Influence of nonionic emulsifiers on the properties of vinyl acetate/VeoVa10 and vinyl acetate/ethylene emulsions and paints

This paper presents results on the influence of the nonionic surfactant on the properties of vinyl acetate/VeoVa10^® and vinyl acetate/ethylene emulsions and paints made thereof. Emulsions were prepared in which the concentration of the nonionic surfactant and its degree of ethoxylation were varied. An increase of the nonionic emulsifier concentration and of the length of the ethylene oxide chain leads to dispersions with smaller particles and higher viscosities. Using these emulsions as binders in high pigmented paints, it was observed that the pigment binding capacity of the interior paints goes through a maximum which is located at a emulsifier concentration of about 2–3% and at a degree of ethoxylation of 17–28 mol ethylene oxide (EO). In (semi-) gloss paints, the gloss of the paint films improves with an increase of the emulsifier concentration and reaches a constant value at around 4% or a degree of ethoxylation of ca. 17 EO-moieties per molecule. The blocking of the films shows a drastic increase at a concentration above 4% and at a chain length of greater than 17 EO-moieties.     

Miscibility and surface crystal morphology of blends containing poly(vinylidene fluoride) by atomic force microscopy

The miscibility and surface crystalline structure of blends containing poly(vinylidene fluoride) (PVDF) composed of and γ phases were investigated by atomic force microscopy (AFM) and differential scanning calorimeter (d.s.c.) measurements. It was found that the surface crystalline phase of PVDF and the degree of surface enrichment of a lower surface free energy component in a blend might strongly be affected by the magnitude of the intermolecular interaction, even though the blend is miscible. Also, the segmental interaction parameters was determined by combining the T_m depression of PVDF in a blend and the binary interaction model. According to the binary interaction model, the introduction of a carboxyl group for miscible [poly(methyl methacrylate)/PVDF] and [poly(vinyl acetate)/PVDF] blends decreased their miscibility.     

自交联丙烯酸酯乳液的制备

讨论了以Ｋ２Ｓ２Ｏ８作为引发剂，使用全滴加法制备自交联丙烯酸酯—醋酸乙烯酯乳液过程中，复合乳化剂用量及相对比例，引发剂用量及滴加时间对聚合反应的影响。同热分解引发剂相比，对相同聚合体系，使用氧化—还原引发体系，可在较低温度聚合得到稳定的乳液。     

A novel polymer chain growing mode and styrene copolymer prepared with low molecular weight copolymer of α‐methylstyrene and styrene as macroinitiator

A new polymer chain growth mode, having multiple potential chain propagation sites, initiated by oligomer of α‐methylstyrene (AMS) and styrene (St) (PAS) is presented in this article. The effects of PAS content, AMS fraction in PAS and reaction temperature on bulk polymerization of St have been investigated. It is demonstrated that the PAS performed as macroinitiator in the polymerization of St. The average molecular weights of products increase significantly with the evolution of the polymerization, which is different from conventional free radical polymerization. With 20 wt % macroinitiator, the molecular weights increase from 1.21 × 10⁵ to 3.00 × 10⁵ with the monomer conversion increasing from 15.3 to 83.0%. This unique feature is tentatively attributed to both the reversible polymerization–depolymerization of AMS segments at high temperature which could generate more than one propagation sites in a polymer chain and the combination termination of St free radical polymerization. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41460.     

PVP系聚合物在发用化妆品中的应用概述

介绍了乙烯基吡咯烷酮(VP)的性质,其均聚物(PVP)的合成,表面活性、成膜性、化学稳定性以及生物特性等性能及其在护发定型类产品中的成膜、护肤类产品中的润滑、保湿及成膜中的应用。概述了发用定型化妆品领域里常用的VP二元共聚物如乙烯基吡咯烷酮/乙酸乙酯共聚物和三元共聚物。     

环保低溶剂型微支链聚酯树脂的研制

低溶剂微支链聚酯树脂是一种新型的具有一定反应能力的增塑剂。是以乙二醇、己二酸为反应主体,加入一些能形成支链的反应物,通过缩聚合成聚合物,同时加入单元酸单体来调节控制分子量,从而得到低分子量达到低溶剂的要求。通过实验得出反应物投料比例:29%乙二醇﹑56%己二酸﹑10%苯甲酸﹑3%甘油、2%苯酐和少量回流用溶剂二甲苯;酯化反应温度为210~220℃、反应时间为5~6h。达到指标后,再采用减压脱溶剂把回流物脱出,能制得较好的低溶剂微支链聚酯树脂。     

Preparation of an adhesive in emulsion for maxillofacial prosthetic

Maxillofacial prostheses is a dental medicine specialty aimed at restoring anatomical facial defects caused by cancer, trauma or congenital malformations through an artificial device, which is commonly attached to the skin with the help of an adhesive. The purpose of our research was to develop a pressure-sensitive adhesive (PSA) based on acrylic monomers, characterizing and determining its drying kinetics, that is to say the time it takes to lose 50 to 90% of its moisture. The adhesive synthesis was realized by means of emulsion polymerization; the composition of formulations was: (AA-MMA-EA) and (AA-MMA-2EHA) with different molar ratios. The formulation based on (AA-MMA-2EHA) with 50 w% of solids, presented good adhesive properties such as tack, bond strength, and short drying time. We propose this formulation as a PSA, because it offers an alternative for systemically compromised patients, by less irritation compared to organic solvent-based adhesives.     

含氟单体接枝真丝的性能研究

研究了真丝经含氟丙烯酸单体改性后织物的拒水拒油性、机械性能等．结果显示接枝后丝织物的拒水拒油性能均优于未接枝的丝织物；其中经甲基丙烯酸六氟丁酯接枝改性的丝织物仅能获得较佳的拒水效果，而经甲基丙烯酸十二氟庚酯接枝改性的丝织物拒水拒油效果均较好。     

苎麻棉混纺织物的生产工艺优化

探讨苎麻棉混纺织物的生产要点。介绍了两种苎麻棉混纺织物的规格及对经纱的质量要求;针对混纺纱的特点,采取了一些列技术措施;整经速度偏低掌握,控制在250m/min~300m/min;采用HS-30型浆纱机,优化浆料配方和浆纱工艺,保证浆纱贴伏毛羽,使纱线柔韧耐磨;织造工序采用ZAX-e-280型喷气织机,保证开口清晰,织机效率可达83.6%;严格控制各工序车间温湿度;后整理工序中,使用酶退浆,改善织物服用性能;测试结果表明:开发的织物具有良好的机械性能和服用性能。认为:针对混纺纱特点,采取上述技术措施可以保证产品顺利生产。