Fe-Al络合催化苯乙烯-马来酸酐交替共聚

应用Ｆｅ（ａｃａｃ）３ Ａｌ（ｉ Ｂｕ）３（ａｃａｃ＝乙酰丙酮）催化苯乙烯 马来酸酐共聚,制得富于交替的白色粉末共聚物．共聚反应动力学研究表明,共聚反应与单体浓度呈一级关系,表观活化能为４８６ｋＪ／ｍｏｌ．     

Alternating copolymerization of benzofuran and acrylic monomers in the presence of organoaluminum compounds

The copolymerization of benzofuran and acrylic monomers, such as acrylonitrile, methacrylonitrile, methyl acrylate, and methyl methacrylate, was investigated in the presence of aluminum compounds as complexing agents for acrylic monomers. Among the various kinds of aluminum compound, ethylaluminum sesquichloride is the most suitable for alternating copolymerization, whereas ethoxyaluminum compounds of low acidity allow the incorporation of excess acrylic monomer and dichloride of strong acidity is likely to induce cationic homopolymerization of benzofuran as a side reaction. The equimolar amount of sesquichloride with respect to acrylic monomer is necessary for alternating copolymerization. Azobisisobutylonitrile (AIBN) is an effective initiator but benzoyl peroxide is not. Nuclear magnetic resonance (NMR) of the copolymer indicates that the copolymer is essentially alternating, although some block sequences of acrylic monomer sometimes exist. As a mechanism the copolymerization via a ternary complex of acrylic monomer, aluminum compound, and benzofuran is considered. Free acrylic monomer participates in copolymerization when the amount or acidity of the complexing agent is insufficient. A quantitative relation between monomer and copolymer composition is derived from a scheme based on the copolymerization of the donor monomer-acceptor monomer complex with free acrylic monomer.     

4-丙烯酸-2,2,6,6-四甲基哌啶醇酯自由基共聚合的研究(Ⅰ)

本文从单体浓度、共聚单体配比、引发体系、温度等条件对带有易生成稳定自由基的4-甲基丙烯酸-2,2,6,6-四甲基哌啶醇酯与苯乙烯的自由基共聚合行为进行了探讨。发现在一般情况下符合自由基聚合规律。在不长的时间内可得到高产率(80％以上),较高分子量(～10~4)的白色粉末状共聚物。哌啶环上的亚胺基未表现出明显的阻聚作用。另外,用IR、NMR、VPO、元素分析等方法对共聚物的结构与性能进行了表征。此共聚物在多种普通有机溶剂中可溶,热稳定性能良好,毒性试验证明基本无毒。     

Donor-Acceptor Complexes in Copolymerization. LIX. Alternating Diene-Dienophile Copolymers. 13. Copolymerization of Dicyclopentadiene and Maleic Anhydride

The solution and bulk copolymerization of dicyclopentadiene (DCP) and maleic anhydride (MAH) occurs over the temperature range 80–240°C, upon the addition of a free-radical catalyst which has a short half-life at the reaction temperature. An unsaturated 1/1 MAH/DCP copolymer, derived from the copolymerization of MAH with the norbornene double bond, followed by a Wagner-Meerwein rearrangement, is obtained in the presence of a large excess of DCP at 80° C, while a saturated 2/1 MAH/ DCP copolymer, derived from the cyclocopolymerization of the residual cyclopentene unsaturation, is obtained at higher temperatures or in the presence of excess MAH. The copolymers prepared under other conditions with intermediate MAH/DCP mole ratios contain both 1/1 and 2/1 repeating units. The copolymer obtained from bulk copolymerization above 170° C contains units derived from cyclopentadiene-MAH cyclocopolymerization as well as DCP-MAH copolymerization.     

耐热性星形甲基丙烯酸甲酯共聚物的合成

195 6年 ,Swarzc等 [1,2 ] 报道了一种没有链转移和链终止的阴离子聚合技术 ,提出了“活性”聚合的概念 . 1 995年王锦山等 [3]发现和提出原子转移自由基聚合 ( ATRP)以来 ,活性自由基聚合就成了高分子合成领域的研究热点 ,并合成出各类指定结构的聚合物 [4～ 12 ] .具有环状结构的 N -环己基马来酰亚胺 ( NCMI)被广泛地用于与甲基丙烯酸甲酯 ( MMA)自由基共聚合制备耐热性有机透明材料 [13,14 ] ,但NCMI的引入将降低聚合物的加工流动性 ,若能利用多官能团引发剂如四溴甲基苯实现含 NCMI单体结构的可控 ATRP共聚合 ,合成出星形耐…     

