首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 171 毫秒
1.
丙烯酸改性松香(2-甲基丙烯酰氧基乙基)酯的合成和表征   总被引:3,自引:1,他引:2  
以丙烯酸改性松香(AR)为原料,先与草酰氯反应合成丙烯酸改性松香酰氯(AR-C l),然后与甲基丙烯酸-2-羟基乙基酯进行酯化反应合成了丙烯酸改性松香(2-甲基丙烯酰氧基乙基)酯(AR-2-HEMA),并分别采用FT-IR、GC-MS、13C NMR和差示扫描量热仪(DSC)对其结构和性能进行表征。研究结果表明,丙烯酸改性松香(2-甲基丙烯酰氧基乙基)酯主要由丙烯海松酸(2-甲基丙烯酰氧基乙基)酯(37.88%)和树脂酸(2-甲基丙烯酰氧基乙基)酯(52.48%)组成。丙烯海松酸(2-甲基丙烯酰氧基乙基)酯两种异构体质量分数分别为31.79%和6.09%。所制备的丙烯酸改性松香(2-甲基丙烯酰氧基乙基)酯在引发剂的存在下可以发生聚合反应。  相似文献   

2.
中空介孔二氧化硅微球的制备及表征分析   总被引:1,自引:0,他引:1  
以二氯化-N,N'-二(3-氢化松香酰氧-2-羟丙基)四甲基乙二胺(DHRT)为模板剂,正硅酸乙酯为硅源,采用溶胶-凝胶和水热合成的方法,分别制备了中空介孔二氧化硅微球SiO2-1和SiO2-2.利用SEM、TEM、FT-IR、XRD和氮气吸附-脱附对SiO2-1和SiO2-2进行表征分析,结果表明:两种方法均已成功制...  相似文献   

3.
研究了硝酸氧化松香的反应,以探讨硝酸用量和反应时间对氧化反应的影响。采用红外光谱、紫外光谱、液质联用对松香氧化产物的结构进行了测定。实验结果表明:以硝酸为氧化剂,乙酸乙酯为溶剂,在反应温度为75℃,反应时间为8h,n硝酸:n松香=22:1时,氧化产物酸值达到318mgKOH/g。松香中的主要成分已发生了氧化,共轭双键断裂生成了多羧基氧化产物,初步推断出可能的3个主要氧化产物的结构分别为:3.异丙基-6.(1,3-二甲基-2,3-二羧基环己基)苯甲酸,6-(1,3-二甲基-2,3-二羧基环己基).1,3-苯二甲酸,12.硝基-7,11,14-三羰基-△8(9)-枞酸。  相似文献   

4.
制备、表征了酸功能化离子液体1-(3-磺酸)丙基-3-甲基咪唑对甲苯磺酸盐((HS03-pmim)pTSA),并用于催化合成松香甲酯的反应研究,详细考察了甲醇用量、催化剂用量、反应温度、反应时间等因素对反应结果的影响,得到较佳的工艺条件:甲醇15g,离子液体2.5g,松香5g,反应温度200℃,反应时间4h。在该条件下,所得产物松香甲酯的酸值为17.4mg/g;并对离子液体(HSO3-pmim)pTSA的重复使用性能进行了考察,分出的离子液体在不经处理直接重复使用5次时,所得产物松香甲酯的酸值为20.1mg/g,具有较好的可重复使用性。  相似文献   

5.
松香基尾巴新型双子表面活性剂的焓熵补偿   总被引:1,自引:1,他引:0  
为研究双子(Gemini)表面活性剂结构中疏水"尾巴"对其在水溶液中行为的影响,对以脱氢松香酰基为疏水链"尾巴"的季铵盐双子表面活性剂二氯化-N,N′-二(3-脱氢松香酰氧-2-羟丙基)四甲基乙二胺的胶团化行为进行了研究,发现焓变(ΔH)和熵变(ΔS)呈线性关系,表明其胶团化过程存在焓熵补偿现象,补偿温度为310.8 K左右,为熵驱动过程。  相似文献   

6.
松香酰谷氨酸的合成及表面活性   总被引:12,自引:1,他引:12  
松香酸与三氯化磷反应制得松香酰氯,收率85%以上。松香酰氯与谷氨酸钠进行缩合反应合成了松香酰谷氨酸,通过正交试验优化的合成条件为:松香酰氯与谷氨酸摩经为1:0.8,反应温度25-30℃,PH7-8,反应时间2.5h,以丙酮与水体积比1:1为混合溶剂,收率84%,并对松香酰谷氨酸双钠的表面活性进行了测定。  相似文献   

