首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 93 毫秒
1.
天然橡胶原位接枝炭黑的分散性研究   总被引:1,自引:0,他引:1  
采用原位固相接枝方法,使在高温和强剪切作用下降解的天然橡胶接枝到炭黑表面.采用透射电镜(TEM)、原子力显微镜(AFM)等方法观察了接枝前后的炭黑粒子形貌变化,发现未接枝炭黑以微米级的附聚体形式存在,而由于炭黑聚集体被强剪切力部分破坏,接枝炭黑的聚集程度明显减弱,粒子的尺寸减小.采用激光光散射粒度仪对接枝前后炭黑的粒度进行分析,接枝炭黑的体积平均粒径为164 nm,远小于测得的原炭黑的粒径797 nm.采用沉降法、透光率法及zeta电位测量研究了接枝改性对炭黑在溶剂中的分散性及分散稳定性的影响,结果表明,接枝炭黑在接枝分子的溶剂中的分散性变好,分散稳定性提高.  相似文献   

2.
纳米炭黑复合涂料的制备及其耐蚀性能;纳米炭黑;复合涂料;制备;耐蚀性  相似文献   

3.
聚丙烯酸酯接枝炭黑的合成,表征及其应用   总被引:5,自引:1,他引:4  
探讨聚丙烯酸酯接枝炭黑的合成条件及其影响因素。用红外光谱和元素分析对接枝物进行了表征,通过ζ-电位法,透光率和SEM研究了接枝炭黑的分散稳定性。接枝炭黑分散于水性无皂涂料中形成黑色涂料具有良好的综合性。  相似文献   

4.
改性炭黑及其增强橡胶的研究   总被引:1,自引:0,他引:1  
从炭黑在橡胶中的应用出发,介绍了炭黑的结构、各种炭黑改性的方法以及改性炭黑对橡胶物理机械性能的影响。  相似文献   

5.
原位接枝炭黑/天然橡胶复合材料的制备及性能   总被引:4,自引:0,他引:4  
采用原位固相接枝方法,使在高温和强剪切作用下降解的天然橡胶接枝到炭黑表面.通过对接枝前后炭黑填充天然橡胶的性能对比发现,原位接枝炭黑不但能提高天然橡胶的硫化速度,还能提高拉伸强度,定伸应力和撕裂强度等;动态力学性能的测试结果表明接枝炭黑填充的天然橡胶中接枝炭黑网络化程度较低,这些结果主要归因于接枝炭黑在橡胶基体中分散性的改善及炭黑与橡胶之间作用力的增加.  相似文献   

6.
炭黑接枝是常用的炭黑表面改性方法。讨论了最新的炭黑接枝方法,主要包括二次接枝法、γ-射线辐射接枝、三氯乙酰基团与六羰基钼引发乙烯基单体聚合接枝,偶联接枝与聚合物交联及其它方法;并对接枝炭黑在新材料领域的臆用作了介绍。  相似文献   

7.
丙烯酰胺在炭黑表面接枝聚合研究   总被引:4,自引:0,他引:4  
利用Ce^4+和羟甲基化炭黑组成的氧化还原引发体系,探讨了丙烯酰胺在炭黑表面的自由基水溶液接枝聚合机理。研究表明:单体浓度、硝酸浓度和铈盐用量直接影响丙烯酰胺在炭黑表面的接枝聚合,FTI和TEM分析证明:改性炭黑表面存在着聚丙烯酰胺。改性炭黑粒子的Zeta电位值与未改性炭黑粒子相同,但它与水组成的分散体具有极好的分散稳定性。  相似文献   

8.
利用高分辨透射显微镜分别对煤和生物质快速热解炭黑、天然气非催化部分氧化小试装置炭黑和工业装置炭黑、商业天然气炉法炭黑和煤焦油炉法炭黑等六种样品的形貌结构进行了表征;基于常压热重分析仪非等温法(50?800℃)对炭黑的着火点、氧化反应速率进行了研究,获得了炭黑的氧化反应动力学参数.研究表明,不同的炭黑理化性质差异较大,煤...  相似文献   

9.
利用正丁基锂(n-BuLi)与炭黑(CB)表面含氧基团反应制得了表面含-OLi基团的反应型炭黑,以该炭黑与聚氧乙烯-聚氧丙烯-聚苯乙烯(PEO-PPO-PS)多嵌段聚合物组成的阴离子引发体系作活性中心,研究了苯乙烯在炭黑表面的阴离子接枝聚合。FT-IR,TEM和DSC分析表明在接枝炭黑表面存在苯乙烯的聚合物。接枝炭黑在甲苯中有良好的分散稳定性。  相似文献   

