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铬酸引发丙烯腈与苎麻纤维接枝共聚反应 总被引:4,自引:0,他引:4
棉、麻类织物通过与乙烯类单体接枝共聚可以提高染色性、皱折回复性、耐磨性、防污性等[‘j.纤维素接枝共聚物的合成始于50年代,目前研究最多的是乙烯类单体通过自由基活性中间体与纤维素进行接技共聚,但此法存在一个突出的问题是在接技共聚的同时生成大量均聚物.铬酸(下文用Cr’“表示)是公认的强氧化剂,据报道[’-‘j,它单独存在时并不能引发乙烯类单体聚合,如果用Cr‘”引发乙烯类单体与纤维素接技共聚,均聚物的生成量将会减少.本文以Cr’”为引发剂,将丙烯睛(AN)与艺麻纤维进行接技共聚,考查不同条件对接技率及均聚… 相似文献
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In this work,a novel sugar-containing copolymer was synthesized by the copolymerization of α-allyl glucoside(AG) with acryloniutrile(AN).The copolymers were characterized by NMR Spectroscopy.It was found that acrylonitrile-based copolymers containing as high as 22wt.% of α-allyl glucoside can be synthesized by the free radical solution copolymerization of the two monomers in DMSO with AIBN as initiator. 相似文献
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Hou Chen Delong Liu Naiyi Ji Zhi Tan Guangxi Zong Rongjun Qu 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(4):284-290
Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) initiated by ethyl 2-bromoisobutyrate (EBiB) was approached for the first time in the absence of oxygen and in the presence of air, using a novel catalyst system based on SmBr3·6H2O/isophthalic acid complexes and using ascorbic acid (VC) as a reducing agent. Both the polymerization in the absence of oxygen and in the presence of air proceeded in a well-controlled manner as evidenced by kinetic studies. Compared with the polymerization in the absence of oxygen, the polymerization in the presence of air provided rather slow reaction rate and showed better control of molecular weight and its distribution under the same experimental conditions. The polymerization apparent activation energies in the absence of oxygen and in the presence of air were calculated to be 47.1 and 51.3 kJ·mol?1, respectively. A slow polymerization rate and a broad polydispersity index were observed using anisole and toluene instead of DMF as solvent. Polyacrylonitrile obtained was successfully used as a macroinitiator to proceed the chain extension polymerization of styrene via AGET ATRP in the presence of air. 相似文献
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AM-DMDAAC共聚物的合成 总被引:17,自引:0,他引:17
研究了丙烯酰胺(AM)与阳离子单体二甲基二烯丙基氯化铵(DMDAAC)的水溶液聚合,考察了引发剂用量、单体总浓度,pH值,n(AM):n(DMDAAC)对聚合物阳离子度和特性粘度的影响。并对产物进行了IR和热分析。 相似文献
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丙烯腈 (AN)聚合通常采用自由基和阴离子聚合两种 .它们存在催化剂活性低 ,用量大等缺点 .关于丙烯腈的配位聚合研究报道则较少 .最近 ,有报道发现二价稀土化合物可以催化丙烯腈聚合 ,但催化活性较低[1 ,2 ] .本文以二茚基钇 -铝双金属配合物 (C9H7) 2 Y(μ- Et) 2 Al Et2(以下以 Y- Al代表 )为 AN聚合催化剂 ,发现它单独可以催化 AN聚合 .当外加酚钠(Ph ONa)时 ,可以大大提高聚丙烯腈 (PAN)的产率及分子量 .研究了单体浓度、催化剂浓度、温度、时间等对 AN聚合的影响 ,并对其引发机理进行了研究 .Y- Al的合成及聚合方法见文献 [3… 相似文献
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SynthesisandStructureof 1-Cyclopentylindenyl Lanthanide(II) Complexes and Their Catalytic Behavior for Polymerization of Acrylonitrile 总被引:3,自引:0,他引:3
IntroductionGreatprogresshasbeenmadeinthechemistryofdi valentorganolanthanidecomplexes .Avarietyofnewclassesofcomplexeshavebeensynthesizedandwidelyusedinorganicsynthesisandpolymerchemistry .1 6 Itwasnoticedthatmostoftheworkpublishedisfocusedonthecomplexe… 相似文献
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二(叔丁基环戊二烯基)钕甲基配合物催化丙烯腈聚合 总被引:7,自引:0,他引:7
二(叔丁基环戊二烯基)钕甲基配合物催化丙烯腈聚合任劲松,扈晶余,沈琪(中国科学院长春应用化学研究所稀土化学与物理开放实验室长春130022)(苏州大学化学系苏州)关键词丙烯腈,配位聚合,钕配合物丙烯腈聚合通常采用BF_3、TiCl_4、过氧化苯甲酰 ̄... 相似文献
