Studies on the Self-condensing Vinyl Polymerization of a Novel Maleimide Inimer

The self-condensing vinyl polymerization(SCVP) of a novel maleimide inimer(initiator-monomer) 1, N-(4-α-bromobutyryloxy phenyl) maleimide with the complex of CuBr/Bipy(2, 2′-bipyridine) as the catalyst was studied. GPC was used to determine the molecular weight and the results show that the molecular weight increases exponentially with polymerization time during the first hour, and then the rate of increase molecular weight slows down. The molecular weight also increases with increasing dosage of the catalyst. The coincidence of the molecular weights determined by 1H NMR and GPC proves that the polymer obtained from the SCVP of inimer 1 has a linear structure, which is further verified by 13C NMR spectrum. A hyperbranched polymer was obtained by the copolymerization of inimer 1 and styrene.

Studies on the Self-condensing Vinyl Living Radical Polymerization of a Novel Acrylate Inimer

A novel acrylate inimer, 2-（2-chloroacetyloxy） ethyl acrylate, was prepared by the reaction of 2-hydroxyethyl acrylate with chloroacetyl chloride in the presence of triethylamine. The self-condensing vinyl living radical polymerization of the inimer was studied and the hyperbranched macromolecules containing ester linkages on their backbone were prepared. All the polymerization products were characterized by 1H NMR. The polymerization degree and the branching parameter were calculated based on the 1H NMR spectra. It has been shown that this inimer exhibits a very distinctive polymerization behavior. Similar to step-growth polymerization, the polymerization degree of the products formed increased exponentially during the early stage of the polymerization, and then the increasing rate slowed down. However, the inimer remained present throughout the polymerization consistent with conventional free radical polymerization. Also, if much longer polymerization time was used, the polymerization system would become gel due to the crosslinking reaction derived from radical-radical recombination. As a result of the unequal reactivity of -CH2Cl and >CHCl, an almost linear product was obtained at a molar ratio of bipy to inimer=0.05, while a relatively high ratio of bipy to inimer 1 favored the formation of the branched structure. The macromolecules formed at a high ratio of bipy to inimer 1 exhibited an excellent solubility in organic solvents such as acetone.

Nutrient Release Characteristics of Vinyl Chloride-Vinyl acetate Copolymers Coated SlowRelease Nitrogen Fertilizer and Its Effect on Soil Mineral Nitrogen

[Objective] The aim was to explore release characteristics of vinyl chlo- ride-vinyl acetate copolymer controlled-release N fertilizer and the effects on minerat nitrogen in soils. [Method] Vinyl chloride-vinyl acetate copolymer and hydroxyl-modi- fied VCNAc were taken as coating materials to prepare slow release fertilizer. Nutri- ent release characteristics of VC/VAc slow release fertilizer was evaluated by water immersion method and the effects of VC/VAc slow release fertilizer on mineral ni- trogen were researched by pot experiment. [Result] The release periods of VC-VAc controlled-release urea and hydroxyl-modified VC/VAc coated urea were 60 and 50 d, respectively. Furthermore, the content of ammonium nitrogen reached the peak on the 30th d and the content of nitrate nitrogen reached the peak on the 60th d in soils in treatments with VCNAc and hydroxyl-modified VC/VAc; the content of nitrate nitrogen rose again on the 120th d in the treatment with VC/VAc. In terms of wheat yield, different treatments showed insignificant differences and rice yield in the treatment with VCNAc was significantly higher than that in the treatment with hy- droxyl-modified VCNAc （P〈0.05）. [Conclusion] The release days of slow controlled- release fertilizer vary upon pot experiment method and water immersion method. Slow controlled-release fertilizer is not suitable for monoculture, due to long fertilizer efficiency, but multiple cropping would be optimal for its role to be fully exploited.

