共查询到20条相似文献,搜索用时 31 毫秒
1.
Hui PAN Zhi Jun ZHANG Hong Xin DANG State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou Lab. of Special Functional Material Henan University Kaifeng 《中国化学快报》2005,16(10)
Environmental pollution is one of headache problems in leather tanning industry.Traditionally chrome tanning was the predominant technique used in leather making.However,chrome tanning is being substituted due to its pollution and scarcity of resource.The study of non-chrome tanning in leather shows more interests with the development of nanomaterial and nanotechnology.J.Z.Ma et al.have reported that organic–montmorillonite nanocomposite can raise the shrinkage temperature of pickled pigskin… 相似文献
2.
磺化苯乙烯-马来酸酐共聚物 总被引:4,自引:0,他引:4
磺化苯乙烯-马来酸酐共聚物是由苯乙烯-马来酸酐共聚物直接磺化并中和成钠盐制备。由于它分子中含有很多磺酸及羧酸负离子,因此,是一很好的阴离子聚电解质,被广泛用于泥浆稀释剂、水泥添加剂和皮革鞣剂等。 相似文献
3.
4-PEG接枝苯乙烯-马来酸酐交替共聚物的合成及功能化 总被引:2,自引:0,他引:2
采用普通自由基聚合和可逆加成一断裂链转移(RAFT)自由基聚合方法合成了对位PEG取代苯乙烯(PEG-g-St)和马来酸酐的交替共聚物(P((PEG—g—St)-alt-MA)),”CNMR分析表明PEG-g-St和马来酸酐单元采取交替的序列结构.利用反应性基团-马来酸酐单元的水解以及胺解可以制备功能性的PEG聚合物.以月桂胺为模型小分子研究了该聚合物的胺解,得到4-PEG-苯乙烯与羧酸基团以及疏水烷烃的交替序列聚合物,该双亲聚合物在水溶液中形成组装体. 相似文献
4.
Minoru Matsuda Katsuhiro Abe 《Journal of polymer science. Part A, Polymer chemistry》1968,6(6):1441-1447
A polymerization was induced with a charge-transfer type of complex consisting of styrene and maleic anhydride in the presence a solvent such as ethyl benzene, cumene, or p-cymene. No polymer was obtained either when the solvent was missing from the polymerization system or when benzene, toluene, or xylene, which are relatively stable to hydrogen abstraction, was added to the polymerization system. An effective initiation, however, took place when cumene or p-cymene, each of which has a labile hydrogen on an α carbon, was added. On the basis of elementary analysis and infrared spectroscopy the formation of copolymer containing substantially equimolar amounts of styrene and maleic anhydride was ascertained. This polymerization was inhibited by the addition of DPPH, suggesting that the system styrene–maleic anhydride–cumene functions much as a conventional free-radical initiator. On the other hand, when a solution of cumene and liquid sulfur dioxide was added to the polymerization system, polystyrene was obtained. This polymerization was inhibited by the addition of a base such as dimethyl-formamide or dimethyl sulfoxide, indicating that the polymerization proceeds through carbonium ion intermediates. The addition of ethyl benzene or of p-cymene brought about the same result as cumene. It is conceivable that the polymerization is induced by the abstraction of hydrogen attached at the α position of cumene by means of the charge-transfer complex of styrene and maleic anhydride. 相似文献
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Yitao Yu Qinghua Zhang Zhenxi Wang Xiaoli Zhan Ren He Wentao Zhang 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(1):60-66
A process for reversible addition-fragmentation chain transfer (RAFT) radical polymerization in a mini-emulsion system stabilized by ammnolyzed poly(styrene-alt- maleic anhydride) copolymer (SMA) as an amphiphilic macro RAFT agent has been applied to the copolymerization of styrene and butadiene to prepare nanoparticles. First, for the RAFT polymerization of styrene, the results of molecular weights (Mns) and polydispersity index (PDIs) determined by GPC showed that the RAFT mini-emulsion polymerization of styrene exhibited good controlled/living nature with a lower degree of aminolysis (~30%). Second, for the copolymerization of styrene and butadiene, before the gel point the molecular weight growth was followed during the polymerization by GPC and the results revealed that the GPC curve moves to the higher molecular weight indicating the formation of the copolymer. At low conversion, molecular weights (Mns) are in good agreement with theoretical prediction. The microphase separation of the copolymer nanoparticles was confirmed by transmission electron microscopy (TEM). 相似文献
7.
