Synthesis of Hyperbranched Polymers and Its Effect on Water Vapor Permeability of Microfiber Synthetic Leather

A series of hyperbranched poly(amine-ester)polyols were synthesized by the polycondensation of N,N-diethylol-3-amine-methylpropionate(prepared by Michael addition reaction of methyl acrylate with diethanolamine)as an AB2-type monomer with trimethylol propane as the core moiety,proceeding in one-step procedure in the melt with p-toluenesulfonic acid as catalyst.The obtained monomer and polymers were characterized by FTIR and 1H-NMR spectroscopy.The solubility and surface activity in aqueous solution of the polymers were also examined.The gas permeability,water vapor permeability,and moisture absorption of microfiber synthetic leather treated by hyperbranched polymer were studied.The optimum conditions were that the dosage of dye and hyperbranched polymer was 5% and 10%,respectively.The water vapor permeability and moisture absorption of microfiber synthetic leather reached to 0.525 4 mg/(10 cm2·24 h)and 0.046 7 mg/(10 cm2·24 h).Compared with blank samples,they increased by 15% and 35%,respectively.However,the dosage of hyperbranched polymer has little influence on gas permeability of microfiber synthetic leather.SEM results show that the fiber of microfiber synthetic leather treated by hyperbranched polymer is incompact.

Controllable Synthesis of Externally Functional Dendronized Polymers

Through a controllable“reactivate””graft”synthetic route,two asymmetrical“Janus”dendronized polymers(DPs)were successfully synthesized.Dendrons were grafted to a linear polymer motherboard by a story-by-story constructionmethod.Due to the heterogenetic“Janus”structure,with orderly arranged chromophore moieties,the polymers demonstrated extremely large second-order nonlinear optical(NLO)coefficients and excellent NLO thermal stability.DP-4l and DP-6l had high d33 values of 232 and 227 pm/V,respectively,which reached the highest value reported so far for linear-based polymers containing simple azo-chromophore moieties.The controllable synthesis sheds light on the structure–property relationships of NLO polymers and other dendronized-structure functional polymers.

Synthesis and Properties of Photo-functional Hyperbranched Polymers

1 Results UV curing systems have been widely used in various industries such as coatings,printing inks,and photo-resists,because of their low volatile organic compound (VOC),excellent physical properties,and energy saving.Recently,these systems have also been applied to electronics and information technology fields such as display,CD,DVD,optical-fiber,and optical-device. In these curing systems,(meth)acrylate oligomers are mainly used due to their high photochemical reactivity. Recently,dendritic polyme...

Recent developments in the synthesis of sequence controlled polymers

The synthesis of sequence controlled polymers received increasing interest in polymer science. This mini review focuses on the principle and methods developed to control the sequence in polymer products from various polymerization mechanisms and processes. Typical examples are discussed to explicate the progress in this research field.

Controlled Synthesis of Polymers

Controlled synthesis is central to obtaining polymers with accurate structures and excellent performances.Recent research in the controlled synthesis of polymers has focused on optimizing monomers,initiation systems,and reaction conditions.The satisfactory sequence,topological structure,and dispersity have been achieved to satisfy the growing demand for functional polymers.This re-view summarizes the selection of monomers of various types and structures,the innovation of initiation systems,and the optimiza-tion of reaction conditions in the controlled synthesis of polymers and discusses their challenges and opportunities.

Organoboron chemistry towards controlled and precise polymer synthesis

Organoboron reagents have garnered considerable attention due to their distinct properties. In recent years, boronic acids and boronate esters have been important intermediates for cross-coupling reactions and other functional group construction and are often used to synthesize small organic molecules, drugs, and bioactive substances. In this feature article, we encapsulate the strategy of harnessing the unique properties of organoboron reagents to overcome challenges encountered in conventional polymer synthesis. We delve into the synthesis of boron-containing monomers and polymer materials, unraveling the unique attributes of these newfound polymers while offering innovative insights into their application within recyclable or reprocessable materials. We develop organoboron-based photocatalysts, employing their inner-sphere electron transfer(ISET) mechanisms to initiate controlled radical polymerization. We utilize alkylborane to initiate controlled radical polymerization and further designed B-alkylcatecholboranes to prepare ultra-high molecular weight polymers. Notably, we also propose a liquid-phase synthesis method based on organoboron tags and apply it to the precise synthesis of sequence-controlled conjugated polymers.These advancements open up new frontiers in the realm of polymer science, and the versatility and potential of organoboron reagents in polymer synthesis continue to inspire exciting research endeavors.

