丁苯嵌段共聚物溶液粘度影响因素探讨

从聚合物的分子量、合成方法、聚合配方、聚合物的微观结构、单体反应浓度等方面探讨了聚合物溶液粘度的影响因素。     

氨纶聚合反应中的平均相对分子质量计算

根据高分子化学的逐步聚合理论,提出了氨纶预聚和扩链反应中聚合物平均相对分子质量计算的方法,对氨纶聚合工艺配方设计有重要的指导意义。     

中国专利

原子转移自由基聚合制备聚甲基丙烯酸叔丁酯大分子单体,一种消除聚合物中残留单体N-乙烯基吡咯烷酮的方法，用于气相烯烃聚合的负载型催化剂，用于烯烃聚合的组分和催化剂,制备用于皮肤和头发组合物的乙烯基酰胺聚合物的方法[编者按]     

气相法铬系聚乙烯催化剂QCP-01的改进

从催化剂配方和制备工艺条件方面对QCP-01气相法铬系聚乙烯催化剂进行了改进,达到了适当降低催化剂聚合活性并提高聚合物熔融指数的目的。     

聚氯乙烯溶液粘度的经验公式及其应用——正确确定聚合反应温度、避免聚合物转级的方法

一、前言 氯乙烯的聚合反应要达到产品质量好,聚合时间短,除与单体质量、引发剂种类及配方有关外,还决定于釜温。因为在氯乙烯聚合中,釜温不仅影响聚合反应的速率,即聚合时间,而且还影响聚合物的分子量(平均聚合度或粘度),即影响聚合物的质量。如何控制聚合物的平均聚合度,有意识地按照所需要的粘度进行生产,避免产品转级,是从事聚氯乙烯工业     

热塑性弹性体配方设计技巧(一)

继橡胶、塑料后,作为第三聚合材料出现的热塑性弹性体(TPE)正方兴未艾,倍受瞩目。介绍了TPE的特点,配方设计诀窍,聚合物、配合剂的选用,聚合物共混增容工艺技巧,以及性能改善方法。     

热塑性弹性体配方设计技巧(二)

继橡胶、塑料后,作为第三聚合材料出现的热塑性弹性体(TPE)正方兴未艾,倍受瞩目。介绍了TPE的特点,配方设计诀窍,聚合物、配合剂的选用,聚合物共混增容工艺技巧,以及性能改善方法。     

热塑性弹性体配方设计技巧(三)

继橡胶、塑料后,作为第三聚合材料出现的热塑性弹性体(TPE)正方兴未艾,倍受瞩目。介绍了TPE的特点,配方设计诀窍,聚合物、配合剂的选用,聚合物共混增容工艺技巧,以及性能改善方法。     

热塑性弹性体配方设计技巧(四)

继橡胶、塑料后,作为第三聚合材料出现的热塑性弹性体(TPE)正方兴未艾,倍受瞩目。介绍了TPE的特点,配方设计诀窍,聚合物、配合剂的选用,聚合物共混增容工艺技巧,以及性能改善方法。     

多功能阻燃剂

它是由环氧氯芮烷、三氯化磷、三乙醇胺在催化剂下进行开环聚合而成。在聚合物中加入本阻燃剂,可使聚合物同时具有阻燃、增塑、抗氧化、抗静电功能,大大减少生产配方     

Macroporous polymers from particle-stabilized emulsions

Macroporous polymers are attractive materials due to their low density, low cost, recyclability and tunable mechanical and functional properties. Here, we report a new approach to prepare macroporous polymers from emulsions stabilized with colloidal polymeric particles in the absence of chemical reactions. Stable water-in-oil emulsions were prepared using poly(vinylidene difluoride) (PVDF), poly(tetrafluoroethylene) (PTFE), and poly(etheretherketone) (PEEK) as stabilizing polymeric particles in emulsions. The partial wetting of the polymeric particles by the two immiscible liquids drives particles at the water-oil interface during emulsification, leading to extremely stable water-in-oil emulsions. The particle-stabilized emulsions were processed into highly porous solid polymer components upon drying and sintering. The high stability of emulsions also allows for the preparation of hollow polymeric microcapsules. We describe the conditions required for the adsorption of particles at the liquid-liquid interface, we show the rheological behavior of the polymer-loaded wet emulsions and, we discuss the effect of the emulsions' initial compositions on the final sintered porous structures. This new approach for the fabrication of macroporous PVDF, PTFE, and PEEK polymers is particularly suited for the preparation of porous materials from intractable polymers but can also be easily applied to a variety of other polymeric particles.     

Filled polymers with high nanoparticles concentration—Synthesis and properties

High refractive index optical compositions based on polymer matrices filled with high concentrations of ZnS nanoparticles were developed. These materials have good optical properties and processability like usual polymers, and they are suitable for factory scale use. At 25 vol % ZnS nanoparticles concentration an increase in refractive index up to 0.25 in 150 um transparent film was obtained. A process was develope for formation of polymeric compositions consisting of polymer filled with high concentrations of inorganic crystalline nanoparticles. Effects connected to high concentration of nanoparticles in the polymer were discussed. Optical properties of these materials were investigated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Microkinetics of high-temperature pyrolysis

High-temperature pyrolysis of various classes of polymers have been discussed. For the non-carbonizing polymers it was shown that polymer structure can affect the pyrolysis characteristics. Data on the high-temperature pyrolysis of some polypropylene samples with different crystallinity have been presented. Modification of the standard method allowing one to obtain kinetic data from the single experiment was discussed. A kinetic model for the degradation of char-forming polymers in conditions of high-temperature pyrolysis has been suggested. It has been supposed that pyrolysis of carbonizing polymers proceeds in some (two in present work) parallel stages with different activation energies, temperatures and pyrolysis rates. Questions of the applicability of the suggested model to describe the various types of charring systems have been discussed. High-temperature pyrolysis for a number of epoxy resin-based polymeric compositions have been investigated. Kinetic parameters of the pyrolysis have been computed. © 1998 John Wiley & Sons Ltd.     