Formulae to calculate the statistically caused instantaneous copolymer composition distribution as well as the chemical distribution of accumulated macromolecules, which is due to polymerization statistics and shifts in mean polymer composition during the reaction process, are derived on the basis of a universal model for free-radical solution polymerization with any number of monomers proceeding in a batch, semi-batch or continuous, ideally mixed vessel. The influence of the reactor type on chemical composition distributions is investigated for a copolymerization of different reactive components (methyl methacrylate/styrene/maleic anhydride), a system with nearly equal reactive monomers (methyl methacrylate/styrene), and the ternary polymerization of methyl methacrylate/styrene/maleic anhydride. Though products of constant mean composition are obtainable in a semi-batch or steady-state continuous reactors, considerable statistical dispersion cannot be removed in any case. 相似文献
8.
Ghanshyam S. Chauhan Lalit K. Guleria B.N. Misra Inderjeet Kaur 《Journal of polymer science. Part A, Polymer chemistry》1999,37(12):1763-1769
A binary mixture of styrene and maleic anhydride has been graft copolymerized onto cellulose extracted from Pinus roxburghii needles. The reaction was initiated with gamma rays in air by the simultaneous irradiation method. Graft copolymerization was studied under optimum conditions of total dose of radiation, amount of water, and molar concentration previously worked out for grafting styrene onto cellulose. Percentage of total conversion (Pg), grafting efficiency (%), percentage of grafting (Pg), and rates of polymerization (Rp), grafting (Rg), and homopolymerization (Rh) have been determined as a function of maleic anhydride concentration. The high degree of kinetic regularity and the linear dependence of the rate of polymerization on maleic anhydride concentration, along with the low and nearly constant rate of homopolymerization suggest that the monomers first form a complexomer which then polymerizes to form grafted chains with an alternating sequence. Grafting parameters and reaction rates achieve maximum values when the molar ratio of styrene to maleic anhydride is 1 : 1. Further evidence for the alternating monomer sequence is obtained from quantitatively evaluating the composition of the grafted chains from the FT‐IR spectra, in which the ratio of anhydride absorbance to aromatic (CC) absorbance for the stretching bands assigned to the grafted monomers remained constant and independent of the feed ratio of maleic anhydride to styrene. Thermal behaviour of the graft copolymers revealed that all graft copolymers exhibit single stage decomposition with characteristic transitions at 161–165°C and 290–300°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1763–1769, 1999 相似文献
9.
采用2,2,6,6-四甲基-1-哌啶氧化物(TEMPO)的溴盐对化学共沉淀法制备的Fe3O4纳米粒子进行表面修饰,以该粒子为过氧引发剂,苯乙烯(St)、马来酸酐(MA)为单体,采用"活性"/可控自由基聚合技术在粒子表面原位引发聚合,制备了聚(苯乙烯-马来酸酐)/Fe3O4纳米杂化材料,并对纳米Fe3O4及杂化材料进行了FT-IR、XRD、TGA、TEM和GPC表征。结果表明,所制备的纳米杂化材料的平均粒径约为70 nm,磁性粒子表面的聚合物分子链随着聚合时间的增长而增长。振动样品磁强计测试结果显示,在室温、外加磁场下,该纳米杂化材料呈现超顺磁性,饱和磁化强度随着包覆聚合物量的增加而降低。 相似文献
10.