Sound Absorption Properties of Discarded Feathers/Ethylene Vinyl Acetate Copolymer Thermoplastic Composite Materials

The discarded feathers / ethylene vinyl acetate copolymer( EVA) thermoplastic composite materials was obtained with discarded feathers as reinforced material and EVA powders as matrix material by hot pressing method. Sound absorption properties were studied by changing mass ratio of discarded feathers and EVA,thickness of composite materials,hot pressing pressure and hot pressing temperature. It was found that the sound absorption properties of composite materials were good when the mass ratio of discarded feathers and EVA was 1: 1,thickness of composite materials was 30 mm,hot pressing pressure was 8 MPa,and hot pressing temperature was 80 ℃. Under the optimum conditions,the effect of composite density on sound absorption property was analyzed. In a certain range,the sound absorption property was enhanced with the decrease of the composite density.When the composite density was 0. 1g /cm^3, the maximum absorption coefficient was 0.96. Finally,the capillary theory was used to calculate the maximum sound absorption coefficient of discarded feathers / EVA thermoplastic composite materials. The good agreements of experimental results and calculated results proved the validity of the theoretical models.

Photoluminescence and Electroluminescence of the Blue Emission of Devices Based on Poly (p-Phenylenevinylene) Copolymers

Bright blue polymer light-emitting diodes have been fabricated by using the poly(pphenylenevinylene)-based copolymers with 10 C long aliphatic chains as the electroluminescent layers,PBD in PMMA and Alq_(3) as the electron-transporting layers,and aluminum as the cathode.The multilayer structure devices show 190cd/m^(2) light-emitting brightness at 460nm,15 V turn-on vol-tage.It is found that the intensities of photoluminescence and electroluminescence(EL)increase with increasing aliphatic chain length,the EL intensity and operation stability of these polymer light-emitting diodes can be improved by reasonable design of the structure.

Synthesis of Highly Branched Poly(ε-caprolactone) by Self-condensing Atom Transfer Radical Polymerization of Macroinimers

Branched poly（ε-capmlactone） was synthesized by self-condensing atom transfer radical polymerization of macroinimer, α-acryloyoxy-ω-2-bromopropionyloxy poly（ε-caprolactone）, which was prepared by enzyme-catalyzed ring-opening polymerization of ε-caprolactone with 2-hydroxylethyl acrylate as initiator and esterification of the ω-hydroxyl group of the obtained poly（ε-caprolactone） by 2-bromopropionyl bromide.

Removal of manganese from waste water by complexation-ultrafiltration using copolymer of maleic acid and acrylic acid

Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.

SYNTHETIC STUDIES ON BLOOD COMPATIBLE BIOMATERIALSⅡ. SYNTHESIS OF POLY(ETHYLENEGLYCOL MONOMETHYLLTHER ) METHACRYLATE AND ANTITHROMBOGENICITY OF ITS COPOLYMERS

Poly （ethyleneglycol monomethylether） methacrylate （PEGMM）was synthesized by means of the reaction of methacrylyl chloride with sodium monomethylpolyethyleneglycoxide and was characterized by FTIR,;H-NMR,and ultraviolet spectrometries. A series of poly （vinyl alcohol）-graft-PEGMM （PVA-g-PEGMM ）and methyl methacrylate-PEGMM copolymer （PMMA-PEGMM） were prepared and tested for antithrombogenicity in vitro. The results indicate that the antithrombogenicity of the copolymers basically increases with the increasing of the DP of polyoxyethylene （POE） chain and tends to a plateau after the DP around 114,i.e. the long chain structure of POE is favourable to the antithrombogenicityof its copolymers ;moreover, the extent of the improvement ofantithrombogenicity also relates to the PEGMM content of the copolymers and the kind of the matrix that the POE chains are located on. These results are consistent with the anticipation of the hypothesis of maintaining proteins normal conformations for blood compatible bioraaterials.