Knitted Microporous Polymers as Efficient Adsorbents for Wastewater Treatment: Effects of Skeleton Structure and Pore Distribution

Hyper-cross-linked microporous organic polymers(MOP) with controlled skeleton structure and pore distribution were prepared by Friedel-Crafts alkylation reaction. The hyper-cross-linked polymers(HCPs) produced by knitting aromatic functional groups posses the typical micro-and meso-porous composite structure and specific surface areas of up to 957 m^2·g^(-1). The obtained materials were evaluated as adsorbents for methylene blue(MB) and subjected to several batch adsorption tests to investigate the effects of adsorbent dosage, concentration of MB, temperature, and pH on MB removal. The maximum adsorbed capacity(q_m) of KAPs-Ph(381 mg·g^(-1), knitted using benzene) exceeded those of less mesoporous KAPs-PhPh_3(310 mg·g^(-1) knitted using 1,3,5-triphenylbenzene) and chloromethyl polystyrene resin(58 mg·g^(-1)). Moreover, KAPs-Ph could be regenerated by Soxhlet extraction with ethanol and reused for up to 15 times with minimal loss of adsorption capacity. The results illustrate that adsorption performance can be improved by controlling the pore structure of the adsorbing materials, and KAPs-Ph has a potential application values for the industrial removal of organic dyes from wastewater.

Synthesis of Glutathione Imprinted Polymer Particles via Controlled Living Radical Precipitation Polymerization

A general protocol was described for fabricating uniform molecularly imprinted polymer （MIP） particles via controlled living radical precipitation polymerization at ambient temperature. By adopting glutathione as model template, benzyl dithiocarbamate as iniferter agent, 4-vinylpyridine as monomer, and ethylene glycol dimethacrylate as cross-linker, it is demonstrated that the polymerization parameters including the iniferter concentration, monomer loading and molar ratio of cross-linker to functional monomer have profound effect on the final particle size and recognition property of the MIP particles. The batch static binding experiments were carried out to estimate the adsorption kinetics, adsorption isotherms and selective recognition of the MIP particles. The adsorption behavior followed the pseudo-second order kinetic model, revealing that the process was chemically carried out. Two adsorption isotherm models were applied to analyze equilibrium data, obtaining the best description by Langmuir isotherm model. In addition, the MIP particles also could selectively recognize glutathione over similar analogs, indicating the possibility for the separation and enrichment of the template from complicated matrices.

Research progress in the living/controlled polymerization of(meth)acrylate monomers by Lewis pair

Lewis pair polymerization(LPP)has demonstrated its unique advantages,such as high activity,high stability,and adjustable variability,towards the polymerization of(meth)acrylate monomers in comparison with the other polymerization techniques.The combination of Lewis acid(LA)and Lewis base(LB)to construct Lewis pairs(LPs)with appropriate Lewis basicity,Lewis acidity,and steric effects would significantly impact the polymerization process,including chain initiation,propagation,termination and chain transfer reaction,as well as polymerization manner of monomers.In this feature article,we briefly review recent progress made by our research group towards the living/controlled polymerization of(meth)acrylate monomers,which were accomplished by a series of newly designed LPs,including monofunctional LPs,dual-initiating LPs and intramolecular tethered trifunctional LP.This article is divided into three parts:(1)the development of monofunctional living/controlled LP polymerization system;(2)the design and preparation of dual-initiating LPs in synthesizing thermoplastic elastomers;(3)the application of intramolecular trifunctional LP to the synthesis of cyclic polymers.These developed LPPs have demonstrated their powerful capability in precise control over the molecular weight,molecular weight distribution,and monomer sequence as well as the topology of polymers.This review will serve as a good resource or guideline for researchers currently working in the area of LPP and for those who are interested in synthesizing new materials by LPP.

