Functional Polymers. XXVI. Co- and Terpolymers Involving Methacrylates,N-Vinylpyrollidone,and Polymerizable Ultraviolet Stabilizers and Antioxidants

2(2-Hydroxy-5-isopropenyl)2H-benzotriazole and 2(2-hydroxy-5-vinylphenyl)2H-benzotriazole, both of which are well-established polymerizable ultraviolet stabilizers, have been co- and terpolymerized with N-vinylpyrrolidone, 1,1,1-tris(trimethylsiloxy)-methacrylato-propylsilane, and various methacrylate esters. Additionally, 4-isopropenyl-2,6-ditertiarybutyl phenol was co-and terpolymerized with these monomers as such to provide polymer compositions stable against autoxidation or in combination with the 2(2-hydroxy-5-isopropenylphenyl)2H-benzotriazole to provide stability against autoxidation and photooxidation. The polymerizations resulted in insoluble polymers from which the ultraviolet stabilizer or the antioxidant could not be extracted or leached out. The stabilized polymers had water absorption behavious similar to that co- and terpolymers without the incorporation of the polymerizable stabilizers.     

Polymers Based on Epoxy Resins and Functional Derivatives of Polychlorobiphenyls

A new way to utilize polychlorobiphenyls was suggested: transformation of Sovol base hydrolysis products into glycidyl ethers and titanates. The resulting products were tested as components of epoxy compounds which are subsequently cured to obtain three-dimensional polymer networks.     

Thermoplastic Xylan Derivatives with Propylene Oxide

Polymeric xylan can be reacted with propylene oxide (PO) in aqueous alkali homogeneously. Since xylan is isolated from biomass in aqueous alkaline solution, an in-line modification with PO as part of the isolation protocol, is most practical. Hydroxypropyl xylan (HPX) is a low molecular weight, branched, water-soluble polysaccharide with low intrinsic viscosity and thermoplasticity. Following peracetylation of HPX in formamide solution, water-insoluble acetoxypropyl xylan (APX) is formed that is also thermoplastic but no longer water soluble. The glass transition temperature (T _g) of APX varies in relation to degree of substitution with hydroxypropyl groups (DS_PO), and this is found to decline from 160 to 70°C as DS_PO rises from 0.2 to 2.0. At a temperature above the T _g of HPX a molecular reorganization is noted, and a faint transition due to melting (T _m) is observed at 205°C. HPX thermally degrades with a weight loss maximum at 317°C, or approximately 60°C below that of a corresponding cellulose derivative. HPX forms clear films when solvent cast from aqueous solution. Films are higher in ultimate tensile strength and lower in toughness than corresponding cellulose derivative films. The properties of HPX and APX derivatives qualify this material as a potential biodegradable and thermoplastic additive to melt-processed plastics. Blend characteristics with polystyrene reveal a shear-thinning effect in melt and a plasticization effect in solid state.     

Functional Polymers. XXV. Fluorescence Spectra of Derivatives of Methyl Salicylate and Copolymers of Methyl Vinylsalicylates

Ultraviolet absorption and fluorescence spectra of methyl salicylate, isomers of methyl salicylate derivatives, and polymers with units of isomers of methyl salicylate have been investigated. The λ_max of methyl salicylate and its derivatives is centered around 310 nm. When the phenolic hydroxyl group is acetylated, the maximum is at 285 nm. Fluorescent emission maxima depend on the excitation wavelength. Two groups of maxima centered at 350 and 460 nm indicate that two molecular species (already present in the ground state) of the methyl salicylate moiety, probably tautomers, play essential parts as photoexcited states in the photophysics of methyl salicylate derivatives.     

