螺环原碳酸酯类膨胀单体的合成

膨胀单体和膨胀聚合反应的特点是在聚合过程中能产生体积膨胀 ,可以用于环氧树脂粘合剂的改性研究。膨胀单体中很重要的一类是螺环原碳酸酯。本文综述此类单体的合成方法。     

一种螺环原碳酸酯膨胀单体的合成及其与环氧树脂热固化

经两步法合成了一种螺环原碳酸酯类膨胀单体,该单体在固化剂三氟化硼乙胺催化作用下,能进行阳离子双开环聚合反应,并讨论了该单体聚合反应机理。采用差示扫描量热(DSC)跟踪环氧树脂及其被膨胀单体改性后的固化反应过程,发现纯环氧树脂存在2个固化反应放热峰,而改性树脂仅有一个反应放热峰。结果表明:膨胀单体和环氧树脂进行了开环共聚反应,膨胀单体的加入能提高环氧基团的转化率。     

螺环原碳酸酯/环氧树脂体系固化反应动力学

采用示差扫描量热法(DSC)对螺环原碳酸酯膨胀单体(SOC)/双酚A型环氧树脂(EP)体系的固化行为、放热峰进行了分析;并用Kissinger方程和Crane方程求得体系表观活化能、表观反应频率因子、反应级数等固化反应过程动力学参数,结果表明:螺环原碳酸酯膨胀单体的加入,体系的表观活化能和表观反应频率因子增加,反应级数保持不变,而反应速率急剧下降。此外,利用外延法对体系起始固化温度、恒温固化温度以及后处理温度进行初步探讨,为固化工艺的确定提供了依据。     

螺环二醇改性PET共聚酯的合成及性能

为了扩大聚对苯二甲酸乙二醇酯（PET）的应用范围,常通过引入第三单体来改变其性能。本研究以螺环二醇（SPG）为原料,采用酯交换法熔融缩聚合成了一系列不同单体含量的共聚酯。采用超高效聚合物色谱-多角度激光光散射仪（APC-MALLS）联用分析了共聚酯的分子量与分子量分布,利用核磁氢谱（¹H NMR）、傅里叶红外光谱（FTIR）研究了共聚酯的化学结构,同时采用差示扫描量热仪（DSC）、热重分析仪（TGA）和X射线衍射仪（XRD）研究了共聚酯的热性能以及结晶性能,测试了共聚酯的拉伸性能。结果表明,成功合成了符合纤维级聚酯数均分子量（M_n）和重均分子量（M_w）要求的共聚酯,分子量分布较窄,随着第三单体含量的增加,玻璃化转变温度从77℃提升至85℃,而熔融温度从255℃降低至222℃,热分解温度无明显变化,结晶性能下降。     

一种双环原酸酯的合成研究

由原甲酸三乙酯与季戊四醇为原料制备了一种双环原酸酯 4-羟甲基 -2 ,6,7-三氧杂二环( 2 ,2 ,2 )辛烷 ,并提供了一条简单可行的合成途径。     

聚丙烯酸酯吸油膨胀橡胶的合成及性能研究

以丙烯酸乙酯（EA）、丙烯酸十二酯（LA）和甲基丙烯酸羟乙酯（HEMA）为单体,采用乳液聚合的方法制备了含羟基的丙烯酸酯共聚物,塑炼后与多缩水甘油酯交联剂和白炭黑进行混炼、硫化,制得吸油膨胀橡胶（OSR）。研究了单体配比、乳化剂用量、交联剂用量对OSR吸油膨胀性能和力学性能的影响,并研究了吸油时间对OSR吸油膨胀性能的影响。结果表明：随着LA单体比例的增加,OSR的硬度和拉伸强度降低,吸油膨胀率增大。随着交联剂用量的增加,OSR的硬度、拉伸强度和断裂伸长率增大,吸油膨胀率随着交联剂用量的增加呈先升后降的趋势。随着吸油时间的增加,OSR的吸油膨胀率增大,在10h后吸油膨胀率几乎不变。     

阳离子染料可染PTT的性能研究

研究了聚对苯二甲酸丙二醇酯(PTT)及阳离子染料可染PTT(改性PTT)的性能。结果表明:随着第三单体间苯二甲酸丙二醇酯-5-磺酸钠(SIPP)加入量的增加,改性PTT的玻璃化转变温度、结晶温度逐渐升高,熔点呈减小趋势,而SIPP的加入对PTT的热降解影响不大;改性PTT的表观粘度随剪切速率的增加而减小,属于非牛顿流体,但其流变性变差;加入第四单体聚乙二醇(PEG)对改性PTT的流变性能有所改善;随着第三单体添加量的增加,改性PTT纤维对阳离子染料的上染率增大,加入第四单体后,上染速率及最终上染率提高。     

氯化螺环磷酸酯的合成

氯化螺环磷酸酯是一种新型膨胀型阻燃剂,同时它也是舍成许多高效低毒无卤膨胀型阻燃荆的中间体.以三氯氧磷、季戊四醇为原料,三氯化铝为催化剂,甲苯/乙腈混合物为溶剂,通过酯化反应合成氯化螺环磷酸酯,并研究影响反应的因素,得出最佳工艺条件,采用元素分析和红外鉴定产品的化学结构.     