Kazuyuki Fukano Eiichi Kageyama 《Journal of polymer science. Part A, Polymer chemistry》1975,13(6):1325-1338
The radiation-induced polymerization of methyl methacrylate (MMA) absorbed on such inorganic substances as silica gel, white carbon, silicic acid anhydride, zeolite, and activated alumina was carried out to compare with the case of styrene. The rate of radiation-induced polymerization adsorbed on inorganic substances was high compared with that of radiation-induced bulk state polymerization, as was the case with styrene. Inorganic substrates which contain aluminum as a component element are more likely to be grafted than those which consist of SiO2 alone, as with styrene. The molecular weight distribution of unextractable polymer and extractable polymer differs, depending on the type of inorganic substance. Experiments by a preirradiation method were carried out in case of silica gel, white carbon, and silicic acid anhydride. GPC spectra of the polymer obtained were different from those of polymer formed by the simultaneous irradiation method. It appears that all the unextractable polymer is grafted to the inorganic surface with chemical bond. 相似文献
11.
The reactivity of copolymer silane composed of maleic anhydride in the modification of fine colloidal silica was studied.
The reaction of colloidal silica of 10 and 45-nm diameter with trimethoxysilyl-terminated poly(maleic anhydride-co-styrene) [P(MA-ST)] and poly(MA-co-methyl methacrylate) in tetrahydrofuran resulted in effective surface modification without particle aggregation. From the
results that the reaction using the polystyrene silane of low molecular weight led to partial aggregation, it was suggested
that the steric interaction between relatively rigid copolymer chains having a maleic anhydride moiety adsorbed on the silica
prevented the aggregation in the reaction. The 29Si cross-polarization magic-angle-spinning NMR spectra of P(MA-ST)-modified silica showed that the polymer silane was bound
to the silica surface by the direct reaction with silica hydroxyl groups and via the polymerization.
Received: 27 June 2001 Accepted: 6 September 2001 相似文献
12.
The crosslinking mechanism and kinetics of low-molecular-weight polybutadiene, its mixtures with maleic anhydride, and the products of its grafting with maleic anhydride and styrene, using dicumyl peroxide (DCP) as an initiator, were studied. It was shown that for all systems crosslinking is a radical polymerization of the double bonds. Modification of polybutadiene changes only the kinetic parameters of the crosslinking reaction and causes mainly a decrease of the termination step velocity. From DSC data the crosslinking reaction order, activation energy, and reaction heats were calculated. 相似文献
13.
For the purpose of the prevention of the environmental pollution and the simplification of reaction process, the scale-up radical graft polymerization of vinyl monomers onto nano-sized silica surface initiated by azo groups and peroxycarbonate groups previously introduced onto the surface in the solvent-free dry-system was investigated. The introduction of azo groups onto the silica surface was achieved by the reaction of surface amino groups with 4,4′-azobis(4-cyanopentanoic acid chloride). On the other hand, the introduction of peroxycarbonate groups onto the silica surface was achieved by Michael addition of surface amino groups to t-butylperoxy-2-methacryloyloxyethylcarbonate. The graft polymerization of vinyl monomers onto the surface was successfully achieved by splaying monomers to nano-sized silica having azo and peroxycarbonate groups in solvent-free dry-system. It is interesting to note that the formation of ungrafted polymer was depressed in comparison with graft polymerization in solution: the grafting efficiency was 90-95%. In addition, in the solvent-free dry-system, the grafting of copolymer having pendant peroxycarbonate groups onto the nano-sized silica surface and the radical postgraft polymerization of styrene initiated by the pendant initiating groups of the grafted copolymer chain on the silica surface was investigated. 相似文献
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Wen Zhou Jian Hua Dong Kun Yun Qiu Yen Wei 《Journal of polymer science. Part A, Polymer chemistry》1998,36(10):1607-1613
Poly(styrene-co-maleic anhydride)/silica hybrid material has been successfully prepared from styrene–maleic anhydride copolymer and tetraethoxysilane (TEOS) in the presence of a coupling agent (3-aminopropyl)triethoxysilane (APTES) by an in situ sol–gel process. It was observed that the gel time of sol–gel solution was dramatically influenced by the amount of APTES. The hybrid material exhibits optical transparency almost as good as both silica gel and the copolymer. The covalent bonds between organic and inorganic phases were introduced by the aminolysis reaction of the amino group with maleic anhydride units of copolymer to form a copolymer bearing trimethoxysilyl groups, which undergo hydrolytic polycondensation with TEOS. The differential scanning calorimetry (DSC) showed that the glass transition temperature of the hybrid materials increases with increasing of SiO2 composition. Photographs of scanning electron microscopy (SEM) and atomic force microscopy (AFM) inferred that the size of the inorganic particles in the hybrid materials was less than 20 nm. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1607–1613, 1998 相似文献
16.