Poly(alkylene oxide) ionomers: 1. Copolymerization of trioxane by gas phase mixing of comonomers and initiator

Uniform copolymers of trioxane with 1,3-dioxolane and ethyl glycidate of various comonomer compositions were prepared. A special reactor was used which allowed mixing of comonomers and initiator in the gas phase above the polymerization temperature of the mixture. Polymerization was accomplished by rapidly quenching the initiated mixture to dry ice temperature, giving polymer yields in excess of 80%. The polymers were either base treated or endcapped with propionic anhydride to obtain stable materials. The copolymers of trioxane and ethyl glycidate were treated with sodium hydroxide in aqueous dioxane at 85°C to give polyoxymethylene (POM) ionomers. The polymeric sodium salts could also be exchanged to other alkali salts of POM ionomers with various alkali chlorides while the polymers were either in suspension or in film form. Treatment of the sodium salts with acetic acid gave the free POM carboxylic acids. All polymers were characterized by their inherent viscosity, infra-red spectrum and p.m.r. spectrum.     

Role of specific interactions on fiber formation in the electrospinning of poly(vinyl phenol)/poly(vinyl pyrrolidone) blend solutions

The minimum concentration (C_i) required for electrospinning polymeric fibers from solutions of mixtures of poly(vinyl phenol) and poly(vinyl pyrrolidone) has been experimentally determined for different blend compositions. This minimum concentration C_i has its lowest value when the polymers are mixed in a 1/1 molar ratio. This article shows different results that seem to indicate that the strong hydrogen bonding interactions between the two polymers and the corresponding higher apparent molecular weight cause the reduction of the C_i value. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

A new cationic surfactant N,N′-dimethyl-N-acryloyloxyundecyl piperazinium bromide and its pH-sensitive gels by microemulsion polymerisation

A piperazine-based cationic surfactant, N,N′-dimethyl-N-acryloyloxyundecyl piperazinium bromide (DAOUPB) was synthesised by a two-step procedure. The monomer was polymerised in two new microemulsion systems: (i) DAOUPB/water/methyl methacrylate (MMA):hydroxyethylmethacrylate (HEMA) and (ii) DAOUPB/water/acrylonitrile with ethyleneglycol dimethacrylate (EGDMA) as the crosslinking agent. Transparent solid polymeric materials were obtained by photo-initiated polymerisation of some of these microemulsion compositions. Most of the bicontinuous microemulsions investigated gelled within 10 min resulting in transparent solid polymers. The electron micrographs of the polymers obtained from microemulsion compositions containing MMA:HEMA did not show any micropores, while those obtained using acrylonitrile revealed the existence of open-cell type micropores and also of the bicontinuous nature of the system. The width of the bicontinuous structure (micropores) was about 33 nm in the dry state, with long and winding channels of random distribution. The swelling of the gels was highly sensitive to pH.     

高分子材料的发展现状与趋势

在强调高分子材料高性能化、高功能化、复合化、精细人和智能化发展的基础上，较详细地这了高分子合成技术的发展，三大合成材料工业的现状与趋势，以及未来高分子材料发展中几个重要的领域；工程塑料、复合塑料、液昌高分子、高分子分离材料和生物医用高分子材料。     

Syntheses and magnetic properties of novel bithiazole‐containing polymeric complexes

Three novel bithiazole‐containing polymers were synthesized from 2,2′‐diamino‐4, 4′‐bithiazole (DABT) condensed with bismaleimide, bis(methyloxycarbonyl ethyl)tin dichloride (BETD), and 4,4′‐diphenylmethane diisocyanate (DPDI), respectively. A new series of polymeric complexes were prepared from Fe²⁺ and the three polymers. These polymers and their complexes were characterized through FTIR, ¹H‐NMR, and related techniques. The chemical compositions of the complexes were determined by XPS. The presence of the exchange interaction between the unpaired electrons was investigated by ESR spectroscopy. The magnetic behavior of these complexes was measured as a function of the magnetic field strength (0–40 kOe) at 5 K and as a function of temperature (5–300 K) at a magnetic field strength of 30 kOe. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1353–1359, 2001     

Low-Cost Processing of Plastic Waste Composites

The use of the compression molding technique to manufacture polymeric panels from recycled polymers was evaluated. polypropylene (PP), polyethylene (PE), and polystyrene (PS) single polymers and their blends were manufactured both with and without UV and flame-retardant additives. The materials were tested in three-point bending, and the incorporation of the additives always produced a decrease of the flexural strength. The results obtained were compared with the properties of commercially available materials. In particular, PP + PE blends showed a promising mechanical performance. For the amount of flame-retardant additive used in this study, none of the compositions analyzed exhibited flame resistance. The balance between loss of mechanical strength due to the increase of the amount of flame retardant additive and lack of flame resistance was obtained by incorporating more flame retardant through a paintinglike procedure. The method proved to be an efficient way to attend the standard for building construction panels.     

Formation of palladium fullerides and their thermal decomposition into palladium nanoparticles

Formation of palladium fullerides from various Pd:C₆₀ compositions was studied by XRD, Raman spectroscopy and TEM. Raman spectra of Pd_xC₆₀ samples show close similarity to spectra of C₆₀ polymers obtained under high pressure/high temperature conditions and suggest the formation of chain-like and two-dimensional polymeric structures in Pd_xC₆₀ of various compositions. Thermal decomposition of Pd_xC₆₀ results in the formation of fine 5-10 nm size nanoparticles of palladium which can be used for catalytic applications.