汽巴推出两款新型分散剂产品

汽巴公司（Ciba）日前面向工业涂料和汽车涂料领域推出了两款新型的分散剂产品,分别是CibaEFKA4310和CibaEFKA4320,用于改善颜料在涂料体系中的分散效果,并增加颜料与涂料树脂的相容性,从而提高柔韧性,也有利于降低涂料的生产成本。这两种助剂采用了可控自由基聚合技术（CFRP）,这也是添加合成领域的创新技术之一。这种聚合技术可以很好地控制分子结构,以实现更多的添加剂功能。     

涂料用固体丙烯酸树脂的悬浮聚合研究

本文系统考察了悬浮聚合中影响涂料用固体丙烯酸树脂分子量及其分布的各种因素；对丙烯酸酯的悬浮二元共聚及加入第三组分共聚进行了研究，考察了不同单体对产物的影响；并且探讨了悬浮聚合的稳定性和粒径大小的影响因素，确定了合成涂料用固体丙烯酸酯较好的工艺条件。     

共聚法合成可熔纺聚丙烯腈树脂

综述了共聚法合成可熔纺的聚丙烯腈树脂的方法 ,介绍了国外主要的研究成果 ,讨论了自由基乳液聚合、悬浮聚合、交替共聚、活性聚合和模板聚合等聚合方法 ,并对这些方法进行了初步评价。指出自由基乳液聚合或悬浮聚合 ,应该是国内目前研究的重点 ,而原子转移自由基聚合有可能成为最有前途的可控聚合方法。     

活性可控聚合制备热塑性弹性体研究进展

从负离子聚合、正离子聚合、开环聚合、可控自由基聚合等聚合方法入手,总结了不同类型热塑性弹性体合成技术的研究进展,以及其他如超分子化学与聚合物合成相结合等热塑性弹性体研究的新领域和新方向。     

可控自由基聚合及其在涂料工业中的应用浅析

简要介绍了可控自由基聚合技术,探讨了可控自由基聚合技术在工业化方面存在的优缺点以及发展趋势。同时对可控自由基聚合产品的商品化及其在涂料工业领域的应用情况进行了简述。     

用于分散有机颜料和炭黑的润湿分散剂的选择

总结了用于分散有机颜料和炭黑的润湿分散剂的选择方法,介绍了润湿分散剂的类别,重点介绍了可应用于分散上述颜料的新型润湿分散剂,即以可控聚合方法(CPT)所合成的高分子聚合物润湿分散剂。同时介绍了专用于有机颜料和炭黑的一种特殊形态的分散助剂即颜料分散增效剂。最后阐述了涂料配方开发实验室常用的各种评价方法,包括对颜料浆的评价和对最终涂料及涂膜性能的评价方法。     

影响丙烯酸树脂粘度的工艺研究

在涂料用丙烯酸酯树脂的合成中,通过研究不同引发剂在不同工艺条件下对树脂产物的影响,以及不同溶剂对树脂的溶解性能,为生产实践中设计和控制树脂粘度寻找了一些方法,也为制作某些特性树脂而选用合成工艺、引发剂和溶剂提供了思路。     

非均相聚合改性酚醛树脂的研究

本文介绍了酚醛树脂的增韧和耐热改性方法,并用悬浮聚合和乳液聚合方法对酚醛树脂改性进行了探讨,证明了具有特殊性能的酚醛树脂不但可以用本体法和乳液法合成,还可用悬浮法合成;悬浮法生产的粒状热塑性酚醛树脂可以取代进口树脂。本文还介绍了此类改性树脂的一些应用领域。     

反相悬浮法合成PNaAA高吸水性树脂的聚合工艺

采用反相悬浮法合成PNaAA高吸水性树脂。研究了聚合初始温度、搅拌转速、分散剂的种类及用量等对聚合稳定性、树脂粒径和吸水性能的影响。结果表明:在聚合初始温度为50℃、以Span-60为分散剂、分散剂用量为4.4%(相对于单体质量)及搅拌转速为500r.min-1的条件下,聚合过程稳定性好,树脂粒径适中、饱和吸水率高、吸水速度快。     

聚氨酯丙烯酸涂料用高固体分树脂的研制

本文通过对丙烯酸高固体分聚氨酯涂料用树脂的合成研究,讨论了合成所需原材料的选择,介绍了树脂配方及聚合工艺,阐述了其在木器涂料中的应用。     

Microwave-Assisted RAFT Polymerization

Advances in controlled radical polymerization (CRP) have facilitated access to well-defined polymers with controlled molecular weight, topology, and functionality. However, despite the benefits afforded by many CRP techniques, control over these key polymer attributes often comes at the expense of polymerization rate. One method proposed for accelerating chemical synthesis is microwave heating. This review highlights recent examples of microwave heating being applied during reversible addition-fragmentation chain transfer (RAFT) polymerization. In addition to successfully leading to homopolymers from a variety of monomers, block copolymers have also been prepared by microwave-assisted RAFT, which suggests that the high polymerization rates observed do not necessarily lead to significant end group loss from termination. Despite significant debate regarding the origin of rate enhancement observed during microwave-assisted reactions, the reports included herein provide insight into mechanisms by which well-defined functional polymers can be prepared in an accelerated fashion.     