7.
以脱氢枞酸为原料,经酰氯化反应后与己二醇反应合成脱氢枞酸羟己酯,然后再用甲基丙烯酰氯进行酯化反应,合成基于脱氢枞酸的柔性单体——脱氢枞酸(2-甲基丙烯酰氧基己基)酯,得率41%。并分别采用了FT-IR、1H NMR、13C NMR、DSC和GPC对其结构和性能进行表征。研究结果表明,脱氢枞酸(2-甲基丙烯酰氧基己基)酯在引发剂的存在下可以发生聚合反应,均聚物相对分子质量为20 000~30 000,玻璃化转变温度约为-21.82℃。  相似文献   

8.
羟基保护法合成松香酰二乙醇胺及其表面活性初探   总被引:1,自引:0,他引:1  
先用二氢吡喃保护二乙醇胺的羟基,与松香酸甲酯(RAME)反应制得松香酰二乙醇胺二(四氢吡喃醚)后,再经羟基解保护后制备松香酰二乙醇胺(RDEA)。二次回归正交试验优化的合成条件为:松香酸甲酯与二乙醇胺二(四氢吡喃醚)摩尔比1:1.6,反应温度93℃,反应时间4.4h,催化剂乙醇钠用量为二乙醇胺二(四氢吡喃醚)的2.5%,松香酰二乙醇胺得率为93.87%。性能测定表明,松香酰二乙醇胺的发泡能力及泡沫稳定性、乳化能力与十二烷基硫酸钠(K12)相当,临界胶束浓度较K12略大。松香甲酯化制备松香酸甲酯的最佳制备条件:松香与甲醇摩尔比1:3、反应时间1h、反应温度70℃、催化剂氢氧化钾用量为松香的2%,酯化率为95.50%。  相似文献   

9.
以四甲基乙二胺及三乙烯二胺为连接基制备了两种松香基季铵盐Gemini表面活性剂Ⅰ与Ⅱ,经表面活性分析:Ⅰ与Ⅱ的CMC值分别为1.42×10-4、9.7×10-4 mol/L,γCMC为36.69、43.41 mN/m;乳化时间为16、10 min;降低表面张力的效率(pc20)计算值为4.2、3.2;HLB计算值皆约为14.45;Ⅰ与阴离子相溶性好,Ⅱ与阴离子相溶性较差.由实验分析结果探讨了连接基性质对松香基季铵盐Gemini表面活性剂的影响,结果表明:以柔性链为连接基的松香基季铵盐Gemini表面活性剂Ⅰ的活性优于以刚性链为连接基的松香基季铵盐Gemini表面活性剂Ⅱ.  相似文献   

10.
以16-甲基-2,6,6,8-四甲基三环-8-烯酮肟(甲基柏木酮肟)和卤代物为原料,通过烷基化反应合成了6个甲基柏木酮O-取代肟类化合物:16-甲基-2,6,6,8-四甲基三环-8-烯酮O-苄基肟(2a)、16-甲基-2,6,6,8-四甲基三环-8-烯酮O-(4-氯苄基)肟(2b)、16-甲基-2,6,6,8-四甲基三环-8-烯酮O-(4-氰基苄基)肟(2c)、16-甲基-2,6,6,8-四甲基三环-8-烯酮O-(2,6-二氯苄基)肟(2d)、16-甲基-2,6,6,8-四甲基三环-8-烯酮O-(4-叔丁基苄基)肟(2e)和16-甲基-2,6,6,8-四甲基三环-8-烯酮O-(邻氟苄基)肟(2f)。采用FT-IR、GC-MS、~1H NMR以及~(13)C NMR等手段对产物进行结构表征,确认了产物结构。以苄基氯为例探讨了溶剂种类、催化剂四丁基溴化铵用量、苄基氯用量、反应温度以及反应时间对反应转化率和得率的影响,得到最佳的工艺条件为:以甲苯为溶剂,n(甲基柏木酮肟)∶n(四丁基溴化铵)∶n(苄基氯)=1.0∶0.12∶1.4,温度为70℃,反应时间24 h。在此条件下,产物2a的得率为78.10%,2b~2f的得率在58.91%~71.36%之间。  相似文献   