乙烯基螺环原酯（VS）和马来酸酐（MA）的交替光共聚

乙烯基螺环原酯（ＶＳ）－２－亚甲基－１，４，６－三氧螺（４，４）壬烷和马来酸酐（ＭＡ）的光聚合反应，通过形成电荷转移络合物反应中间体，按烯类加聚方式生成线性交替共聚物。在温和条件下，ＶＳ和ＭＡ的光聚合反应仅在自由基光引发剂存在时才发生，聚合速度取决于溶剂极性和两种单体的投料比。而共聚物的组成与单体投料比无关，保持等摩尔比值。采用ＵＶ吸收光谱进一步研究了ＶＳ和ＭＡ等摩尔ＣＴ络合物的形成，并测定了它们     

甲基丙烯酸甲酸与醋酸乙烯的本体共聚和溶液共聚

在各种反应条件下进行了甲基丙烯酸甲酯和醋酸乙烯的批量本体共聚和在甲苯中的溶液共聚，达到了高度的单体转化率。另外，以终端模型动力学（Magu-Lewis）为基础，通过多变模型方法的差错进行了低转化本体实验来确定单体的竞聚率。从先前研究出的高转化数据和低转化数据由共聚组成（Meyer-Lowry）的积分方程得出竞聚率分别为0．0102（γVAc）和27．465（γMMA)。通过高转化率实验，研究了各种因素对反应速率、渐增的共聚物组成、数均分子量、重均分子量以及分子量分布的影响。这些因素包括单体组成、引发剂浓度、温度、溶液浓度和N－十二硫醇链转移剂的加入。借助单体竞聚率的巨大差异对这些因素进行了检测。     

Catalytic double ring-opening polyaddition of spiro orthoester with acid chloride for shrinkage-controlled molding

In order to develop a casting resin for precision molding, a curing method without shrinkage during the polymerization was achieved by the double ring-opening addition reaction of spiro orthoester (SOE) and acid chloride using cationic catalysts. Tetraphenylphosphonium halides (TPPXs) were found to be effective catalysts for the reaction. The catalytic reaction of SOE with acid chloride proceeded even at 25 °C to give the corresponding adduct. Polyaddition of a bifunctional SOE-XII with trifunctional 1,3,5-pentanetricarbonyl trichloride gave a cured material at 30 °C in the presence of tetraphenylphosphonium bromide (TPPB) of 1 mol%, accompanied by a negligible shrinkage of 0.21%. Gelation time was shortened with increase in the amount of catalyst and reaction temperature in the curing process. The obtained products were crosslinked copolymers that showed variable mechanical properties dependent on the curing temperature and monomer structure. This is the first demonstration of shrinkage-controlled molding in the absence of heating or cooling process.     

Synthesis of polymeric flame retardants containing phosphorus‐nitrogen‐bromide and their application in acrylonitrile‐butadiene‐styrene

A series of polymeric flame retardants (PFRs) containing phosphorus‐nitrogen‐bromide were synthesized from spirocyclic pentaerythritol bisphosphorate disphosphoryl chloride (SPDPC), 2‐methoxyl‐4,6‐dichloro‐1,3,5‐triazine (MDCT), and tetrabromobisphenol A (TBBPA). The influence of monomer ratio on their thermal stability was investigated by adjusting the proportion of SPDPC/MDCT (mol/mol) from 80/20 to 20/80. The flammability properties of the PFRs blended with ABS were evaluated using LOI and UL‐94 vertical test. The structures of the flame retardants were characterized by means of Fourier transform infrared spectra (FTIR) and proton nuclear magnetic resonance spectroscopy (¹H‐NMR). The results show that the initial temperature of decomposition is 274°C and with 35% charring residue at 500°C when the ratio of SPDPC/MDCT is 50/50. V‐0 ratings in the UL‐94 vertical test were achieved at 20–30% loading of PFRs, when LOI values reached at least 26.9%. The flame retardancy is strongly dependent on the ratio of P, N, and Br. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

甲基丙烯酰胺丙基三甲基氯化铵单体、聚合物合成及应用研究进展

甲基丙烯酰胺丙基三甲基氯化铵(MAPTAC)是一种具有耐酸碱耐温优点的季铵盐阳离子单体,其聚合物具有良好的应用前景.首先,该文分别介绍了MAPTAC单体及其聚合物的合成研究进展;其次,分别概述了MAPTAC聚合物在日化用品、石油开采、水处理、医学等领域的应用研究进展.最后,在提高MAPTAC聚合物相对分子质量、缩小MA...     

Photosensitive 2,5-distyrylpyrazine particles produced from rapid expansion of supercritical solutions

Solvent-free, photoreactive particles of 2,5-distyrylpyrazine (DSP) monomer were developed by rapid precipitation from an expanding supercritical chlorodifluoromethane solution. DSP polymer particles were produced by solid-state photopolymerization. DSP particles below a critical diameter of about 0.5 μm were found to be mechanically stable and did not fragment upon photopolymerization. The rate of DSP photopolymerization was shown to be size-sensitive. Nano-scale particles demonstrated superior photoreactivity in the solid state in comparison to micro-scale crystals. UV spectra of DSP at different degrees of conversion were investigated and the extinction coefficients were calculated for the DSP monomer and polymer in sulfuric acid.     