壳多糖与丙烯酸丁酯的乳液接枝共聚研究

以十二烷基苯磺酸钠为乳化剂，过硫酸钾－亚硫酸氢钠为引发剂，研究了壳多糖与丙烯酸丁醋的乳液共聚合，结果表明当［Ｋ２Ｓ２Ｏ８］＝［ＮａＨＳＯ３］＝２．５７×１０－３ｍｏｌ·１－１，［ＢＡ］＝０．６８ｍｏｌ．１－１，［Ｃｈｉｔｏｓａｎ］＝１９．２ｇ·ｌ－１，在７０℃下反应５小时，共聚反应的接技率和接枝效率均较高．用红外光谱，差热分析，Ｘ射线衍射，扫描电镜对接技共聚物进行了表征，此外测试了共聚物胶乳成膜的机械性能，表明用丙烯酸丁酯对壳多糖进行接枝改性，可提高壳多糖的韧性，扩大其应用范围．     

Alternative copolymerization of aziridines and carbon monoxide by γ-ray irradiation

The copolymerization of carbon monoxide and aziridines such as ethylenimine and propylenimine was carried out by γ-ray irradiation. Aziridines and carbon monoxide were allowed to copolymerize under γ-ray irradiation from a Co⁶⁰ source and gave a crystalline solid copolymer. The yield of the copolymer increased with reaction temperature. The composition of copolymers obtained did not depend on the feed ratio of monomers and was found to be almost equimolar. The copolymer of ethylenimine and carbon monoxide melted at about 322–335°C. with decomposition and has an infrared spectrum identical with that of poly-β-alanine obtained by the hydrogen-migration polymerization of acrylamide. The hydrolyzed product of the ethylenimine–carbon monoxide copolymer was confirmed to be β-alanine by paper chromatography. These results lead to the conclusion that the copolymerization of aziridines and carbon monoxide took place alternatively by γ-ray irradiation, and produced crystalline poly-β-alanines.     

Nd(naph)3-Al(i-Bu)3催化邻苯二甲酸酐与环氧丙烷交替共聚

Ｎｄ（ｎａｐｈ）３Ａｌ（ｉＢｕ）３催化邻苯二甲酸酐与环氧丙烷交替共聚房江华黄士力（宁波师范学院化学系，宁波３１５０２０）沈之荃（浙江大学高分子科学与工程学系，杭州３１００２７）关键词环烷酸钕，交替共聚，邻苯二甲酸酐，环氧丙烷分类号Ｏ６４３／ＴＱ３...     

(2-甲基丙烯酰氧乙基)三甲基氯化铵-丙烯酰胺双水相共聚合

将(2-甲基丙烯酰氧乙基)三甲基氯化铵(DMMC)与丙烯酰胺(AM)在聚乙二醇(PEG)水溶液中进行双水相共聚合(ATPC),并与DMMC/AM均相水溶液共聚合(HASC)进行比较.在均相水溶液共聚合体系中得到了DMMC/AM共聚体系的竞聚率分别为rDMMC=1.77、rAM=0.32,并给出了竞聚率的95%,99%联合置信区域.比较了两种共聚合体系的转化率-时间曲线和共聚组成,表明双水相共聚合体系初期反应速率高于均相水溶液共聚合体系,但最终转化率相似;两种共聚合体系得到的共聚物组成有较大差别.测得了DMMC、AM以及DMMC-AM共聚物(CPAM)在65℃、反应条件下的相分配系数为K1=0.035、K2=0.125和Kp=0.011.结合双水相聚合的本质以及单体和共聚物在两相的分配系数,提出了一个计算双水相共聚组成的新方法,用该方法计算的双水相共聚合体系的共聚组成与实验点吻合较好.     

Radical copolymerization of N‐phenylmaleimide and diene monomers in competition with diels–alder reaction

Radical copolymerization of N‐phenylmaleimide (PhMI) is carried out with various diene monomers including naturally occurring compounds and the copolymers are efficiently produced by the suppression of Diels–Alder reaction as the competitive side reaction. Diene monomers with an exomethylene moiety and a fixed s‐trans diene structure, such as 3‐methylenecyclopentene and 4‐isopropyl‐1‐methyl‐3‐methylenecyclohexene, exhibit high copolymerization reactivity to produce a high‐molecular‐weight copolymer in a high yield. The copolymerization of sterically hindered noncyclic diene monomers, such as 2,4‐dimethyl‐1,3‐pentadiene and 2,4‐hexadiene, also results in the formation of a high‐molecular‐weight copolymer in a moderate yield. The NMR spectroscopy reveals that the obtained copolymers consist of predominant 1,4‐repeating structures for the corresponding diene unit. The copolymers have excellent thermal stability, that is, an onset temperature of decomposition over 330 °C and a glass transition temperature over 130 °C. The copolymerization reactivity of these diene monomers is discussed based on the results of the DFT calculations. The efficient copolymer formation in competition with Diels–Alder addition is investigated under various conditions of the temperature, solvents, and initiators used for the copolymerization. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3616–3625.     