Controlled free radical polymerization (CFRP) of vinyl chloride (VCM) and copolymerization with several comonomers have been studied in aqueous suspension. Therefore di-tert-butylnitroxide and three novel nitroxyl radicals were used as mediating agents. Copolymerization of VCM with styrene, partly combined with acrylonitrile, maleic acid anhydride and maleic acid imide as well as methyl methacrylate, n-butyl methacrylate, butyl acrylate and butadiene have been achieved, demonstrating an efficient route for novel vinyl chloride copolymer architecture. 相似文献
17.
Photoinduced charge transfer polymerization of styrene (St) with electron acceptor asinitiator was investigated. In case of fumaronitrile (FN) or maleic anhydride (MA) asinitiator the polymerization takes place regularly, whereas the tetrachloro-1, 4-benzenequinone (TCQ), 2, 3-dichloro-5, 6-dicyano-1, 4-benzenequinone (DDQ). ortetracyano ethylene (TCNE) as initiator the polymerization proceeds reluctantly only afterthe photoaddition reaction. A mechanism was proposed that free radicals would be formedfollowing the charge and proton transfer in the exciplex formed between St and electronacceptors. 相似文献
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Masoumeh Heydari Peyman Najafi Moghadam Amir Reza Fareghi Morteza Bahram Nasim Movagharnezhad 《先进技术聚合物》2015,26(3):250-254
Synthesis and characterization of polyaniline‐grafted poly(styrene‐alt‐maleic anhydride) (PANI‐g‐PSMA) was carried out to obtain conductive comb copolymers with highly improved processability. First, polyaniline (PANI) was prepared in nano‐scale by chemical synthesis under ultrasonic irradiation. Then the poly(styrene‐alt‐maleic anhydride) (PSMA) was synthesized by free radical polymerization. Moreover, the PANI was grafted on the PSMA backbone to prepare a comb‐like conductive copolymer for improving its processability as a new method. The products were characterized by Fourier transform infrared, ultraviolet–visible spectroscopy and X‐ray diffraction patterns. Morphology of the samples was also investigated by scanning electron microscopy images. Finally, the solubility and conductivity of the products were studied, and it resulted in high solubility of the products in water and other common organic solvents in comparison to the pure PANI. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
20.
将引发剂偶氮二异丁腈(AIBN)、共聚单体苯乙烯(St)和马来酸酐(MA)溶解于甲苯中,采用沉淀聚合法合成苯乙烯-马来酸酐共聚物(SMA).分别研究了反应温度、引发剂用量、反应时间、单体配比和单体浓度对聚合物得率和酸酐含量的影响.采用正交实验确定最优反应条件为:单体浓度20%,单体物质的量比为1∶1,引发剂用量为0.60%,反应温度为86℃,反应时间2h,产物得率为86.86%,酸酐含量为50.28%.并利用傅里叶变换红外光谱(FTIR)、核磁共振碳谱(~(13)C NMR)、凝胶渗透色谱(GPC)和热分析法分别研究聚合物的分子结构、相对分子质量及相对分子质量分布和热稳定性.结果表明产物是苯乙烯-马来酸酐交替共聚物,相对分子质量分布较窄,具有良好的热稳定性. 相似文献