10.
超声引发自由基聚合制备聚苯乙烯磺酸钠接枝炭黑   总被引:1,自引:0,他引:1  
通过在超声环境下,单体苯乙烯磺酸钠发生自由基聚合,生成的聚合物长链自由基被炭黑表面捕获,制备聚合物接枝炭黑.借助红外光谱、热重、粒度、透射电镜和zeta电位分析对该接枝炭黑进行表征.同时研究超声条件对接枝率的影响.结果表明,单体聚合并接枝到炭黑表面,同时炭黑的附聚体和一些大的聚集体结构被超声破碎,平均粒径大为减小;在300W超声波输出功率下,反应1h后,接枝率达到12.8%并趋于稳定.由于接枝分子链上磺酸基的存在,接枝炭黑在水中的分散稳定性显著改善.  相似文献   

11.
丙烯酸在炭黑表面接枝聚合研究   总被引:18,自引:2,他引:18  
丙烯酸在炭黑表面接枝聚合研究吴壁耀,刘安华,邵兰英,蒋子铎(武汉化工学院精细化工系,武汉,430073)关键词接技聚合,炭黑,Zeta电位,表面改性炭黑是由大量的原生粒子聚集而成的.该聚集体表面积大、表面又含有丰富的极性基因,故在炭黑/涂料树脂体系中...  相似文献   

12.
The radical graft polymerization of vinyl monomers from carbon black initiated by azo groups introduced onto the surface was investigated. The introduction of azo groups onto carbon black surface was achieved by three methods: the reaction of 2,2′-azobis[2-(2-imidazolin-2-yl)propane] (AIP) with (1) epoxide groups, which were introduced by the reaction of carbon black with chlorometh-yloxirane; (2) acyl chloride groups, which were introduced by the reaction of carboxyl groups on the surface with thionyl chloride; and (3) 3-chloroformyl-1-cyano-1-methylpropyl groups, which were introduced by the reaction of carbon black with 4,4′-azobis(4-cyanovaleric acid) and then thionyl chloride. The amount of azo groups introduced onto the surface by the above methods was determined to be 0.07-0.19 mmol/g. The graft polymerization of methyl methacrylate was found to be initiated by azo groups introduced onto the carbon black surface. During the polymerization, poly(methyl methacrylate) was effectively grafted onto carbon black through propagation of the polymer from the radical produced on the surface by the decomposition of the azo groups. The percentage of grafting using carbon black having azo groups introduced by method 1 increased to 40%. It was also found that the graft polymerization of several vinyl monomers such as styrene, acrylonitrile, and acrylic acid was initiated by the azo groups introduced onto the surface and the corresponding polymer was effectively grafted onto the surface. Furthermore, the effect of the amount of carbon black having azo groups on the graft polymerization was investigated.  相似文献   

13.
乙烯基单体在炭黑表面上的接枝聚合   总被引:3,自引:0,他引:3  
讨论了分别在铈离子体系,正丁基锂体系,过渡金属离子乙酰丙酮铜(Ⅱ)以及焦磷酸络锰(Ⅲ)体系的作用下,炭黑与乙烯基单体的接枝聚合.研究了引发剂浓度、单体浓度、反应时间对接枝聚合反应的影响.利用FT IR分析确证了炭黑表面的接枝反应,利用TEM表征了接枝炭黑的形态.结果表明,在所研究的多种炭黑表面接枝聚合体系中,正丁基锂体系的接枝率最高,可达200%.而各种氧化还原体素的接枝率只能达到30%左右.表面接枝后的炭黑在介质中的分散稳定性明显改善.  相似文献   

14.
丙烯酸乙酯在炭黑表面的阴离子接枝聚合研究   总被引:2,自引:0,他引:2  
丙烯酸乙酯在炭黑表面的阴离子接枝聚合研究蒋子铎,刘长生,刘安华,吴璧耀(武汉化工学院精细化工系武汉430073)关键词炭黑,丙烯酸乙酯,阴离子聚合,接枝聚合由于炭黑粒子自聚力强,存在难分散、易絮凝的特点,影响其在高分子材料中的分散和分散稳定性.对此国...  相似文献   

