超临界二氧化碳中N-异丙基丙烯酰胺与二乙二醇二甲基丙烯酸酯的交联聚合

采用超临界二氧化碳（scCO2）沉淀聚合法,在不添加高分子表面活性剂及共溶剂的前提下,以AIBN为引发剂,二乙二醇二甲基丙烯酸酯为交联剂,成功制备了交联的聚（N-异丙基丙烯酰胺）温度敏感型微凝胶;通过扫描电镜（SEM）、差示扫描量热分析（DSC）等方法对聚合物的微观形貌进行了表征,测定了微凝胶的相转变温度,同时也考察了...     

自由基聚合法制备聚乙二醇双丙烯酸酯水凝胶

以过二硫酸胺(APS)/四甲基乙二胺(TMEDA)氧化-还原体系为引发体系,通过活性自由基溶液聚合法制备了交联网状聚乙二醇双丙烯酸酯(PEGDA)共聚物水凝胶支架,探讨了APS/TMEDA的引发聚合机理。研究结果表明,单体分子量越大,凝胶化时间越短,凝胶化时间随着PEGDA单体浓度的增大、温度的升高和加速剂用量的增大而减小。研究了不同单体浓度对水凝胶溶胀度及力学性能的影响,结果表明,单体溶液浓度越大,水凝胶的平衡溶胀率越小、压缩模量越强。     

1,3-戊二烯-1-戊烯阳离子共聚反应

研究了ＡｌＣｌ３引发的１,３－戊二烯（ＰＤ）－１－戊（ＰＩ）阳离子共聚反应。在正已烷作介质的ＰＤ阳离子聚合体系中加入ＰＩ可抑制凝胶（交联聚合物）的生成,同时使聚合物总产率下降。随共聚单体中ＰＩ含量的增加,聚合物分子量先呈现上升,并在达到极大值后逐渐下降。在甲苯介质中ＡｌＣｌ３引发的ＰＤ阳离子聚合体系中加入ＰＩ使得聚合物产率呈现下降趋势,聚合物分子量仍随共聚单体ＰＩ含量的增加先呈现上升并在达到极大值     

高固体份丙烯酸汽车面漆

1.低分子量丙烯酸树酯的合成及性能含有二种或三种单体,如α-甲基苯乙烯(MS)、苯乙烯、丙烯酸、丙烯酸丁酯,2-羟乙基丙烯酸酯,2-羟丙基丙烯酸酯及新戊二醇单丙烯酸酯的低分子量聚合物可在150℃左右用溶液聚合或本体聚合的方法制备,采用过氧化二异丙苯作引发剂(2.5g/mol单体);不同剂量的3-巯基丙酸(MPA)作链转移剂。聚合反应后,用1,2-环氧丙烷或2,2-二甲基辛酸缩水甘油酯(Cardura E)将羧基(来自丙烯酸和MPA)转化为可固化的羟     

马来酸酐-苯乙烯多单体熔融接枝EVA的研究

用单螺杆挤出机研究了马来酸酐（MAH）－苯乙烯（St)多组分单体熔融接枝EVA的反应,考察了温度、引发剂用量、MAH和St用量对接枝率及凝胶率的影响。结果表明：MAH接枝率随DCP用量、St用量的增加、反应温度的降低有最大值;当EVA／MAH／St/DCP质量比为100：4：4：0.4时,MAH接枝率最大,而凝胶率最小;以St作共单体能够显著提高MAH的接枝率,抑制体系交联;St和MAH的相互作用和共聚反应生成的SMA共聚物在接枝反应中起重要作用。     

pH-GSH双敏感型P(mPEGMA-DEAM-SS)水凝胶的溶胀动力学

以甲氧基聚乙二醇甲基丙烯酸酯(m PEGMA)、甲基丙烯酸-N-N-二乙氨基乙酯(DEAM)为单体,2,2'-二硫二乙醇的二甲基丙烯酸酯(SS)为交联剂,采用自由基交联共聚法制备了具有p H-GSH双敏感性的P(m PEGMA-DEAM-SS)水凝胶。研究了溶剂对凝胶溶胀性能的影响,并初步研究了在不同介质中水凝胶的溶胀动力学。结果表明,以N-N-二甲基甲酰胺(DMF)为溶剂时,可获得良好p H响应能力的水凝胶;水凝胶的溶胀过程表现出良好的p H-GSH双敏感性,该水凝胶的扩散行为在酸性介质中符合non-Fickian模型,而在中性介质则符合Fickian模型;在10 mmol/L GSH条件下,水凝胶溶胀率上升了4倍多,其扩散亦为non-Fickian扩散模式。     