Organometallic mediated radical polymerization

Controlled radical polymerization has become increasingly important over the past decade and a half, allowing for the facile synthesis of specific macromolecular architectures with excellent control over the chemical and physical properties. This article presents an organized and detailed review of one particular CRP technique, organometallic mediated radical polymerization (OMRP), focusing on the individual catalysts developed, their efficacy and monomer scope. Rhodium, cobalt, molybdenum, osmium, iron, palladium, titanium, chromium and vanadium mediated radical polymerizations are presented alongside organo-main group mediated reactions. A separate section reviews the types of copolymers which have been synthesized using OMRP techniques. An attempt is made to unify the many disparate names which have previously been used for OMRP by virtue of the common mechanistic aspects displayed by the different catalyst systems. A mechanistic discussion highlights the similarities and differences between these systems and examines the interplay between reversible termination and degenerative transfer OMRP and competing 1-electron redox processes.     

Controlled radical copolymerization of multivinyl crosslinkers: a robust route to functional branched macromolecules

Controlled radical polymerization (CRP) has both revolutionized the synthesis of linear polymers and enabled unprecedented topological complexity. While the synthesis of many polymeric architectures requires careful planning and specialized precursors, branched macromolecules such as segmented hyperbranched polymers (SHPs), knotted polymers, core‐crosslinked stars (CCSs), and more can be synthesized through the copolymerization of vinyl monomers and divinyl crosslinkers in only a few steps. In the nearly two decades since its discovery, this strategy has helped elucidate the fundamental polymerization behavior of crosslinkers and also yielded a variety of functional and stimuli‐responsive materials. The purpose of this mini‐review is to therefore overview critical fundamental aspects of CRP of crosslinkers and materials derived therefrom. The process by which both SHPs and CCS polymers are synthesized, the effect of key reaction parameters and intriguing recent advances are described with the intent of both educating new researchers and inspiring new directions in this area. © 2020 Society of Industrial Chemistry     

金属罐用热固性丙烯酸树脂的研制

用环氧树脂和丙烯酰胺反应,形成环氧酰胺树脂后,再与丙烯酸及其衍生物、苯乙烯等单体用自由基溶液聚合方式,将环氧接枝到丙烯酸树脂上。通过研究确定了树脂合成的最佳工艺,讨论了各种因素对涂料性能的影响。     

Modeling and theoretical development in controlled radical polymerization

Controlled radical polymerization (CRP) systems have gained increasing interests for the past two decades. Numerous publications may be found in the literature reporting experimental and modeling work on various CRP processes, including their use in surface modification through grafting. Knowledge of underlying mechanism behind polymerization systems is valuable for product design and process optimization. This information may be obtained through the combination of modeling and experimental studies. In this review, published studies on kinetic and stochastic based modeling for CRP systems are summarized. Their relevance in model discrimination of proposed mechanisms is discussed. This review also includes various parameter estimation studies, that is crucial to obtain accurate simulation predictions. Existing issues on the fundamental mechanism in CRP processes are also addressed.     

水溶性丙烯酸树脂的制备研究

用于水性油墨的水溶性丙烯酸树脂由丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)三种单体采用传统的自由基溶液聚合方式合成,通过大量的对比实验筛选了各种不同的反应条件,获得了最佳合成工艺,包括引发剂、溶剂、加料方式、聚合时间和温度。对影响树脂性能的指标如共聚物组成、玻璃化转变温度Tg等各种因素,采用DSC、IR等分析方法进行了详尽的分析和表证。     

The strength of multi-scale modeling to unveil the complexity of radical polymerization

The strength of multi-scale modeling to support the fundamental understanding and design of radical polymerization processes is illustrated, considering both controlled and free radical polymerization (CRP/FRP) in non-dispersed (bulk/solution) and dispersed (suspension/emulsion) media. At the molecular scale, the importance of joint experimental and theoretical studies is highlighted. At the micro-scale, the concept of apparent rate coefficients is elaborated to account for the possible influence of diffusional limitations on the local reaction rates. At the meso-scale, the key characteristics to fundamentally describe the evolution of the particle size distribution are covered and the possible interaction with the micro- and macro-scale is discussed. At the macro-scale, the main mathematical tools to assess the relevance of mixing and temperature gradients are provided. Several examples on CRP and FRP processes are included to showcase the modeling capabilities for each scale, focusing both on laboratory and industrial reactors.     

