共查询到19条相似文献,搜索用时 46 毫秒
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一缩二乙醇二甲基丙烯酸酯对真丝接枝的反应性 总被引:3,自引:0,他引:3
研究了一缩二乙二醇二甲基丙烯酸酯在空气存在下,用过硫酸钾(KPS)在水液 中对真丝的接枝。对接枝的条件,如单体、引发剂、甲酸(FA)和乳化剂OP的浓度以 及温度和时间对接枝率的影响进行了测试。发现了较佳的接枝条件是:温度 = 80 ℃,时间 = 30 min,[KPS] = 1.85% (owm),[OP] = 1% (owf),[FA] = 0.2%。 接枝率的大小可以用单体浓度来调节,接枝活化能是86.94 kJ/mol。 相似文献
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一缩二乙二醇二甲基丙烯酸酯接枝真丝的结构 总被引:10,自引:0,他引:10
通过电子扫描电镜 (SEM)、红外光谱 (IR)、双折射、X 射线衍射及氨基酸分析等手段 ,研究了真丝用一缩二乙二醇二甲基丙烯酸酯 (P 2 )接枝后其结构与接枝率之间的关系 .氨基酸分析结果表明P 2接枝主要在真丝大分子中酪氨酸、丝氨酸、组氨酸和精氨酸的NH2 、OH和—NH—活性基团上 .通过X 射线衍射分析 ,P 2接枝并不直接影响结晶区 ,但引起分子取向的下降 ,接枝后真丝双折射下降说明接枝后因大分子取向度下降 ,接枝真丝的红外光谱显示出真丝具有 β折迭结构和P 2高聚物的结构特征峰 ,从而说明P 2接枝在纤维的无定型区内部进行 .当接枝率大于 35 %时 ,纤维的表面覆盖了一层高聚物 (P 2 ) ,并且纤维的横截面表现出明显的分纤现象 ,接枝真丝的红外光谱表明了纤维与P 2重叠吸收峰 ,说明了P 2在丝纤维内部接枝聚合 . 相似文献
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甲基丙烯酸甲酯与海藻酸接枝共聚合反应的研究 总被引:3,自引:0,他引:3
研究了甲基丙烯酸甲酯(MMA)在过硫酸钾(KPS)-尿素(U)引发体系作用下与海藻酸钠的接枝共聚反应,红外吸收光谱证明了接枝共聚物的结构。结果表明,当[KPS]=[U]=4.0×10~(-3)mol/L、[MMA]=4.0×10~(-1)mol/L、海藻酸钠用量为20g/L,50℃反应5小时,接枝率及接枝效率较高。 相似文献
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罗布麻纤维与丙烯酸酯类接枝共聚物结构和性能的研究 总被引:5,自引:0,他引:5
本文以氧化还原体系引发丙烯酸甲酯(MA)、丙烯酸乙酯(EA)、丙烯酸丁酯(BA)与罗布麻纤维的接枝共聚反应,用IR、SEM和X-射线衍射等手段表征了接枝纤维的结构。与纯罗布麻纤维相比较,接枝纤维具有较高的断裂伸长率和较低的杨氏模量,柔顺性增加;耐酸、碱能力随接枝率的增加而提高,但吸湿率不降。 相似文献
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聚苯乙烯-甲基丙烯酸甲酯接枝共聚物的合成和表征 总被引:3,自引:0,他引:3
<正> 聚苯乙烯(PS)和聚甲基丙烯酸甲酯(PMMA)都是研究得十分深入的聚合物。它们的接枝共聚物,虽然在基础研究中是十分有兴趣的对象,但因传统的合成方法不能得到结构确定的产物,同时难于与伴生的均聚物分离,进展不大。近年来随着大分子单体方法和极性单体活性阴离子聚合的发展,具有确定结构的接枝共聚物PS-g-PMMA的合成逐步成为可能。例如:Ishizu采用阴离子聚合合成带乙烯基的PMMA大分子单体,再与苯乙烯自由基共聚的路线,Ballegoole等和Watanable分别采用主干接枝法,即用自 相似文献
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甲基丙烯酸双酯改性真丝的热性质 总被引:2,自引:0,他引:2
众所周知 ,真丝绸因具有柔和的光泽、细腻的手感、良好的舒适性和保健性而素有“纤维皇后”的美称 .但其极易起毛起皱 ,尤其是湿态下更为严重 ,这大大影响了它的实用价值 .70年代以来 ,人们就开始用化学整理的方法提高和改善真丝绸的各种性能 ,但所用整理剂含有游离甲醛 ,或经其整理后织物会释放对人体有害的甲醛 .随着人们生活水平的提高 ,人们对“绿色纺织品”的需求越来越迫切 ,要求整理向低甲醛、无甲醛方向发展 .近年来 ,人们对用单烯类和环氧化合物对真丝进行改性的研究作了大量的工作[1~ 4] ,这些改性在某种程度上能够改善真丝的性… 相似文献
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Munmaya K. Mishra 《高分子科学杂志,C辑:聚合物评论》2013,53(2):193-220
Modification of the properties of textile fibers in order to get a fiber of improved textile performance is the subject of study of several groups of scientists and technologists [1–4]. Of the several methods available, grafting promises to be a potentially effective means of altering the fiber properties through the added polymer formed in situ without destroying the basic properties of the parent fiber. Copolymerization is attractive to chemists as a means of modifying macromolecules since, in general, degradation can be minimized. The desirable properties of the polymer are retained and copolymerization provides additional properties through the added polymer. The added polymer may be formed in situ by polymerization of a monomer or monomers, by condensation of reactants, or by the deposition of preformed polymer. 相似文献