On the Epimerization of endo-Dicyclopentadiene during Terpolymerization with Ethylene and Propylene

The isomerization of endo-DCP (I) to exo-DCP (II) during the synthesis of EPDM with several Ziegler-Natta catalysts has been investigated by means of IR spectroscopy and by reference to EPDM containing different levels of true exo-DCP. The I - II epimerization was absent for ail the catalysts examined. Only with the systems VC1₄-Et₂AlCl was a trace of isomerization observed, and then only at the limit of sensitivity of the analytical method. No isomerization was detected via gas-chromatographic analysis in monomeric DCP recovered from the polymerization mixture. Ziegler-Natta catalysts having acidic character can homopolymerize I, but epimerization was observed only with the system voc1₃-Et₃Al₂Cl₃. The results obtained have been interpreted in terms of a terpolymerization mechanism having a prevalent coordinated character. The poly functionality of Ziegler-Natta catalysts is sometimes responsible of the secondary isomerization process.     

Functional Polymers. III. Endcapping and Substitution on Polymers with Compounds Containing Ultraviolet-Absorbing Groups

Endcapping of oligo(oxyethylene) glycols was carried out by transesterification of methyl N,N-dimethylaminobenzoate with sodium methoxide as the catalyst or by the reaction of sodium salicylate with the ditosyl ester of the oligo(oxyethyl-ene) glycols. Several other common reactions were tried for the endcapping of the oligo(oxyethylene) glycols but were found to be either more cumbersome or unsuccessful. All products were obtained in high yield and high purity. The reactions of tetraalkylammonium carboxylates with aliphatic halides were found to be very general and mild reactions for the preparation of esters in high yield and high purity. It was found that these reactions could be utilized for the preparation of esters on polymers even if the carboxylate group was directly attached to the polymer chain. It was also demonstrated that the aliphatic halide group could be on the polymer, as in the case of polyepichlorohydrin. Copolymers of epichlorohydrin and glycidyl N,N-dimethylaminobenzoate with up to 90% glycidyl benzoate as the comonomer were prepared, and poly(tetra-butylammonium methacrylate) was effectively transformed with 4-(2-bromoethoxy)-2-hydroxybenzophenone into the corresponding ester. The products were characterized by the usual spectral means.     

Raman Structural Study of Copolymers of Propylene with Ethylene and High Olefins

Nascent form of random copolymers of propylene with ethylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene was studied by Raman spectroscopy. The most significant spectral alterations with a change in propylene content were observed in two lines at 809 and 841 cm⁻¹. The first line corresponds to vibrations of polypropylene helical chains in the crystalline phase, while the second one is associated with vibrations of polypropylene helical chains having isomeric defects. Raman data confirm that conformational composition and phase state of copolymer macromolecules strongly depend on the comonomer content as well as on the size of the comonomer units.     

环氧乙烷环氧丙烷共聚醚的研究进展

综述了环氧乙烷环氧丙烷共聚醚的聚合机理聚合工艺及其应用.环氧乙烷环氧丙烷共聚醚的聚合按其催化剂体系的机理可以分为阴离子聚合、阳离子聚合和配位聚合三类,其中阳离子聚合应用较少.在环氧乙烷和环氧丙烷开环聚合生成共聚醚的反应中,不同的反应工艺条件对生成的聚醚有着很大的影响.同样比例的环氧乙烷和环氧丙烷,因聚合反应器设计、反应器种类、起使剂种类催化剂种类与用量温度加料方式端基结构等的不同,所合成的共聚醚会产生不同的结构和性能.环氧乙烷环氧丙烷共聚形成的聚醚可以分为嵌段共聚醚和无规共聚醚两类.其中,嵌段共聚醚可以分为EPE和PEP两类.     

环氧乙烷环氧丙烷开环聚合反应动力学研究

环氧乙烷和环氧丙烷由于具有较高的环张力,因而容易发生开环聚合。本文综述了环氧乙烷合环氧丙烷开环聚合反应的动力学研究进展,考察了环氧乙烷和环氧丙烷开环聚合反应的机理,分别讨论了各类催化剂体系中环氧乙烷和环氧丙烷开环聚合的动力学常数、两者的竞聚率及开环聚合产物的分子量分布,并指出了开环聚合反应动力学研究对于环氧乙烷和环氧丙烷的开环聚合研究及工业应用的重要性。     

