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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
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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
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苯乙烯—马来酸酐自由基共聚反应:(Ⅱ)苯乙烯—马来酸酐聚合反应机理 总被引:4,自引:0,他引:4
简要地综合苯乙烯-马来酸酐共聚反应机理和数学模型研究和进展。在一定程度上络合-解离模型更能说明苯乙烯-马来酸酐共聚过程。 相似文献
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合成了一系列苯乙烯.马来酸酐共聚物(SMA)。并对共聚物的结构进行了表征。用土埋法和CO2释放法研究了共聚物的生物降解性。探讨了分子量、组成、环境等因素对生物降解性的影响,发现共聚物的分子量降低。降解率增大;共聚物中马来酸酐含量提高。降解率增大;适宜的环境有利于生物降解。 相似文献
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电荷转移络合物反应机理是研究苯乙烯-马来酸酐自由基交替共聚反应机理的关键。本文简述了苯乙烯-马来酸酐电荷转移络合物的研究进展。 相似文献
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Eun‐Soo Park Mal‐Nam Kim Ik‐Mo Lee Han Sup Lee Jin‐San Yoon 《Journal of polymer science. Part A, Polymer chemistry》2000,38(12):2239-2244
Styrene/maleic anhydride (MA) copolymerization was carried out using benzoyl peroxide (BPO) and 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO). Styrene/MA copolymerization proceeded faster and yielded higher molecular weight products compared to styrene homopolymerization. When styrene/MA copolymerization was approximated to follow the first‐order kinetics, the apparent activation energy appeared to be lower than that corresponding to styrene homopolymerization. Molecular weight of products from isothermal copolymerization of styrene/MA increased linearly with the conversion. However products from the copolymerization at different temperatures had molecular weight deviating from the linear relationship indicating that the copolymerization did not follow the perfect living polymerization characteristics. During the copolymerization, MA was preferentially consumed by styrene/MA random copolymerization and then polymerization of practically pure styrene continued to produce copolymers with styrene‐co‐MA block and styrene‐rich block. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2239–2244, 2000 相似文献
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Maleic anhydride (MAH) was photografted onto low density polyethylene substrates at temperatures above the melting point of MAH. The effects of some principal factors including irradiation temperature, photoinitiators, the intensity of UV radiation, and the far UV radiation on the grafting polymerization were investigated in detail. Percent conversion and grafting efficiency of the polymerizations were determined by the gravimetric method. The contact angles of the grafted film PE-g-PMAH against water and the FTIR spectrum of the grafted film were measured as characterization. The results show that the photografting polymerization of MAH can proceed smoothly at temperatures higher than the melting point of MAH; the far UV radiation and the intensity of the UV radiation affect the grafting polymerization greatly; the photoinitiators also have influence on the polymerization. According to the FTIR spectra, it is clearly confirmed that the grafted film samples contain anhydride groups. The contact angles demonstrate that the wettability of the grafted films is enhanced obviously, especially to those grafted film samples through hydrolysis. 相似文献
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Hellfried Karpf Oskar E. Polansky Maximilian Zander 《Monatshefte für Chemie / Chemical Monthly》1981,112(5):659-667
The photoDiels-Alder reaction of maleic anhydride with chrysene yields chryseno[4,5-efg]isobenzofuran-4,6-dion (VI). Heavy atom experiments using xenon as an external perturber show that the reaction occurs via the lowest singlet excited state of chrysene. Hydrogen is abstracted from the primaryDiels-Alder adduct IV by the solvent CH2Cl2 possibly in a two-step mechanism. The reaction presents a new type of photoreaction, its mechanism possibly follows a scheme not considered so far in photochemistry.
1,4-Photoaddition von Maleinsäureanhydrid an Chrysen
Zusammenfassung Die Photo-Diels-Alder-Reaktion von Maleinsäureanhydrid mit Chrysen ergibt Chryseno[4,5-efg]-isobenzofuran-4,6-dion (VI). Schweratomexperimente mit Xenon als äußerer Störer zeigen, daß die Reaktion vom niedrigst angeregten Singulettzustand des Chrysens ausgeht. Die Abstraktion von Wasserstoffatomen aus dem primärenDiels-Alder-Addukt IV durch das Lösungsmittel CH2Cl2 folgt möglicherweise einem Zweistufenmechanismus. Die Reaktion stellt einen neuen Typ von Photoreaktion dar; möglicherweise folgt sie einem Mechanismus, der in der Photochemie neuartig ist.相似文献
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Ronghua Zhang Yutian Zhu Jianguo Zhang Wei Jiang Jinghua Yin 《Journal of polymer science. Part A, Polymer chemistry》2005,43(22):5529-5534
A series of 13C‐enriched maleic anhydride grafted isotactic polypropylene samples were prepared in solution at 170 °C by changes in the initial maleic anhydride content. The NMR spectra of the samples showed that the signals of the maleic anhydride attached to the tertiary carbons of the isotactic polypropylene chains increased considerably with increasing maleic anhydride content, whereas the signals of the maleic anhydride on the radical chain ends (with a single bond) arising from β scission did not. On the other hand, the signals of the maleic anhydride on the radical chain ends with double bonds increased markedly with increasing maleic anhydride content, and this suggested that β scission could occur extensively after maleic anhydride was attached to the tertiary carbons. As a result, the molecular weight of the grafted polypropylene decreased significantly with increasing maleic anhydride content in this study. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5529–5534, 2005 相似文献
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S. Ranganathan W. E. Baker K. E. Russell R. A. Whitney 《Journal of polymer science. Part A, Polymer chemistry》1999,37(20):3817-3825
The structural features of the grafting of maleic anhydride onto low-molecular-weight compounds have been elucidated using several spectroscopic and analytical techniques. Conclusive evidence for the occurrence of singly grafted anhydride residues in multiply grafted products has been established using 2,3-13C2 labeled maleic anhydride. In homogeneous solution, at the low concentrations of maleic anhydride employed, there is little evidence for oligomeric or polymeric grafts to dodecane, pristane, or squalane. The results suggest that isothermal grafting of maleic anhydride to hydrocarbon polymers should also lead to a predominance of single grafts. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3817–3825, 1999 相似文献
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L. G. Bruk A. P. Kozlova O. V. Marshakha I. V. Oshanina O. N. Temkin O. L. Kaliya 《Russian Chemical Bulletin》1999,48(10):1875-1881
A classification of polyfunctional catalytic systems based on discrimination of the main component (the catalyst participating
in all stages of the formation of the product of catalytic reaction) and elucidating the functions of additional components
of a catalytic system is suggested. The role of additional components in a number of new palladium-based catalytic systems
used in the synthesis of maleic anhydride by oxidative carbonylation of acetylene was studied. It was established that the
functions of Co and Fe phthalocyanine complexes (PcCo and Pc*Fe, respectively) in the mechanism of the process are different.