Solid state reaction of bifunctional bicyclo orthoesters and carboxylic acids and their metal adhesive properties

Five kinds of novel bifunctional bicyclo orthoesters (BOEs) were synthesized and copolymerized with multi-functional carboxylic acids, having plural carboxyl and hydroxyl groups, to develop functional materials usable as non-volatile adhesives. In a solid-state reaction of BOEs with the carboxylic acids, mechanical mixing converted the BOE moiety to a corresponding hydrolyzed form via ring-opening and isomerization reactions. The solid-state reaction, requiring moisture and mechanical stress, was accelerated by the higher reactivity given by the α-hydroxyl group in the acids. Superior adhesive bonding to the Ni-Cr alloyed metal substrate was achieved via a heating process at 150 °C, and high average tensile strengths of ∼80 MPa were obtained by using mixtures of BOEs and dl-tartaric acid. This highly adhesive property was achieved not only by polycondensation of BOE-hydrolyzates and the carboxylic acids, but also by polyaddition of BOEs and the carboxylic acids.     

聚氨酯缔合型增稠剂(I系列)的研制与应用

利用异佛尔酮二异氰酸酯(IPDI)与一定相对分子质量的聚乙二醇进行本体聚合得到一定规格的聚氨酯单体,同时加入扩链剂和封端剂进行改性,最后与溶剂和助溶剂进行复配,制成缔合型聚氨酯增稠剂成品。对合成过程中的温度、催化剂、加料次序及滴加速率等条件进行了研究。     

高吸水性树脂超声波法制备研究进展及趋势

综述了超声波法制备高吸水树脂研究进展,包括超声波法制备合成聚合物系列高吸水树脂、超声波法制备天然多糖交联型高吸水树脂、超声波法制备接枝天然多糖型高吸水树脂等。最后指出了超声波法制备高吸水树脂研究需要加强的几个方向:即加强超声波法制备各种类型高吸水树脂的实验研究;加强超声辐射产生设备的革新研究;降低成本,扩大应用领域。     

HF-unterstützte Synthese von Orthoestern und Oxazolinen. [1]

A convenient method is reported to generate the ortho-pivalic acid esters 5 and 7 from meso-erythrit 3 ) and D -mannitol ( 6 ), respectively, using a HF-supported procedure. Furthermore, the α-D -glucopyrano[1,2-d]-2-oxazolines 9 and 10 were prepared from starch and nitriles (pivalonitrile and benzonitrile) by a Ritter-type reaction in anhydrous hydrogen fluoride. The separation of the products 5 , 7 , 9 , and 10 was possible by quenching of their HF-solutions with triethylamine. The structure of the orthoester 7 and the oxazoline 10 was confirmed by X-ray analyses.     

Tailoring bulk and surface grafting of poly(acrylic acid) in electron-irradiated PVDF

Endowing conventional hydrophobic poly(vinylidene fluoride) (PVDF) films with hydrophilic properties was conducted using electron beam irradiation. Grafting of acrylic acid (AA) in/onto pre-irradiated PVDF films was investigated. Reaction parameters, monomer concentration and inhibitor concentration were examined. Radiation grafted films (PVDF-g-PAA) were synthesized with various grafting yields ranging from 12 to 130 wt % in presence of Mohr's salt (25 wt %). Below 80 wt % of monomer concentration, the degree of swelling was found to increase with the grafting yield. The PAA was arranged randomly in all PVDF matrix (grafting through). Above 80 wt % of monomer concentration, the PAA was grafted only onto the surface of PVDF films leading to a highly dense layer of PAA. Grafting through or surface grafting processes were achieved by varying the water fraction in the initial monomer solution. Water molecule acts not only as a carrier for the monomer but also as a plasticizer expanding the film in the three dimensions. Evidences of grafting through and surface grafting were produced using FTIR in ATR mode, SEM coupled to X-ray detection and XPS. An accurate quantification of AA units was possible up to the micromole via a Cu²⁺–EDTA complex analyzed by UV–vis spectroscopy.     

Bicyclo‐orthoester as a low‐shrinkage additive in cationic UV curing

A commercially available bicyclo‐orthoester (BOE) was used as low‐shrinkage additive for cationic UV curing of epoxy resins. A high reactivity of BOE by ring‐opening homopolymerization has been observed under cationic UV curing conditions. The BOE and trimethylolpropane triglycidyl ether monomers are compatible and give rise to a cured copolymeric network, under UV irradiation, with a flexibilization increase by increasing the BOE content in the photocurable formulation. Shrinkage after photopolymerization shows a linear reduction by increasing the BOE content in the photocurable formulation; a volume expansion upon polymerization is reached in the presence of 50 wt% of the additive. Copyright © 2007 Society of Chemical Industry