11.
研究了以没食子酰基为功能性基团、纤维素为分子骨架的功能高分子材料的合成。将没食子酸先用醋酐进行乙酰化保护酚羟基,后与酰氯化剂SOCl2或PCl5反应,制得三乙酰基没食子酰氯,得率分别为80%和90%;再以吡啶为催化剂与纤维素进行酯化反应制得三乙酰基没食子酰纤维素;然后脱去乙酰基制得功能高分子化合物没食子酰纤维素,酯化率为43.6%。功能特性试验表明,该产物具有吸附结合明胶和络合Fe3+能力,在稀酸、醇和热水中稳定并可再生。1g干产物可结合明胶65.5mg,解吸率约98%;可络合Fe3+76.5mg,解吸率约98%。本研究为进一步研制可用于酿造过程的能结合蛋白质和络合金属离子的新型功能高分子材料奠定了技术基础。  相似文献   

12.
以小麦秸秆为原料,浓硫酸为催化剂,乙醇为溶剂进行液化实验,分析了液化产物的组成,考察了不同条件对目标产物乙酰丙酸乙酯(EL)得率及液化率的影响。结果表明:在浓硫酸用量10%、反应温度190℃、反应时间60 min,液固比为18∶1(g∶g)条件下,小麦秸秆的液化效果较好,液化率为75%,此时EL的得率为18.11%;经红外光谱分析可知秸秆在反应过程中发生降解;液体产物中包含醛、酮、酯、酚、酸类等多种含氧化合物,纤维素降解生成葡萄糖、葡萄糖苷、乙氧基甲基糠醛等中间产物,并最终转化为乙酰丙酸乙酯。  相似文献   

13.
To elucidate the formation and chemical structures of water-soluble material in acid-soluble lignin (ASL), lignin aromatic nuclei model compounds of creosol (I) and 5-methoxycreosol (II) were reacted with xylose or xylan in the presence of apocynol as a counterpart for condensation in 72% sulfuric acid (SA). The reaction of I gave mainly condensation product. However, the condensation reaction of II with apocynol was suppressed because of steric hindrance from the methoxyl group, and II yielded a C-xyloside after refluxing in 3% SA together with condensation products. To obtain information on CHCl3-soluble material in ASL, model compounds of arylglycerol--aryl ethers with guaiacyl (VIII) and syringyl (X) nuclei were treated by the Klason procedure. VIII gave only insoluble polymerized product, while X gave insoluble polymerized product and CHCl3-soluble low molecular weight products, which were dissolved in 3% SA. These results prove earlier views that water-soluble material in ASL consists of condensation products formed from syringyl lignin and monosaccharide units in hemicellulose. In addition, the CHCl3-soluble material in ASL appears to be composed of low molecular weight degradation products from SA treatment of Klason lignin with the syringyl nucleus.Part of this report was presented at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001 and at the 47th Lignin Symposium, Fukuoka, October 2002, and was reviewed in Mokuzai Gakkaishi (2002) 48:55–62  相似文献   

14.
指出了对氨基苯甲磺酰吡咯烷是合成阿莫曲坦药物的关键中间体,以氯苄为原料,经硝化、磺化、氯化、氨解、硝基还原等多步反应得到目标产物,并对各步反应的工艺进行了探索。  相似文献   

15.
This paper summarises the results from 35 years-observed thinning experiments on 256 permanent sample plots in 10–60 year-old stands of ash, aspen, birch, oak, pine and spruce in Lithuania. Thinning enhanced crown projection area increment of residual trees. The largest effect was observed in stands of aspen and birch (growth increase by 200%), followed by ash and oak (over 100%), and spruce and pine (about 80%). Thinning also promoted dbh increment, especially in younger stands, and the increase of dbh increment was positively correlated with the thinning intensity. The strongest reaction was exhibited by oak and aspen, while ash, birch and conifers reacted to a lower extent. Low and moderate intensities of thinning stimulated volume production in younger stands while the opposite was observed in older stands with increasing removals. Spruce stands exhibited relatively strongest increase of volume increment and pine, –the weakest, while the effect on deciduous species was intermediate. The results demonstrate that significant increase in volume increment is achievable with thinning of only young forest stands, e.g. 10–20 year-old pine, birch and ash, or 10–30 year-old oak, aspen and spruce.  相似文献   