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采用接枝量、ATR-IR、SEM、与水接触角、溶血试验和再钙化时间等测试手段研究了电火花引发甲基丙烯酸β-羟乙酯(HEMA)表面接枝低密度聚乙烯(LAPE)薄膜的接枝聚合反应影响因素、表面结构和血液相容性。结果表明,电火花能有效引发HEMA在LDMA薄膜表面接枝聚合反应,随接枝聚合反应时间延长、单体浓度的增大。接枝量增大。随反应温度升高,接枝量增大到一最大值后,进一步升高反应温度,接枝量下降,最佳接枝聚合温度为60℃当在60℃单体φ=5%水溶液是反应2h时,经空气气氛和1.5kV电火花预处理72s和LDPE薄膜表面接枝量可达169ug/cm^2。接枝改性后LDPE薄膜与水的接触下降,亲水性增加,溶血程度减小,再钙化时间延长,血液相容性得到改善。 相似文献
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溶剂萃取动力学的研究III. 氯化铀酰在盐酸和磷酸三丁酯之间传质过程 总被引:2,自引:0,他引:2
本文采用上升液滴法, 研究了氯化铀酰在盐酸介质和磷酸三丁酯(TBP)之间的传质过程. 在一定浓度的盐酸溶液中, TBP 萃取铀的速率与[U] 成正比; 反萃速率与[U] 成正比, 而与[TBP] 成反比. 在温度为20~40 范围内分别测测定了萃取和反萃反应的活化能, 它们的差值与由萃取平衡分配 温度关胤系测得的焓变相符,可以认为, 萃合物UO2Cl2TBP 的生成和离解都是分步进行的中间 物是CU2Cl2TBP; 萃取速率的控制步骤是UO2Cl22TBP 的生成反应, 而反萃速率 相似文献
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利用传统自由基聚合法,在四氢呋喃溶液中自由基引发聚合甲基丙烯酸丁酯单体而得到ω-羧基-甲基丙烯酸丁酯低聚物(CTBMA)(分子量在1500左右);利用CTBMA末端酯基的反应特性,在二氧六环/水/KOH混合溶液中皂化CTBMA,使之转化为α,ω-羧基甲基丙烯酸丁酯低聚物(di-CTBMA);研究了溶剂的类别、反应时间等反应条件对皂化产物结构的影响;利用MALDI-TOF-MS及LSIMS对皂化各阶段产物进行了分析监测.实验表明,在适当的皂化条件下,CTBMA皂化时主要为末端酯基转化为羧基,相应得到的产物di-CTMBA具有很好的结构特性,其官能团度(functionality)接近2. 相似文献
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固液相烃基化反应的研究 I.以碳酸钾为碱的丙二酸乙二酯和氰乙酸乙酯的烃基化反应 总被引:1,自引:0,他引:1
The alkylation of diethyl malonate and ethyl cyanoacetate using powdered potassium carbonate asa base in the absence of solvent and other catalyst is studied. The features of this method are: simple preparative procedure, reproducible yield and easy control of monoalkylation. The reaction mechanism is discussed briefly. 相似文献
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Yutaka Kawahara 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(S7-S8):359-363
Abstract Graft polymerization of methacrylamide (MAA) onto wild silk fibers was performed and the influence of pigments on graft polymerization was investigated. The pigments of Chinese oak silk and Japanese oak silk inhibited the polymerization of MAA. The inhibitory power of the pigments of Chinese oak silk was serious as compared with the pigments of Japanese oak silk. Therefore, MAA polymer add-on of Chinese oak silk fibers became smaller than that of Japanese oak silk fibers. 相似文献