“Controlled” and “Living” Cationic Polymerizations:Another Way Towards Well Defined Polymer Architectures and Materials

1 Results No doubt that one of the major breakthroughs in polymer chemistry was the discovery and the progressive implementation of the "living" and "controlled" polymerizations.These now widely used techniques allow not only to control with an extreme precision the molar masses and their distributions but also to synthesise easily a broad variety of architectures from block and graft copolymers,miktoarms stars,to polymer brushes,hyperbranched polymers,dendrimers,etc....They opened an immense domain of ...

Synthesis of polystyrene with high melting temperature through BDE/CuCI catalyzed polymerization

No matter what the polymerization manner was, polystyrene with unique highT m (T m = 170–285°C) was obtained through polymerization of styrene if the amount of BDE/CuCl catalyst was highly increased (mol ratio: St:CuCl = 25:1-2.5:1). Partial crystallinity of the PSt was observed by characterizations of X-ray diffraction and DSC. Spectra of1H-NMR and13C-NMR showed that syndiotactic structure contained in the obtained PSt was 5% more than that in aPSt (atactic polystyrene). According to the proposed “coordinated radical cage” mechanism, the coordinated state between radical and catalyst center metal Cu should be more closely packed with increasing the BDE/CuCl catalyst amount, which was induced to partial stereospecific polymerization in the coordinated radical polymerization of St.

Controlled free radical polymerization of styrene initiated from the alkoxyamine-functionalized silicon surface

We describe a new method of fabricating a brush-like polystyrene layer anchored on the surface of the silicon substrate, which involves three steps, namely (i) the attachment of 3-methacryloxypropyltrimethoxysilane onto the silicon surface; (ii) the reaction of vinyl moiety at another extremity of the anchored 3-methacryloxypropyltrimethoxysilane to 4-Hydroxyl-2, 2, 6, 6-tetramethyl-1-piperidinyloxy (HTEMPO?) catalyzed by azobisisobutyronitrile (AIBN); (iii) living free radical grafting polymerization of styrene in the presence of HTEMPO?. The controllable living free radical polymerization permits accurate control of both the molecular weight and the polydispersity. X-photoelectron spectroscopy measurement proved that the alkoxyamine initiator layer forms on the silicon surface. XPS and Ellipsometry measurements showed that the poly-styrene chains were covalently anchored onto the silicon surface. The thickness of the grafted polymer layer can be accurately manipulated by altering the polymerization time. The new method allows synthesizing random copolymer and block copolymers by the sequential growth of monomers from the substrate surface.

Lewis pairs polymerization of polar vinyl monomers

The globally increasing demands for polymer materials stimulate the significantly intense attention focused on the Lewis pair polymerization(LPP) of various polar vinyl monomers catalyzed by Lewis pairs(LPs) composed of Lewis acid(LA) and Lewis base(LB). According to the degree of interaction between LA and LB, LPs could be divided into classical Lewis adduct(CLA), interacting Lewis pair(ILP) and frustrated Lewis pair(FLP). Regulation of the Lewis basicity, Lewis acidity, and steric effects of these LPs has a significant impact on the polymer chain initiation, propagation and termination as well as chain transfer reaction during polymerization. Compared with other polymerization strategies, LPP has shown several unique advantages towards the polymerization of polar vinyl monomers such as high activity, control or livingness, mild conditions, and complete chemo-or regioselectivity. We will comprehensively review the recent advances achieved in the LPP of polar vinyl monomers according to the classification of the employed LPs based on different LAs, by highlighting the key polymerization results, polymerization mechanisms as well as the currently unmet challenges and the future research directions of LPP chemistry.