Translated fromIzvestia Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1899–1905, October, 1999. 相似文献
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Bo Pan Kalyanaraman Viswanathan Charles E. Hoyle Robert B. Moore 《Journal of polymer science. Part A, Polymer chemistry》2004,42(8):1953-1962
The photoinitiated grafting of maleic anhydride (MAH) onto polypropylene with the use of benzophenone (BP) as the initiator has been investigated. In comparison with the process of thermally initiated grafting with peroxide as the initiator, photoinitiated grafting affords a higher grafting efficiency. The efficient photografting sensitized by BP can be explained by two possible mechanistic processes: the sensitization of the formation of the excited triplet state of MAH by BP and electron transfer followed by proton transfer between MAH and the benzopinacol radical, which may operate together. In the former case, the generated MAH excited triplet state abstracts a hydrogen from the polymer substrate to initiate grafting. A rate constant of 3.6 × 109 M ?1 s ?1 has been determined by laser flash photolysis for the process of quenching the excited triplet state of BP with ground‐state MAH. In comparison, the rate constant for the quenching of the excited triplet state of BP by hydrogen abstraction has been determined to be 4.1 × 105 M ?1 s ?1. In a study of photografting using a model compound, 2,4‐dimethylpentane, as a small‐molecule analogue of polypropylene, the loss of BP was significantly reduced upon the addition of MAH, and this is consistent with the proposed mechanistic processes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1953–1962, 2004 相似文献
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《Physics and Chemistry of Liquids》2012,50(6):551-560
The solution behaviors of the chlorinated polypropylene (CPP) and its grafted polymers (CPP-g-MAH) were systematically studied to characterize their polar change with grafting maleic anhydride (MAH) onto the chain of CPP. The molecular weights of the polymers were determined with light scattering measurements, and the Mark–Houwink equation of CPP in toluene was also obtained. The result showed that the Mark–Houwink equation of CPP was suitable for estimating the molecular weight of the polydisperse samples of CPP and not suitable to CPP-g-MAH because the molecular polarity of the graft polymers had changed with grafting MAH onto CPP. The solubility result of CPP and CPP-g-MAH in various solvents indicated that the polarity of CPP gradually increased with grafting MAH onto its chain, which would cause the solubility of poorly hydrogen bonded solvents for CPP-g-MAH to gradually become poor, whereas that of moderately hydrogen bonded solvents for the polymers becomes better with an increase of the MAH graft content. This is consistent with the results of their dilution ratio and solubility parameter. Stabilities of the 344# resin–CPP-g-MAH–toluene solutions showed that the miscibility of CPP-g-MAH and 344# resin was improved with increase of the MAH grafted content. 相似文献
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R. K. Sadhir J. D. B. Smith 《Journal of polymer science. Part A, Polymer chemistry》1992,30(4):589-595
This article describes the laser-initiated copolymerization of N-vinylpyrrolidone with maleic anhydride and maleimide via charge transfer complexes. The dependence of copolymer yield on the molar ratios of the monomers in the feed and on the irradiation time is described. Based on the ultraviolet and infrared spectroscopy, and chemical analysis results, a tentative mechanism of polymerization is suggested. The rates of polymerization of several monomer systems are compared. The N-vinylpyrrolidone and maleimide system shows the highest rate of polymerization. 相似文献
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A preliminary study of using maleic anhydride copolymer for protein binding has been carried out.The polymeric films were prepared by compression of the purified resin and annealing the film to induce efficient back formation of the anhydride groups.The properties of the film surface were analyzed by attenuated total reflection Fourier transforms infrared spectroscopy and water contact angle measurements.The protein content was determined by Bradford assay.To obtain optimum conditions,immersion time for protein binding was examined.Results revealed that proteins can be successfully immobilized onto the film surface via covalent linkage.The efficiency of the covalent binding of the extractable protein to maleic anhydride-polyethylene film was estimated at 69.87μg/cm~2,although the film had low anhydride content(3%) on the surface. 相似文献