤维素等天然大分 相似文献
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Enhancement of the grafting performance and of the water absorption of cassava starch graft copolymer by gamma radiation 总被引:1,自引:0,他引:1
Enhancement of the gamma radiation grafting of acrylonitrile onto gelatinized cassava starch was investigated. Infrared spectrometry was used to follow the chemical changes in the grafting reaction and from saponification. The saponified starch-g-PAN (HSPAN) was then characterized in terms of grafting parameters to provide a guide for the optimum total dose (kGy) and the appropriate ratio of starch/acrylonitrile for a fixed dose rate of 2.5 × 10−1 kGy/min. Other dose rates were also carried out to obtain the appropriate result of grafting copolymerization and of water absorption. A thin aluminium foil, covering the inner wall of the reaction vessel, was found to be far more effective than any other metal films in the enhancement of the grafting reaction and the water absorption as well. Nitric acid in the medium increases the grafting yield and the water absorption. Methyl ether hydroquinone inhibitor was evaluated for its ability to increase homopolymerization and decrease graft reaction. When styrene was used as a comonomer, it hampered the grafting of acrylonitrile onto starch backbone. The water absorption capacity was improved by freeze-drying the HSPAN. The treatment of the HSPAN with aluminium trichloride hexahydrate was found to enhance the degree of wicking, but to decrease the water absorbency. 相似文献
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Molecular weights and grafting frequencies of graft copolymers prepared with ferrous ammonium sulfate-hydrogen peroxide initiation showed a dependence on granule swelling similar to that found with ceric ammonium nitrate (increased swelling of starch granules decreased the number of grafted polyacrylonitrile chains and increased their average molecular weight). As with unswollen starch, the composition of the copolymer prepared from swollen starch was not influenced by granule size. Molecular weights of polyacrylonitrile branches grafted to swollen and unswollen starch were independent of reaction time; however, grafting frequencies with swollen and unswollen starch tended to converge toward a common value with increased reaction time and increased dilution. Data suggest that the influence of granule swelling on copolymer composition is due to a faster termination rate for growing polyacrylonitrile chains in unswollen starch. 相似文献
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Grafting of poly(methyl methacrylate) onto starch has been investigated in aqueous medium by using AIBN as radical initiator. Starch-g-PMMA has been characterized by determination of starch in the graft copolymer. Percentage of grafting has been determined as functions of concentration of monomer, concentration of initiator, reaction time, and temperature. From scanning electron microscopic studies, evidence for grafting of PMMA onto starch has been presented. 相似文献
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淀粉乙酸酯的阴离子接枝己内酯聚合研究 总被引:5,自引:0,他引:5
将淀粉在二甲基甲酰胺、吡啶存在下 ,以乙酸酐进行部分乙酰化 ,制备取代度为 0 7~ 1 9的淀粉乙酸酯 (St Ac) .以萘钠与淀粉乙酸酯中残余的羟基反应 ,将羟基转化为醇盐 (ONa) ,引发己内酯进行阴离子开环接枝聚合 ,合成了淀粉 聚己内酯接枝共聚物 (St g PCL) .采用凝胶渗透色谱法 (GPC)研究了接枝前后聚合物分子量的变化情况 ,并以接枝率、单体转化率对接枝反应进行了表征 .研究了接枝条件如温度、溶剂、引发剂和单体的用量对接枝率及单体转化率的影响 .研究发现随着反应温度升高 ,接枝率、单体转化率呈S曲线变化 ,单体浓度、引发剂浓度的增大有利于接枝反应的进行 . 相似文献
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Synthesis and Biodegradation of St-g-poly(MMA-co-VAc) Initiated by Manganic Pyrophosphate 总被引:1,自引:0,他引:1
ZHULin-hui CHENMi-feng JIYan XIAHai-ping DINGMa-tai 《高等学校化学研究》2004,20(2):232-235
Methyl methacrylate (MMA) and vinyl acetate (VAc) were grafted onto corn starch with manganic pyrophosphate { [Mn(H2P2O7)3]^3- } as the initiator and water as the reaction medium, The influences of reaction conditions, including pH value, initiator concentration, monomer concentration and its composition, on percent grafting and grafting efficiency were investigated. The graft copolymer was characterized by means of IR spectroscopy, scanning electron micrograph(SEM) and ^1H NMR spectroscopy. The biodegradation experiment showed that the degradation of corn starch-g-poly(MMA-co-VAc) was mainly from starch. However,after poly VAc in the side chain was transformed into poly vinyl alcohol(PVA), both starch and the grafted side chain could be degraded completely. 相似文献
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淀粉/DL-丙交酯接枝共聚物的合成和生物降解性能研究 总被引:23,自引:0,他引:23
以淀粉为接枝骨架 ,DL 丙交酯为接枝单体 ,在无水LiCl存在下 ,合成了淀粉 /DL 丙交酯接枝共聚物 .研究了接枝反应的投料比、反应时间、反应温度对单体转化率 (C % )、接枝率 (G % )和接枝效率 (GE % )的影响 .当DL 丙交酯与淀粉结构单元的摩尔比为 10∶1,反应温度为 80~ 85℃ ,反应时间为 4h ,C % ,G %和GE %可分别达到 37 3 %、179 7%和 6 8 0 % .用差示扫描量热 (DSC)分析仪、红外光谱仪和X 射线衍射仪对合成的接枝共聚物进行了表征 ,结果表明 ,淀粉和DL 丙交酯反应生成了淀粉 /DL 丙交酯接枝共聚物 .防水实验结果表明 ,该产物在给定条件下可使纸板的吸水率由 41 1%降低到 1 0 % .降解实验表明该接枝共聚物能够被酸、碱及微生物完全降解 相似文献