16.
Summary Properties of wood can be improved by reacting chemicals with hydroxyl groups of wood cell wall polymers. To achieve this improvement in wood properties, bioactive compounds containing hydroxyl groups, such as pentachlorophenol, 3,5-dimethyl phenol, and 2-naphthol, can be reacted with epichlorohydrin to give corresponding glycidyl ethers. The new epoxide formed during this reaction can be used to bond bioactive compounds to wood. This bonding may result in improved wood properties. The objective of this study was to develop a simple procedure for synthesizing glycidyl ethers. The alcohol was reacted with epichlorohydrin and a catalyst and monitored by thin-layer chromatography. Shortwave ultraviolet light was used to detect spots. Resulting products were analyzed for carbon, hydrogen, and in one case, chlorine. Reaction of pentachlorophenol with epichlorohydrin formed only one enantiomeric glycidyl ether, whereas reaction of 3,5-dimethyl phenol with epichlorohydrin led to two enantiomeric glycidyl ethers in a 1 to 3 ratio. Reaction of 2-naphthol with epichlorohydrin also led to two enantoimeric glycidyl ethers in equal amounts. In future research, these glycidyl ethers will be reacted with wood, and their toxicity to wood-destroying fungi in bonded form will be determined.  相似文献   

17.
测定了茶叶儿茶素及绿茶、红茶中的儿茶素与盐酸(硫酸)-香草醛的显色反应水平,通过对反应系数、准确度、精密度测定和比较,评价了儿茶素与酸性香草醛的显色反应能力。结果表明:两种酸性体系对儿茶素反应灵敏,且呈高度线性相关(R2盐酸=0.997 6±0.001 4,R2硫酸=0.997 8±0.001 8);显色反应系数上,盐酸法为34.77±10.00(绿茶)、83.83±20.13(红茶);硫酸法为39.65±8.97(绿茶)、86.68±19.87(红茶),均低于茶叶儿茶素总量经验计算公式中Roberts系数(145.68)。盐酸-香草醛显色反应体系的回收率为94.22%±3.33%(绿茶)、99.71%±1.39%(红茶),精密度的变异系数为0.08%(绿茶)、0.07%(红茶);硫酸-香草醛显色反应体系的回收率为95.78%±1.95%(绿茶)、99.95%±2.56%(红茶),精密度的变异系数为0.07%(绿茶)、0.06%(红茶),表明两种体系均能测定茶叶儿茶素总量。来源于不同茶类、等级茶的儿茶素类与酸性香草醛的显色能力差异极显著(F=37.434>F0.01[1,5]=6.61),说明两种反应体系均能客观表征茶叶儿茶素总量。由经验公式计算法得到的回收率(绿茶120.59%±34.86%,红茶114.09%±0.20%)和变异系数(绿茶28.91%,红茶0.17%)均不稳定,且其测定的儿茶素总量也偏高于实际值。  相似文献   

18.
The reaction kinetics of wood (Corsican pine) with acetic, propionic, succinic, and hexenyl succinic anhydride dissolved in pyridine were investigated. To determine reaction kinetics, anhydride depletion of the reactive liquid was monitored. This approach allows to collect a complete sequence of kinetic data from a single experiment. The results carry information on reaction kinetics without allowing for a precise determination of reaction turnover vs time. For all anhydrides investigated, the reaction kinetics of wood samples of different size (300 μm–4 mm) do not depend on sample size, hence the reaction is activation- not diffusion-controlled. All results are consistent with a remarkably simple model of purely activation-controlled reaction kinetics with a single activation energy. Activation energies were determined. The result for propionic anhydride agrees with an earlier investigation based on weight gain of reacted wood. Received 16 March 1999  相似文献   

19.
为解决2,3,4,4′-四羟基二苯甲酮(4HBP)的传统合成方法中原料易氧化的问题,采用羟基保护方法,以1,2,3-三甲氧基苯(TMB)和对甲氧基苯甲酸(p-AA)为原料、伊顿试剂为催化剂,1,2-二氯乙烷为溶剂,首次合成重要的中间体化合物2,3,4,4′-四甲氧基二苯甲酮(4TMP),然后在BBr3/CH2Cl2体系、无水无氧、低温的条件下,将4TMP进行脱甲基反应高效合成了目标产物4HBP,目标产物收率约为86.4%,纯度≥97.59%,各金属离子均小于18.60mg/kg。通过红外光谱、核磁共振谱、质谱等方法确证了中间产物和目标产物的结构。  相似文献   

20.
以插入Taq DNA聚合酶基因的pET-24a表达质粒转化E.coli菌株,表达Taq DNA聚合酶,用反复冻融的方法裂解菌体.表达产物为可溶性蛋白,采用Duo-Flow系统(Bio-Rad)及S柱,Tris缓冲液pH为7.5.以0-1 mol/L盐梯度洗脱方式,收集洗脱峰.透析去盐可得到高纯度的产品.经PCR反应与商品Taq酶的一个活性单位相比较,重组的Taq酶活性有1个单位.用该方法可以从1 L培养液中分离得到5.51 mg产品.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号