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Abstract The graft copolymerization of methyl methacrylate (MMA) onto mulberry silk fibers was studied in aqueous solution using the acetylacetonate oxovanadium (IV) complex. The rate of grafting was investigated by varying the concentration of the monomer and the complex, the acidity of the medium, the solvent composition of the reaction medium, the surfactants, and the inhibitors. The graft yield increases with increasing concentration of the initiator up to 8.75 × 10?5 mol/L, of the monomer up to 0.5634 mol/L, and thereafter it decreases. Among the various vinyl monomers studied, MMA was found to be most suitable for grafting. Grafting increases with increasing concentration of HCIO4 and with increasing temperature. Inhibitors like picryl chloride and hydroquinone significantly decrease the extent of grafting. Alcoholic solvents at a solvents/water ration of 10:90 seem to constitute the most favorable medium for grafting. A suitable reaction scheme has been proposed, and the activation energy calculated from the Arrhenius plots. 相似文献
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Yue Su Shufen Zhang Heping Li Bin Zhao Kexin Tian Zhiming Zou 《Molecules (Basel, Switzerland)》2022,27(18)
As a biocompatible biomaterial, bagasse xylan (BX) has been widely used in the biomedical field. The low biological activity of andrographolide (AD) restricts its development, so AD with certain anticancer activity is introduced. We use chemical modification methods such as grafting and esterification to improve the biological activity and make a novel anticancer nanomaterial. On the basis of the esterification of a mixture of BX and AD with folic acid (FA), a novel anticancer nanoderivative of bagasse xylan/andrographolide folate-g-dimethylaminoethyl methacrylate (DMAEMA)/diethylene glycol dimethacrylate (DEGDMA) nanoparticles (FA-BX/AD-g-DMAEMA/DEGDMA NPs) was synthesized by introducing DMAEMA and DEGDMA monomers through a graft copolymerization and nanoprecipitation method. The effects of reaction temperature, reaction time, the initiator concentration and the mass ratio of FA-BX/AD to mixed monomers on the grafting rate (GR) were investigated. The structure of the obtained product was characterized by FTIR, SEM, XRD and DTG. Further, molecular docking and MTT assays were performed to understand the possible docking sites with the target proteins and the anticancer activity of the product. The results showed that the GR of the obtained product was 79% under the conditions of the initiator concentration 55 mmol/L, m (FA-BX/AD):m (mixed monomer) = 1:2, reaction temperature 50 °C and reaction time 5 h. The inhibition rate of FA-BX/AD-g-DMAEMA/DEGDMA NPs on human lung cancer cells (NCI-H460) can reach 39.77 ± 5.62%, which is about 7.6 times higher than that of BX. Therefore, this material may have potential applications in the development of anticancer drug or carriers and functional materials. 相似文献