Molecularly imprinted polymers via living radical polymerization: Relating increased structural homogeneity to improved template binding parameters

This work examined imprinted polymer networks prepared via controlled/living radical polymerization (LRP) and conventional radical polymerization (CRP) on chain growth, network formation, and efficiency of producing molecularly imprinted, macromolecular memory sites for the template molecule, diclofenac sodium. LRP extended the reaction-controlled regime of the polymerization reaction and formed more homogeneous polymer chains and networks with smaller mesh sizes. In addition, LRP negated the effect of the template on polymer chain growth resulting in polymers with a more consistent PDI independent of template concentration in the pre-polymerization solution. Improved network homogeneity within imprinted poly(HEMA-co-DEAEM-co-PEG200DMA) networks prepared via LRP resulted in a 38% increase in template binding affinity and 43% increase in the template binding over imprinted networks prepared via CRP and a 97% increase in affinity and 130% increase in capacity over non-imprinted networks prepared by LRP. By varying certain parameters, it was possible to create imprinted networks with even higher template binding affinities (155% over non-imprinted) and capacities (261% over non-imprinted). This work is the first to conclusively demonstrate that the observed improvement in binding parameters in weakly crosslinked, imprinted polymer networks could be explained by the more uniform molecular weight evolution associated with the LRP mechanism and the longer lifetime of an active polymer chain relative to the total polymerization time, which allowed for the formation of a more homogenous imprinted polymer network.     

Prospects in the application of a frontally curable epoxy resin for cured-in-place-pipe rehabilitation

Photocurable acrylates and vinyl esters are among the most commonly used resins in cured-in-place-pipe (CIPP) rehabilitation technology, as they impart excellent thermomechanical properties in composite pipes. In the quest for achieving a higher energy efficiency of the photo-curing process in CIPP, the frontal polymerization technique is a viable alternative that requires a lower irradiation dosage coupled with exceptionally high curing speeds and depths. Herein, for the first time, we report the application of frontal polymerization in the rehabilitation of underground pipes using a newly developed frontally curable epoxy-based resin (Trelleborg Self-Curing*). The neat resin is characterized for degree of cure, glass transition temperature, and mechanical properties via FTIR, DMA, and tensile tests, respectively. In a comprehensive way, the properties are benchmarked against commercially available acrylate (Trelleborg Light Cure*) and vinyl ester (Trelleborg Rapid Cure*) resins to evaluate their applicability for CIPP. The results show a higher glass transition temperature and final monomer conversion for the frontally cured resin, which cures significantly faster than the reference resins under the same irradiation conditions. In proof-of-concept trials, the newly developed resin successfully cures polymeric liners in a PVC host pipe with 100% water tightness and without losing its structural integrity. Results from ring stiffness tests for cured composite pipes additionally show that liners cured with Trelleborg Self-Curing* resin pass the minimum required Young's modulus for non-pressure drainage pipes as per ASTM F1216. Thus, frontally curable epoxy-based resins are a promising and competitive alternative to acrylates and vinyl esters in CIPP.     

Single-electron transfer living radical copolymerization of SWCNT-g-PMMA via graft from approach

The sidewall functionalization of single-walled carbon nanotubes (SWCNTs) was established by poly (methyl methacrylate) (PMMA) using controlled radical polymerization (CRP) method. A bromide functionalized SWCNT (SWCNT-Br) has been used as an initiator for the synthesis of SWCNT-graft-PMMA (SWCNT-g-PMMA). The efficiency of the sacrificial initiator (S) was monitored during the polymerization process. The obtained polymers possess a uniform distribution of molecular weight with a lower polydispersity index of 1.36. The SWCNTs-based initiator acts as an efficient medium for the controlled growth of polymer on the SWCNTs surfaces. The presence of bimodal gel permeation chromatographic (GPC) curve for the SWCNT-g-PMMA(S) obtained through sacrificial initiator (S) confirms uncontrolled behavior. However, the clear sharp peak for SWCNT-g-PMMA obtained without sacrificial initiator shows its well-controlled process of polymerization, which acts as a mimic to bone cement. The efficiency of the functionalization of SWCNT and the controlled formation of SWCNT-g-PMMA composites were characterized by TGA, Raman, TEM, NMR, XPS and dispersion measurements.