乙烯与乙烯基三乙氧基硅烷共聚物的制备与表征

采用一系列结构不同的α-二亚胺镍催化剂,在倍半乙基氯化铝(EASC)作用下,以配位共聚的方法制备乙烯和乙烯基三乙氧基硅烷(VTEoS)共聚物。研究了VTEoS的浓度、催化剂用量、n(Al)/n(Ni)、乙烯压力、聚合时间、溶剂以及催化剂结构对共聚反应的影响,得到了最优化的聚合条件。通过核磁共振(NMR)、哀减全反射傅里叶变换红外光谱(ATR-FTIR)、热失重分析(TGA)、焙烧法、聚合物膜的接触角测试等方法分别表征了聚合物的结构、热稳定性、硅质量分数和聚合物膜的表面性能。结果表明,以C4为催化剂,二氯甲烷为溶剂时,共聚活性(以1 mol Ni计)最高达9.10×10^(5) g/(mol·h),共聚物中硅的质量分数为0.74%~3.39%。含硅单体的引入,能够提高聚合物的热稳定性和疏水性能。

N⁃苯基马来酰亚胺共聚物的合成及对PVC树脂耐热改性效果研究

通过种子乳液聚合结合半连续加料方式,成功聚合出分子结构一致且与聚氯乙烯(PVC)树脂具有良好相容性的聚(N‐苯基马来酰亚胺‐苯乙烯‐丙烯腈)(PNSA)共聚物胶乳,将其与PVC树脂直接复合制备PNSA/PVC复合材料,并对PNAS耐热改性的效果进行评价。结果表明,PNSA纳米胶乳颗粒粒径在155.3~251.5 nm之间,粒径分布均一;PNSA共聚物分子组成呈无规结构,分子结构一致,差示扫描量热曲线呈现单一的玻璃化转变温度(T_(g)),且与PVC树脂具有极佳的相容性;PNSA含量由0升高至50%(质量比,下同)时,复合材料的T_(g)由84.8℃提高到107.2℃,提高了22.4℃,维卡软化温度由71.2℃提高到91.9℃,提高了20.7℃;除耐热性改善以外,复合材料的力学性能也有一定程度的提高,本文的研究有利于PVC应用领域的进一步拓展。

Kinetic theory of self-condensing vinyl polymerization

This review introduces the kinetic theory of self-condensing vinyl polymerization (SCVP),including the SCVP of AB inimers,the SCVP with non-equal reactivity between A and B groups,the SCVP in the presence of a small amount of multifunctional initiators,also the SCVP of both inimers and comonomers.The analytical expressions of various molecular parameters for the resulting hyperbranched polymers,such as the molecular size distribution function,the average molecular weight,the polydispersity index and the degree of branching,are reviewed systematically.

Statistical and thermodynamic properties of binary self-condensing vinyl polymerization

The thermodynamic properties of a binary self-condensing vinyl polymerization system consisting of monomers and inimers are investigated by the principle of statistical mechanics.In detail,in terms of two types of canonical partition functions constructed from different viewpoints,the equilibrium free energy,the law of mass action and the size distribution of hyperbranched polymers are obtained.As an application,the specific heat,equation of state and isothermal compressibility concerning the polymerization are given as well.To study the dimension of hyperbranched polymers in the system,a recursion formula satisfied by the(k+1)-th and k-th mean square radius of gyration is derived,and then the first,second and third radius of gyration under different solvent conditions are presented.The influences of the fraction of inimers,the conversion of vinyl groups and the solvent effect on the average dimension of hyperbranched polymers are discussed.