类荷叶结构聚全氟乙丙烯的超疏水性

以聚二甲基硅氧烷（PDMS）复制的荷叶表面微结构为阴模模板,将聚全氟乙丙烯（FEP）粉体置于该阴模模板上,在约0.3 N/cm2的压力,280 ℃和-0.1 Mpa真空度的条件下热压成型,成功制备了具有类荷叶结构的FEP表面。扫描电镜观察结果表明, FEP表面与荷叶表面微结构具有很大的相似性,该表面具有良好的超疏水性,与水的接触角达到168°,滚动角小于3°,而且具有良好的疏酸、疏碱、疏盐溶液性能和稳定性,即使在溶液中长期浸泡而失活后,经piranha洗液处理约10 min,其表面超疏水、疏酸、疏碱性能也可迅速恢复。PDMS的热重分析结果表明,PDMS阴模在热压条件下失重极小,可重复使用。因此,将FEP的耐酸、耐碱、耐腐蚀和低表面能的特性与荷叶表面的特殊结构有机结合,在制备抗粘附、自清洁容器等方面具有广泛的应用前景。     

Arylsulfimide Polymers. I. The Synthesis of m-Bisaccharin and Derivatives

Abstract

m-Bisaccharin and a number of its derivatives have been synthesized. Structural assignments were based on elemental and infrared analyses and, where appropriate, neutralization equivalents and thermal gravimetric analysis.     

茂－茚锆金属络合物催化乙烯/1－己烯共聚和丙稀均聚研究

Complexes （R^1Cp）（R^2Ind）ZrCl2, the catalysts previously reported active for ethylene polymerization showed high activity in ethylene/1-hexene copolymerization and propylene polymerization in the presence of MAO. The content of 1-hexene in copolymers ranged from 1.2% to 3.2%. In propylene polymerization the complex 1 showed the highest activity, up to 1.2×10^6 g of polypropylene per mol of catalyst per hour. Based on the analysis of NMR spectral data, the relationships between complex structures and polymerization results were explored.     

Sorption and Diffusion of Propylene and Ethylene in Heterophasic Polypropylene Copolymers

Summary: Sorption experiments of ethylene and propylene in different polypropylene powder samples, both homopolymer and heterophasic copolymers with different rubber content, have been carried out in a high-pressure magnetic suspension balance at 10 bars pressure and 70 °C. The gross solubilities measured can be well correlated with the rubber content of the polymer samples. Solubility of ethylene and propylene in the rubber phase differ from solubility in the amorphous fraction of the homopolymer, especially the concentration ratio of propylene to ethylene differs significantly between rubber phase and amorphous fraction of the homopolymer. From the slope of monomer uptake, information on kinetics of mass-transfer can be gained. No significant differences were observed in terms of mass-transfer for ethylene and propylene. With increasing rubber content, effective diffusion coefficients increased slightly. By combined sorption studies with powder samples and compressed films, information about both effective diffusion coefficients and the effective length scale of diffusion could be gained. It could be shown, that the particle radius is not the characteristic length of diffusion in the studied powder samples. Mass transfer of nearly all samples could be described by a constant diffusion length of 120 to 130 µm, independently on particle size. This indicates that the effective scale of diffusion in polymer particles is in between microparticle and macroparticle scale used in classical particle modeling.     

乙烯和丙烯自由基共聚反应的多尺度模拟模型

结合量子化学和传统过渡态理论计算了乙烯和丙烯自由基聚合反应的速率常数.利用速率常数定义了聚合反应几率(Pijl),构造了乙烯和丙烯共聚合反应的粗粒化动力学模拟模型,并利用该模型研究了不同组成比的乙烯和丙烯的共聚合反应.发现反应速率常数和链端自由基周围的单体浓度都影响链上组分的序列分布.     