Specific phenomena during the copolymerization of trioxane and ethylene oxide

We, at Asahi Chemical in Japan, have industrialized three types of polyacetal resins, that is, the acetal homopolymer, copolymer and block copolymer using anionic, cationic and anionic polymerization techniques, respectively. During this industrialization, we observed various phenomena, which were not previously reported. First, the authors outline the three technologies for producing each type of polyoxymethylene from an industrial viewpoint. Next, the authors discuss a newly found reaction during the induction period of the trioxane and ethylene oxide copolymerization. Experimental proof of direct ring expansion between the reaction of trioxane and ethylene oxide is discussed and various novel cyclic compounds are also shown. To the best of our knowledge, this reaction may be the world's first experimental proof of direct ring expansion of the reaction of a cyclic monomer. Third, the authors also discuss the newly founded morphospecific polymer from the copolymerization of trioxane and ethylene oxide using boron trifluoride dibutyl ether as an initiator.     

微波辅助壳聚糖接枝聚乳酸共聚物的合成及表征

在微波辅助下,以辛酸亚锡为催化剂、壳聚糖(CS)为大分子引发剂引发消旋丙交酯（D,L-LA）本体开环聚合制备了壳聚糖接枝聚乳酸共聚物。通过正交实验研究了微波功率、催化剂用量、反应温度和反应时间对聚合反应的影响,确定了最佳合成条件。并通过红外光谱、元素分析、核磁共振氢谱、X-射线衍射和热分析对接枝共聚物的结构与性能进行了表征。结果表明,在微波条件下,能快速、有效地合成预定结构的壳聚糖接枝聚乳酸共聚物;聚乳酸支链的引入,有效削弱了壳聚糖分子间和分子内较强的氢键作用,与相应的壳聚糖比较,共聚物的结晶性能下降,热分解温度降低;原料配比对共聚物的结构与性能有显著影响,随nD,L-LA/nCS糖环数值增大,共聚物中平均乳酰单元数逐渐增大,共聚物的结晶性能、起始分解温度逐渐下降。     

Propagation Mechanism of Radical Copolymerization of Sulfur Dioxide and Vinyl Chloride

Radical copolymerization of sulfur dioxide and vinyl chloride (VC) has been studied by the comparison of the composition of copolymers obtaining from different reaction conditions, i.e., reaction temperatures, feed compositions, and total monomer concentrations. The composition of VC in copolymer is independent of comonomer composition except at high concentration of VC in feed; it increases with increasing reaction temperature or decreasing total monomer concentration. At lower temperature, the composition of copolymer becomes independent of total monomer concentration. The overall rate of polymerization is proportional to [VC]^1,7 and [SO₂]^0.5. These results were compared with those obtained in our previous study on the SO₂-styrene copolymerization. A propagation mechanism for radical copolymerization of SO₂ and VC is also proposed.     

Stabilizer‐free dispersion copolymerization of maleic anhydride and vinyl acetate. I. Effects of principal factors on microspheres

A novel dispersion copolymerization of maleic anhydride (MAn) and vinyl acetate (VAc) without adding stabilizer is developed, which gives uniform copolymer microspheres with tunable sizes. Some principal factors affecting the microspheres, such as reaction time, monomer concentration and feed ratio, reaction media, and cosolvent, were investigated. It was found that the stabilizer‐free dispersion copolymerization of MAn and VAc is a rapid process, and the particle size grows in accordance with the evolution of polymerization. The chemical composition of the copolymer microspheres was characterized by FT‐IR and ¹³C NMR spectroscopies. Over a wide range of monomer concentrations, the microspheres can always be formed and stably dispersed, with uniform sizes ranging from 180 nm to 740 nm. The yield of copolymer microspheres reaches a maximum at 1:1 feed ratio of MAn to VAc, owing to the alternating copolymerization between the binary monomers by a known charge‐transfer‐complex mechanism. However, the diameter of microspheres drastically increases when MAn content is enhanced. Only some specific alkyl ester solvents, such as n‐butyl acetate, isobutyl acetate, n‐amyl acetate, are desirably fit for this unique stabilizer‐free dispersion polymerization. Furthermore, we found that when some acetone is added as a cosolvent, the copolymer microspheres can still be formed, with much larger diameters. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3760–3770, 2005     