超支化聚合物在生物医学材料中应用研究进展

超支化聚合物(HBPs)具有高活性功能端基,便于修饰改性,能够设计合成结构明确且具有特定功能的高分子材料,在生物医学领域具有潜在应用价值。可控/活性自由基聚合(CLRP)技术在聚合物合成领域受到广泛关注,并将其运用到医疗产品、纳米材料、航天器件等众多领域中。近年来,在合成具有生物可降解和生物相容性的HBPs的发展方面已取得了诸多进展,对HBPs在生物医学领域的最新研究进展进行了总结,重点介绍了HBPs在药物传递、基因转染、组织工程、抗菌/防污材料、生物医学成像等方面的应用,并对HBPs的发展前景进行了展望。

星形聚合物的研究与应用进展

回顾了结构性能独特且应用颇为广泛的非线性星形聚合物研究现状;介绍了星形聚合物的特点、应用,以及通过活性聚合制备星形聚合物的不同合成方法,比较了各种合成方法的优缺点;综述了星形聚合物用作研究聚合物的支化模型、简化树形聚合物复杂的支化结构、获得聚合物支化信息的研究进展。

超支化聚合物合成方法与应用研究进展

介绍了超支化聚合物的合成方法:缩聚法、活性聚合法、离子聚合法、开环聚合、可逆加成链转移聚合法和自缩合基团转移聚合等新型合成方法;阐述了目前超支化聚合物在涂料、共混改性、聚合物膜、药物、纳米复合材料、聚电解质、超支化液晶等方面的应用进展;展望了该类聚合物今后的研究发展方向。

结构可控含氟共聚物的合成及其应用研究新进展

近年来,含氟聚合物以其优异的耐热性、耐氧化性、耐候性、耐腐蚀性以及低介电常数、低表面能等特点,在疏水材料、抗污材料、表面活性剂、造影剂等领域具有广泛的应用前景,受到研究者的密切关注,各种拓扑结构的含氟共聚物被设计合成出来并在相关领域得到应用。本文首先简要介绍了含氟聚合物的性质和研究现状,然后详细叙述了可逆加成-断裂链转移聚合(RAFT)、原子转移自由基聚合(ATRP)、碘转移自由基聚合(ITP)、单电子转移活性聚合(SET-LRP)、氮氧稳定自由基聚合(NMP)以及活性阴离子聚合(LAP)等聚合方法在结构可控含氟共聚物合成中的研究新进展,并对其聚合机理、优缺点以及所得共聚物的性质和应用进行了总结,最后对结构可控含氟共聚物的设计、合成及实际应用前景进行了展望,提出发展绿色环保功能性含氟聚合物将是未来的主要研究热点。

活性聚合在星形聚合物合成中的应用

星形聚合物在近年来发展迅速,其结构、形态、合成方法与功能性是高分子科学的研究热点。本文主要从活性离子聚合手段与活性自由基聚合手段两方面对星形聚合物的合成方法进行分类,依托星形聚合物的单体选择、星形臂的特性以及整体功能性进行系统阐述,介绍近年来星形聚合物合成方法、形貌控制以及功能性质的最新研究进展。本文结合现阶段最新的研究成果,对星形聚合物在功能与应用之间的联系进行了展望与预测。

智能涂料制备方法探索与应用

智能涂料是近几年在新型特种功能涂料基础上发展起来的。本文主要对其制备方法、类别及应用进行了详细论述。智能涂料的制备可以从聚合物膜、颜料及制作工艺等方面入手,其中创造具有"开关"性质且依赖于外部环境的刺激/响应聚合物膜的设计最为重要,它关系到膜的形成和膜表面性质,是涂料智能化的关键所在。在合成方法上,活性/可控自由基聚合技术、表面接枝技术和层层自组装工艺等已经应用于智能聚合物膜的制备;另外,纳米技术应用于涂料,也是智能涂料另一制备方法,因其某些超强性能而被视为智能涂料的初级阶段。目前,整个智能涂料的发展还基本处于以纳米技术为基础的初级阶段,其中进展较大的品种有:自清洁、抗菌、防腐、隐身、发光、磁性等对光、电、磁、温、湿、压敏感的涂料,而以智能聚合物膜为基础的高层次智能涂料还基本处于研究开发阶段。

活性聚合法合成含能聚合物的研究进展

综述了活性聚合法合成含能聚合物的研究发展状况,主要介绍了活性聚合法合成含能聚合物的反应机理及性质。指出活性阳离子聚合法仍是一段时间内研究的重点,并对其今后的研究进行了展望。