Copolymerization of Carbon Dioxide and Propylene Oxide with Zinc Catalysts Supported on Carboxyl-Containing Polymers

Polymer-supported zinc catalysts were prepared by the reaction of di-ethylzinc with polymers containing carboxyl groups. The catalysts were employed in the alternating copolymerization of carbon dioxide and propylene oxide to give poly(propylene carbonate) of high molecular weight. Copolymers of styrene and acrylic acid were shown to be better catalyst supports than poly(acrylic acid) and some other polymers. Maximum activity was achieved when the molar ratio of Zn/COOH was around unity. The yield and molecular weight of the polycarbonate rose with increasing reaction time. Higher reaction rates but lower molecular weights of the product were observed at elevated reaction temperatures     

Magnetic,Spectral, Thermal,and Electrical Properties of Coordination Polymers Derived from Terpolymers

Coordination polymers of Cu(II), Ni(II), Co(II), zinc(II), chromium(IU), iron(IU), oxovanadium(N), and dioxouranium-(VI) with p-hydroxybenzoic acid (PHB)-thiourea (T)-trioxane (T) (PHBTT) polymer were prepared. The analytical data agree with 1:1 metal-ligand stoichiometry. Magnetic susceptibility, visible and IR spectra, and thermal and electrical conductivities of the chelates have been studied and probable structures assigned to the chelates.     

Supported Chromium Oxide Catalyst for Olefin Polymerization. XI. Comparison between Ethylene and Propylene Polymerization

It is shown that the new model of an active site of chromium oxide catalyst supported on silica-alumina, previously proposed for ethylene polymerization, is also valid for propylene polymerization. The new model involves a set of three chromium atoms with different oxidation degrees located at the border of the flat chromium oxide domains spread onto the support. The main differences between the behavior of the two monomers are caused by the much higher reducing power of the propylene and also by its mode of adsorption which is stronger. Some copolymerization experiments are described.     

Magnetic,Spectral, Thermal,and Electrical Properties of Coordination Polymers Derived from Terpolymers

Coordination polymers of Cu(II), Ni(II), Co(II), Zn(II), Cr(III), Fe(III), oxovanadium (IV), and dioxouranium(VI) with salicylic acid (S)-thiourea (T)-trioxane (T) (STT) polymer were prepared. The analytical data agree with 1:1 metal-ligand stoichiometry. Elemental analyses, magnetic, spectral, and thermal properties, and electrical conductivities of STT and its chelates have been studied and probable structures are assigned to the coordination polymers. All the chelates are amorphous powders, insoluble in common organic solvents, and showing slight solubility in DMF.     

不同序列结构的二氧化碳/环氧丙烷/邻苯二甲酸酐三元共聚物的可控合成及性能研究

利用非金属催化体系,分别通过一锅两步法和一锅一步法,实现了二氧化碳（CO₂）、环氧丙烷（PO）和邻苯二甲酸酐（PA）的本体聚合.通过反应条件优化获得了3种聚酯（PE）链段摩尔组成和分子量较为相近,但分别具有嵌段、梯度和无规序列结构的聚酯-聚碳酸酯共聚物（PPC-P）.通过示差扫描量热法（DSC）、热重分析（TGA）以及拉伸试验对3种不同序列结构的PPC-P进行了热性能和力学性能的比较,其中嵌段PPC-P存在2个玻璃化温度（43和54℃）,而梯度、无规PPC-P只存在一个玻璃化温度（分别为51和50℃）.嵌段PPC-P的5%失重温度比无规和梯度PPC-P的低10℃,说明其热分解稳定性稍差一些. 3种序列结构的PPC-P抗拉性能相当,拉伸强度达到35 MPa,都属于硬而脆的材料.     

Functional Polymers. VIII. Polyesters from Hindered Bisphenols

It was demonstrated that highly hindered bisphenols could be used to produce polyesters of moderate molecular weight. Bisphenols linked in the 4 and 4′ or the 2 and 2′ positions and substituted in positions ortho and para to the phenolic hydroxyl groups with methyl or tertiary butyl groups (these bisphenols are now used as very effective antioxidants) formed polymers, their reactivity depending more on the nature of the group linking the two phenyl rings than on the steric effects of the ortho substi-tuents. Bisphenols linked in the 2 and 2′ positions and containing bulky electron-withdrawing groups were found to be least effective as condensation monomers although successful polymerization to moderate molecular weight could be achieved using me it polycondensation techniques.