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Free radical polymerization of acrylonitrile (AN) in ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), 2,2;m1-azobisisobutyronitrile (AIBN) as initiator was investigated. Early investigations on polymerizations using ionic liquids indicate that they serve as especially good solvents to achieve high molecular weight polymers. Free radical polymerizations result in higher molecular weight polymers, for ionic liquids have low chain transfer constants and act to stabilize the active radical during the process of polymerization. The thermal stability of polymers synthesized in ionic liquids have be improved obviously than that in traditional solvents. 相似文献
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四配位硅单体及其共聚物的制备和结构表征 总被引:4,自引:0,他引:4
研究了直接从无定形二氧化硅出发, 与乙二醇、氢氧化钾反应, 生成高反应活性的五配位硅钾化合物, 并以此为原料与含活泼氯的3-氯丙烯反应制备出含双键官能团的四配位硅单体. 讨论了合成单体的条件如温度、反应时间、反应物浓度、溶液pH值及溶剂等因素的影响. 然后以该四配位硅单体与甲基丙烯酸甲酯(MMA)在偶氮二异丁腈(AIBN)作引发剂下进行自由基聚合得到支链含硅共聚物. 并借助于红外光谱(IR)、核磁共振(13C和1H, 29Si)、能谱元素分析对合成的单体进行了结构表征; 用红外光谱(IR)、热失重谱(TG)、差示扫描量热谱(DSC)、凝胶渗透色谱法(GPC)等现代测试手段对支链含硅共聚物进行了结构表征及热性能分析. IR表明四配位硅单体在1646 cm-1处是C=C的伸缩振动吸收峰, 在共聚物中此峰消失; TG表明共聚物在249.6 ℃才开始失重, 552 ℃有机部分失重完毕; GPC分析表明共聚物的数均分子量为8.7万. 相似文献
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In addition to the usual polydispersity with respect to molar mass, copolymers show chemical polydispersity. Thus, the species present may not be adequately characterized by a single variable, and a divariate distribution function has to be applied for describing the composition of the copolymer. In continuous thermodynamics, such continuous distribution functions are used directly (without splitting into pseudocomponents) for describing the composition of complex multicomponent systems. Whereas until now usually only one distribution variable has been used in continuous thermodynamics, consideration of copolymers requires an extension to divariate distribution functions. Continuous thermodynamics is generalized to divariate distribution functions in this paper. The liquid-liquid equilibrium of copolymer solutions is considered as a specific example. 相似文献
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以K2S2O8-NaHSO3 氧化还原体系为引发剂, 采用水相沉淀自由基聚合法合成丙烯腈(AN)-醋酸乙烯酯(VAc)无规共聚物[P(AN-co-VAc)], 然后在KOH水溶液中进行P(AN-co-VAc)中VAc单元的选择性水解, 再与磷酸和尿素进行磷酰化反应, 制备无卤阻燃丙烯腈共聚物. 用核磁共振氢谱(1H NMR)、傅里叶变换红外光谱(FTIR)、差示扫描量热(DSC)和热重分析(TGA)对聚合物结构及热性能进行表征, 用凝胶渗透色谱(GPC)测定了P(AN-co-VAc)的分子量及其分布, 并利用FTIR和扫描电子显微镜(SEM)对无卤阻燃丙烯腈共聚物的炭残渣进行分析. 结果表明, VAc与AN发生共聚反应, 制得了P(AN-co-VAc), 随着KOH水溶液pH值的增大, P(AN-co-VAc)中VAc单元迅速水解; DSC分析结果表明, 随着共聚物中VAc单元含量的增大, 共聚物的环化放热分解峰值温度(Tp)增大, 当VAc单元的质量分数为25%时, Tp最大值高达328 ℃, 而阻燃丙烯腈共聚物的Tp高达340 ℃; TGA分析结果表明, 阻燃共聚物在800 ℃时的炭残渣量高达55%以上, 远高于P(AN-co-VAc)的41%, 具有良好的成炭性; 炭残渣的FTIR及SEM结果表明, 阻燃丙烯腈共聚物的阻燃属于凝聚相阻燃. 相似文献
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Synthesis and Structure of 1—Cyclopentylindenyl Lanthanide(Ⅱ)Complexes and Their Catalytic Behavior for Polymerization of Acrylonitrile 总被引:1,自引:0,他引:1
The reaction between K(1‐C5H9C9H6) and anhydrous LnCl3 (Ln=Sm, Yb) in the molar ratio of 2:1 in THF with subsequent treatment by Na‐K alloy afforded (1‐C5H9C9H6)2Ln‐(THF)n(Ln=Sm, n=1; Ln=Yb, n=2), while the reaction of Sml2 with K(1‐C5H9C9H6) in the molar ratio of 1:2 in THF gave the anionic complex K(1‐C5H9C9H6)3Sm(THF)3. The X‐ray structure of (1‐C5H9C9H6)2Yb(THF)2 showed that central metal Yb is coordinated by two cyclopentadienyl rings of 1‐cyclopentylindenyls and two oxygen atoms from two tetrahydrofuran molecules to form pseudo‐tetrahedral coordinate geometry. All these complexes are active for the polymerization of acrylonitrile. 相似文献