Electro-copolymerisation of indene and styrene

Electroinitiated cationic copolymerisation of indene and styrene was investigated by constant potential electrolysis. Effects of copolymerisation potential and temperature on the copolymer composition and the reactivity ratios are discussed. The reactivity ratios of the monomers were calculated according to the integrated Lewis-Mayo equation.     

Synthesis and characterisation of N-toluyl methacrylatoethyl carbamates,homopolymers and copolymers with methyl methacrylate

The paper describes the synthesis of N-2/4-toluyl methacrylatoethyl carbamates using 2/4-toluyl isocyanate and 2-hydroxyethyl methacrylate. Homopolymerisation and copolymerisation of these novel monomers with methyl methacrylate was carried out using benzoyl peroxide as an initiator and tetrahydrofuran as solvent. Photopolymerisation of N-4-toluyl methacrylatoethyl carbamate could be carried out without the use of photosensitiser. Structural characterisation of copolymers was done using ¹H-NMR. Thermal stability of copolymers was evaluated in a nitrogen atmosphere by dynamic thermogravimetry.     

Studies of the copolymerisation of acrylic acid with n‐butyl vinyl ether

BACKGROUND: Copolymers of acrylic acid (AA) are important materials for the preparation of glass ionomer cements. Copolymerisation of AA is widely used to alter the acid strength of the material and to increase the number of salt bridges formed in cements. In this paper we report the copolymerisation of AA with n‐butyl vinyl ether (BVE) to form unique copolymers of the hemiacetal ester and with BVE incorporated into the main chain. RESULTS: AA and BVE undergo a spontaneous reaction to form a hemiacetal ester which can itself undergo free radical copolymerisation. The kinetics of this reaction in the bulk state have been examined. In addition, under these conditions BVE is incorporated into the polymer main chain via a free radical mechanism. CONCLUSION: Novel copolymers of the hemiacetal ester and BVE have been prepared in this study. The hemiacetal side chains are labile under moderate heating, being converted back to the acid analogue. Copyright © 2009 Society of Chemical Industry     

微乳液共聚自交联印花粘合剂及其应用

以过硫酸铵和N，N，N’，N’-四甲基乙二胺为引发剂，对功能性单体丙烯酸、丙烯酰胺、N-羟甲基丙烯酰胺与甲基丙烯酸甲酯、丙烯酸丁酯、丙烯腈等采用半连续微乳液聚合方法进行共聚，获得含固量高达44．0％、总乳化剂质量分数小于2．0％、平均粒径小于50nm的微胶乳。该微乳液较之常规乳液具有粒径小且分布均匀、摩擦牢度高、手感柔软、得色好、成膜透明光洁和存贮稳定等优点，适于用作涂料印花的粘合剂。     

含氟丙烯酸酯共聚物表面施胶剂的制备及应用

以2-(N-甲基全氟辛烷基磺酰基)乙基丙烯酸酯(FM),丙烯酸丁酯(BA)、苯乙烯(St),甲基丙烯酸二甲胺乙酯(DM)为原料,采用无皂乳液聚合制得了阳离子含氟丙烯酸酯四元共聚物乳液.单独使用含氟乳液对纸张进行表面施胶,水和油滴在纸张上所成接触角最大可分别达到107.和93.,同时纸张的抗张强度、耐折度、白度分别提高12.46%、68.42%、0.66%.将淀粉和含氟乳液以不同质量比复配应用,讨论了复配体系对纸张防水防油性、强度、白度的影响.最后初步探讨了含氟乳液的施胶机理.     

D4-丙烯酸酯水性胶粘剂的研制

研究了以ＯＰ－１０、十二烷基硫酸钠为乳化剂，以Ｋ２Ｓ２Ｏ８为引发剂，以八甲基环四硅氧烷（Ｄ４）与丙烯酸丁酯为主要单体，进行乳液聚合反应，制取水性胶粘剂。在固含量一定的前提下，通过正交试验确定了最佳粘结强度的条件。     

In situ generated half-lanthanidocene based catalysts for the controlled oligomerisation of styrene: Selectivity, block copolymerisation and chain transfer

The Cp^∗Nd(BH₄)₂(THF)₂/n-butylethylmagnesium combination affords a controlled and syndioselective oligomerisation of styrene. Living oligostyrenes can be used as macromonomers for block copolymerisation, leading to the unprecedented synthesis of a (polystyrene)-block-(1,4-trans polyisoprene) copolymer. Reversible transmetallation between the neodymium and the magnesium atom is further established with a transfer efficiency close to 100%.     

Free radical initiation mechanisms in copolymerisation studied by the nitroxide trapping technique

The initiation mechanism for the radical copolymerisation of vinyl acetate, a typical electron donor monomer, and acrylonitrile, a typical electron acceptor monomer, initiated by t-butoxy radicals, has been investigated by the nitroxide radical trapping technique: 1,1,3,3-tetramethyl-1,3-dihydroisoindol-2-yloxyl (T) was the radical trapping agent. Two adducts (diastereomers) containing both vinyl acetate and acryionitrile monomers were isolated. From a kinetic analysis of these and other products over a wide range of conditions, a mechanism involving separate monomer addition, which may be regarded as normal kinetic control of monomer addition, is shown to be most consistent with the observed results.     

Ethylene/styrene copolymerisation by homogeneous metallocene catalysts: experimental and molecular simulations using rac-ethylenebis(tetrahydroindenyl)MCl2 [M=Ti,Zr] systems

Styrene was copolymerised with ethylene using the catalyst systems [rac-Et(H₄Ind)₂TiCl₂]/MAO and [rac-Et(H₄Ind)₂ZrCl₂]/MAO. Keeping other experimental variables under control, we tested different styrene/ethylene ratios in the reactor feed. It was found that the titanium-based catalyst showed very low activity even for ethylene homopolymerisation. In contrast, the zirconium system achieved monomer polymerisation, incorporating small amounts of styrene. When the styrene/ethylene ratio was increased, both catalyst activity and the molecular weight of the resulting copolymers decreased. However, styrene incorporation into the copolymer increased as the styrene/ethylene ratio rose. To gain insight into the copolymerisation mechanisms at play, we undertook a computational study using a high-level hybrid DFT method (B3LYP). Agreement between the experimental and theoretical results was generally good, indicating the usefulness of combined experimental/theoretical studies for clarifying mechanisms of -olefin copolymerisation using organometallic systems.     

3-Amino-2-cyano-imidoacrylate ligands and their zinc complexes for the copolymerisation of CO2 and epoxides: Living character and temperature optimisation

Zinc acetate complexes with 3-amino-2-cyano-imidoacrylate ligands exhibit high activities and selectivities in the copolymerisation of carbon dioxide and cyclohexene oxide to give aliphatic polycarbonates. In temperature optimisation experiments, temperatures around 90 °C were found to be ideal combining minimal formation of the cyclic carbonate side product with optimal catalytic activity. The living character of the polymerisation was shown by studying molecular weights of the polycarbonates at different levels of monomer conversion.