载体型钛系催化剂的丙烯与乙烯共聚合研究

以载体型钛系齐格勒-纳塔催化剂进行了丙烯和乙烯无规共聚合的研究。对聚合温度、铝钛摩尔比、给电子体浓度和加氢等行为作了考察。共聚合速度和共聚物的比浓粘度呈规律性变化。用~(13)C-NMR和DSC测定了共聚物的组成、序列分布、熔点和结晶度.结果表明,在共聚合反应速度曲线上,在丙烯和乙烯分别为10mol％组成处,出现两个最大值。随共聚物中乙烯含量增加(2—10mol％),其熔点和结晶度降低,DSC峰变低、变宽,在乙烯含量达10mol％处出现双峰(128/116℃)反映出无规共聚链出现不同的序列分布。     

Mechanism of graft copolymerization of styrene onto deproteinized natural rubber

High conversion and high grafting efficiency attained by graft copolymerization of styrene onto deproteinized natural rubber (DPNR) was investigated with respect to the molecular weight of grafted polystyrene. The graft copolymerization was performed with tert-butyl hydroperoxide/tetraethylenepentamine as an initiator after deproteinization of natural rubber with urea. Grafted polystyrene was isolated from the resulting graft copolymer by ozonolysis reaction. After the ozonolysis of the graft copolymer of DPNR and polystyrene (DPNR-g-PS), the molecular weight of grafted polystyrene was determined by size exclusion chromatography. Effects of initiator and monomer concentrations were investigated with respect to the molecular weight of the grafted polystyrene, which was found to depend on not only the number of active site generated on the rubber particle but also the feed of styrene. Deactivation and chain transfer of the active sites were attributed to effective amount of styrene used for the graft copolymerization.     

Monomer reactivity ratios in graft copolymerization

This paper discusses monomer reactivity ratios in various radiation- and redox-initiated graft copolymerizations. The polymers studied were polyethylene, cellulose acetate, poly(vinyl chloride), polytetrafluoroethylene, poly(vinyl alcohol), and poly(methyl methacrylate); the comonomer mixtures were styrene–acrylonitrile, methyl acrylate–styrene, acrylonitrile–methyl acrylate, and vinyl acetate–acrylonitrile. The polymer–comonomer mixture systems were so chosen as to permit study of both homogeneous and heterogeneous systems. The homogeneous systems included systems of low and high viscosity. The heterogeneous systems included both polymers swollen by the comonomer mixture and polymers not swollen by the comonomer mixture. None of the homogeneous grafting systems studied showed deviations from the normal copolymerization behavior under a variety of experimental conditions. Monomer reactivity ratios in graft copolymerization were the same as the values in nongraft copolymerization. The heterogeneous systems in which the polymer was swollen by the comonomer mixture yielded grafted copolymer compositions which were the same as those in nongraft copolymerization. The heterogeneous grafting system polytetrafluoroethylene/styrene–acrylonitrile showed deviations from normal copolymerization behavior at low degrees of grafting when the reaction was only on the polymer surface. The behavior became normal at higher degrees of grafting when the system approaches that in which the polymer is swollen by the comonomers. In all reaction systems, it was found that the use of radiation to initiate the reaction does not in any way affect the copolymerization behavior of the two monomers in a comonomer pair.     

氯化原位接枝反应制备羟基官能化CPE——结构表征

以高密度聚乙烯(HDPE)为基体,采用气-固氯化原位接枝反应合成了以氯化聚乙烯(CPE)为骨架聚合物、丙烯酸-2羟基乙酯(HEA)为支链的接枝共聚物.反应中不需要加入任何引发剂,以氯自由基引发接枝及氯代反应,得到羟基官能化CPE接枝聚合物.并用1H-NMR,FT-IR,GPC及X-射线衍射等对接枝共聚物的结构进行了表征.     

SalenAl(OiPr)催化CO2与氧化环己烯共聚及影响因素研究

以SalenAl(OiPr)为催化剂,分别加入各种路易斯碱作为共催化剂催化二氧化碳与氧化环己烯共聚,发现共聚催化效率与共催化剂的供电子能力有关.分别研究催化剂浓度、共催化剂的用量、反应时间、反应温度、CO2压力等各种因素对该共聚反应的影响,发现SalenAl(OiPr)浓度为2 g/L时,以等摩尔量的二甲氨基吡啶(DMAP)作为共催化剂,在4 MPa的CO2和80℃下反应32 h,可得到碳酸酯键含量>99%的共聚产物,其催化效率高达495 g/g,13C-NMR检测表明共聚物为无规立构聚合物,GPC测得分子量Mn为55900,分子量分布比较窄(PDI=1.32).DSC得到共聚物的玻璃化转变温度为136℃,热重分析(TGA)可以看出共聚物在350℃可完全分解,具有优良的热分解性.