Hybrid copolymerization of cyclic and vinyl monomers

In this work, we report the hybrid copolymerization of various cyclic monomers and vinyl monomers. Our studies demonstrate that 1-tert-butyl-4,4,4-tris-（dimethylamino）-2,2-bis[tris（dimethylamino） phophoranyliden-amino]-2A5,A5-catenadi（phosphazene） （t-BuP4） can catalyze the hybrid copolymerization of caprolactone （CL）, lactide （LA） or cyclic carbonate ester with acrylate or methyl acrylate. However, the polymerization of cyclosiloxane with vinyl monomers yields two corresponding homopolymers, and the polymerization of lactone with acrylonitrile （AN） produces only polyacrylonitrile. Clearly, the extent of matching of activity between a monomer and an active center determines whether or not there is hybrid copolymerization.

A SYNTHETIC APPROACH FOR WATER SOLUBLE HYPERBRANCHED POLY(N,N-ETHYLIDENEBIS(N-2-CHLOROACETYL ACRYLAMIDE)) WITH HIGH DEGREE OF BRANCHING VIA ATOM TRANSFER RADICAL POLYMERIZATION/SELF-CONDENSING VINYL POLYMERIZATION

A novel acrylamide A2B2＊ （A = alkene, B＊ = alkyl chlorine） type inimer was obtained from commercially available 1,2-ethylenediamine, chloroacetyl chloride and acryloyl chloride. The as-prepared monomer can form water-soluble hyperbranched poly（N,N-ethylidene bis（N-2-chloroacetyl acrylamide））s （HPECA） through atom transfer radical polymerization/self-condensing vinyl polymerization method in the presence alkyl chlorine/CuCl/2,2-bipyridine activation system which can effectively suppress the gelation formation.1H-NMR spectra and dual detector size exclusion chromatography proved the hyperbranched structure indisputably, and the degree of branching was determined by the detailed analyses of 1H-NMR spectra. The trend of the degree of branching was in consistent with the result of Mark- Houwink exponent a. The experiment results suggested that the conversion was 67%, Mw = 13.2 x 104, Mark-Houwink a = 0.282 and the degree of branching = 64% when the reaction temperature was 120 ℃, reaction time = 168 h and N,N- ethylidene bis（N-2-chloroacetyl acrylamide）：Cu（I） = 50：0.62.

PVC合成树脂技术及性能改进研究进展

聚氯乙烯(PVC)合成化学的进展主要聚焦于内增塑和减少分子链缺陷结构。对于前者,方法包括:利用PVC分子链中C—Cl键的亲核取代反应及后续的点击反应等引入小分子增塑官能团;利用活性C—Cl键的接枝聚合引入大分子接枝链;自由基共聚合引入自增塑功能单体,如氯乙烯与(甲基)丙烯酸酯聚乙二醇单甲醚酯的共聚物展现出了优异的内增塑性能;可控自由基聚合合成嵌段聚合物等。这些方法虽然制备了不同玻璃化转变温度(T g)的PVC共聚物,但反应物的高成本和工艺过程的复杂性,在工业生产中的应用还存在挑战。在工业生产技术方面,讨论了影响PVC树脂颗粒特性的工艺因素,重点介绍了连续引发剂加入(CiD)技术。CiD技术可以将PVC的聚合反应时间缩短到240min,同时通过降低叔氯的含量而显著提高PVC产品的热稳定性。作为平衡氯碱工业氯气的主要产品,PVC树脂在较长的一段时间是不可替代的,提升生产技术和改进产品质量,开发新的PVC共聚树脂是行业可持续发展的关键。

异丁基乙烯基醚-马来酸酐共聚物化工合成及表征分析研究

为研究异丁基乙烯基醚-马来酸酐共聚物的相关特性,采用溶液自由基共聚合方法,实验合成了异丁基乙烯基醚与马来酸酐交替共聚物。对比研究了反应时间、溶剂比、加料方式、溶剂种类和聚合温度等因素对共聚产品收率及产品特性黏度的影响。将马来酸酐和异丁基乙烯基醚混和物溶解在乙酸乙烯酯中,滴加入57℃下的环己烷中,合成得到异丁基乙烯基醚和马来酸酐的交替共聚物,产率在90%以上。