15.
近年来,炭黑粒子在水性体系中的分散稳定性倍受人们关注。研究认为影响炭黑分散稳定的主要因素为炭黑颗粒之间的相互作用力(包括电磁力、静电排斥力和空间位阻力等)和炭黑粒子与分散介质之间的相互作用力。目前,实现炭黑在水性体系中良好分散所采用的方法主要有炭黑氧化法、分散剂法和炭黑高分子接枝法,其中以炭黑高分子接枝方法效果最佳。  相似文献   

16.
The radical graft polymerization of vinyl monomers onto carbon black initiated by a redox system consisting of ceric ion and carbon black having alcoholic hydroxyl groups was investigated. The introduction of alcoholic hydroxyl groups onto the carbon black surface was achieved by the reaction of carbon black with alcoholic hydroxyl radicals, formed by the reaction of alcohol with benzoyl peroxide. The rate of the polymerization of acrylamide (AAm) initiated by the redox system was found to increase in the following order of hydroxyl groups: 1-hydroxyoctyl < 1-hydroxypropyl < 1-hydroxyethyl < hydroxymethyl < 1-hydroxy-1-methylethyl. In the redox polymerization, poly-AAm was effectively grafted onto carbon black by propagation of the polymer from the radical formed by the reaction of ceric ions with the alcoholic hydroxy groups. The percentage of grafting increased with increasing conversion. By use of this redox system, poly(acrylic acid), polyacrylonitrile, and poly(N-vinyl-2-pyrrolidone) could be grafted onto carbon black, but poly(methyl methacrylate) and polystyrene could not be so grafted. The graft polymerization of AAm by use of a redox system consisting of ceric ion and PVA-grafted carbon black was also investigated.  相似文献   

17.
The cationic ring-opening polymerization of trioxane and 1,3-dioxolane was found to be initiated by CO+CIO4? groups on a carbon black surface, which were introduced by the reaction of COCI groups with AgCIO4. The activation energy of the ring-opening polymerization of trioxane was estimated to be 15.5 kcal/mol. In the polymerization system, poly(oxymethylene) and poly(1,3-dioxolane) formed were effectively grafted onto carbon black depending upon the propagation of these polymers from the carbon black surface; for instance, the grafting ratio of poly(oxymethylene) onto carbon black increased with an increase in conversion and went up to about 180%. Although the grafted chain of poly(oxymethylene) was subject to stepwise thermal depolymerization from the chain ends, the thermal stability of poly(oxymethylene)-grafted carbon black was improved by acetylation of hemiformal end groups. The molecular weight of ungrafted poly(oxymethylene) formed in the polymerization was determined to be 1.8–2.0 × 104. Furthermore, the copolymerization of trioxane with 1,3-dioxolane, styrene, and other comonomers initiated by CO+CIO4? groups and the thermal stability of these acetal copolymer-grafted carbon black were investigated.  相似文献   

18.
The ring-opening copolymerization of alkylene carbonate with cyclic acid anhydride was found to be initiated by carbon black containing potassium carboxylate (COOK) groups to give an alternating polymer, i.e., polyester. The polyester was propagated from COOK groups and effectively grafted from carbon black surface: e.g., the grafting ratio of polyester from ethylene carbonate (EC) and phthalic anhydride (PAn) went up to over 100%. On the other hand, the initiating activity of alkali metal carboxylate groups increased, depending on the alkali metal countercation, in the following order: COOLi < COONa < COOK < COORb < COOCs. This order was in agreement with that of increasing electropositivity of the counteraction. The activation energy of the copolymerization of EC with PAn was determined to be 26.3 kcal/mol. The rate of the copolymerization was accelerated in an aprotic solvent such as N-methyl-2-pyrrolidone. Furthermore, the effect of solvent and polymerization temperature on the grafting ratio of polyester was investigated.  相似文献   

19.
The functionalization of carbon black surface with atom transfer radical polymerization (ATRP) initiating sites and subsequent ATRP of n‐butyl acrylate (n‐BA) and t‐butyl acrylate (t‐BA) from the surface of carbon black is reported. The polymerizations were carried out using CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as the primary catalytic system in anisole at 70 °C. The initiator density on carbon black surface was tuned and the effect of initiator density on the polymers grafted on the surface was illustrated. Polymerizations were also performed in the presence of a sacrificial initiator to indirectly monitor the molecular weight evolution of polymers formed in the system. Block copolymerization of t‐BA initiated from poly(n‐BA) grafted carbon black was conducted to achieve water‐dispersible carbon black composites after cleavage of the t‐butyl groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4695–4709, 2005  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