A Unified Theoretical Treatment on Statistical Properties of the Semi-batch Self-condensing Vinyl Polymerization System

We present a novel generating function(GF)method for the self-condensing vinyl polymerization(SCVP)system with any initial distribution of preexisted polymers.Such a method was proven to be especially useful to investigate the semi-batch SCVP system allowing a sequence of feeding operations during the polymerization.Consequently,the number-,weight-,and z-average molecular weights as well as dispersity index of hyperbranched polymers can be explicitly given,which are determined by predetermined feeding details and conversions in each polymerization step.These analytical results are further confirmed by the corresponding Monte Carlo simulations.Therefore,the present GF method has provided a unified treatment to the semi-batch SCVP system.Accordingly,hyperbranched polymers with desired properties can be prepared by designing feeding details and presetting conversions at each step based on the present GF method.

Conventional Radical and RAFT Alternating Copolymerizations of Hydroxyalkyl Vinyl Ethers and Dialkyl Maleates

The alternating copolymerization of hydroxyalkyl vinyl ethers and dialkyl maleates is investigated by conventional radical polymerization and reversible addition-fragmentation chain transfer polymerization(RAFT).The influence of comonomer structure,comonomer feeding ratios,and monomer concentrations on the copolymerization and the copolymer structure have been investigated systematically.With 2-hydroxyethyl vinyl ether(HEVE)and dimethyl maleates(DMM)as comonomers,a well-defined alternating copolymer is prepared with M_(n)=3400 and M_(w)/M_(n)=1.93 up to 71.6% monomer.The alternating sequential chain structure of the copolymers has been proved by both NMR and matrixassisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS).The experimental reactivity ratios and theoretical calculated highest occupied molecular orbital and the lowest unoccupied molecular orbital of vinyl ethers and alkyl maleates support that these monomer pairs have tendency to form alternating copolymers.With 2-cyanopropan-2-yl N-methyl-N-(pyridin-4-yl)carbamodithioate as the RAFT agent,the molecular weight of HEVE and DMM copolymer increases with the monomer conversion,demonstrating a controlled radical polymerization feature with well-controlled molecular weight and relatively narrower molecular weight distribution.With alternating copolymer of HEVE and DMM as macro-CTA(M_(n)=5200 and M_(w)/M_(n)=1.46),both the chain extension with HEVE and DMM(M_(n)=10400 and M_(w)/M_(n)=1.72)and block copolymerization with vinyl acetate have been successfully achieved(M_(n)=8500 and M_(w)/M_(n)=1.52).

氯乙烯/异丁基乙烯基醚乳液共聚物的合成

以(NH4)2S2O8/Na2SO3/CuSO4为氧化-还原引发体系、十二烷基硫酸钠(SDS)为乳化剂,采用间歇乳液聚合合成氯乙烯/异丁基乙烯基醚(VC/IBVE)共聚物。结果表明,当投料单体中IBVE质量分数增加时,相同聚合时间的聚合转化率和共聚物特性粘度明显降低,当转化率小于70%时,共聚物平均组成变化不大;聚合温度增加使聚合速率增加,但共聚物特性粘度减小;SDS浓度对聚合速率和共聚物特性粘度的影响很小;随引发体系浓度增加,聚合速率增加,共聚物特性粘度变化不大。

淀粉/BA-VAc接枝共聚物的合成及应用研究

以过硫酸铵为引发剂，研究了玉米淀粉与丙烯酸丁酯和醋酸乙烯酯接枝共聚合反应的规律。实验结果表明，单体浓度０．９７ｍｏｌ／Ｌ，引发剂浓度９．１×１０－３ｍｏｌ／Ｌ，反应温度６８℃，反应３ｈ时，反应体系的接枝率较高。通过红外光谱和Ｘ射线粉末衍射对接枝共聚物进行了结构分析。笔者以该接枝共聚物为基料，采用计算机辅助法设计出最优工艺配方。