光聚合法合成印刷电路板保护涂料的研究

采用光聚合法合成丙烯酸酯预聚物,然后在预聚物中加入交联单体、复合光引发剂、活性胺等制备印刷电路板(PCB)保护涂料。研究了本体光聚合的最佳反应时间,讨论了在光聚合条件下预聚物、功能单体、交联剂等对涂膜性能的影响。对光聚合产物进行了热重分析、红外光谱测试和表征。结果表明,在紫外光照射下的最佳预聚合反应时间为60s,单体转化率可达60%;当构成光敏预聚物的光聚合单体丙烯酸丁酯(BA)∶丙烯酸异冰片酯(IBOA)∶丙烯酸(AA)=6∶4∶1(wt,质量),后期加入的交联单体为18%(wt,质量分数,下同),复合光引发剂为3%,活性胺为2%时,涂料固化后各项性能最佳。     

DM-AM、TM-AM共聚反应竞聚率EI

通过阳离子单体：二甲基二烯丙基氯化铵（ＤＭ）、三甲基烯丙基氯化铵（ＴＭ），分别与丙烯酰胺（ＡＭ），用Ｎａ２Ｓ２Ｏ８－Ｎａ２ＳＯ３引发剂引发，在水溶液中不同单体摩尔比条件下的自由基共聚合，分别用直线交点法、Ｆｉｎｅｍａｎ－Ｒｏｓｓ法和Ｍａｙｏ－Ｌｅｗｉｓ积分法测定了两种阳离子共聚物ＤＭ－ＡＭ、ＴＭ－ＡＭ共聚反应单体竞聚率。     

有机过氧化物交联间规聚丙烯研究

用DSC对三羟甲基丙烷三甲基丙烯酸酯（TMPTMA）存在下的间规聚丙烯过氧化物交联进行了研究。根据交联过程中反应热焓的变化结合交联前后凝胶含量的结果确定了工艺条件。单独使用过氧化物或多官能团单体均难以使sPP交联,在sPP/TMPTMA/DCP交联体系中,多官能团单体聚合后在sPP基体中形成的中间产物通过捕捉sPP大分子自由基形成了交联结构。随DCP和TMPTMA用量的增加,交联程度增大,但高温下长长时间反应会导致sPP的降解反应加剧,凝胶含量下降。     

两亲水溶性阳离子聚电解质研究1.聚(苯乙烯-丙烯酰胺甲基二羟乙基苄基氯化铵)丙烯酰胺)的合成和表征

以ＡＩＢＮ为引发剂,苯乙烯与丙烯酰胺在１,４－二氧六环溶剂中共聚,得到Ｐ（Ｓｔ－Ａｍ）,通过Ｍａｎｎｉｃｈ反应,甲醛与二乙胺反应生成Ｎ,Ｎ－二羟乙基甲醇胺,然后与Ｐ（Ｓｔ－Ａｍ）缩合,最后以苄氯为季铵化试剂,与上述反应产物进行季铵化反应,得到阳离子聚。     

水显影光固化材料的制备及其各组分对感光性能的影响

利用热塑性酚醛环氧树脂的环氧基，依次用丙烯酸及叔胺盐进行开环反应，合成了水溶性丙烯酸酯类感光高分子，将其配制成水显影光固化材料，并研究了叔胺盐的种类，不同光引发剂和光谱效剂以及稀释性单体对其感光性能的影响。     

Emission modeling of styrene from vinyl ester resins with low hazardous air pollutant contents

Styrene is a commonly used co-monomer in vinyl ester (VE) resins, which acts as a reactive diluent and is required in most liquid molding fabrication methods to reduce viscosity and improve overall resin performance. Resins containing low hazardous air pollutant contents have been developed to reduce the styrene emissions during composite fabrication. VE monomers with a bimodal molecular weight distribution have been used to effectively decrease the amount of styrene in the system while maintaining low resin viscosities. Fatty acid vinyl ester (FAVE) resins partially replace styrene with non-volatile fatty acid monomers to reduce styrene emissions. The emissions from bimodal and FAVE resins were measured as a function of time and various parameters, including styrene content, VE molecular weight, and fatty acid monomer content and chain length. The initial emission rate from VE resins is only dependent on styrene content for constant evaporation geometry. Furthermore, the evaporation rate constant was the same regardless of VE molecular weight, styrene content, or the use of co-reactive diluent (MFA monomers). The diffusivity was not dependent on the styrene content in the resin, but decreased linearly as the VE molecular weight increased because of a corresponding increase in the resin viscosity. The diffusivity also increased as the content of MFA increased because of a decrease in the resin viscosity with high MFA content at high emission time. Furthermore, the emission profiles were accurately modeled using a modified version of 1D diffusion through a planar sheet that accounts for the depth change as a function of styrene evaporation. Overall, the model predicted emission profiles similar to the experimentally measured profiles as a function of time for various styrene contents, VE molecular weights, and fatty acid monomer contents.     

Mechanical strength of urethane-based visible-light-cured resins

In experimental urethane-based visible-light-cured(VLC) resins containing a diluent monomer, a lower value of activation energy for polymerization than in bis-GMA-based VLC resin was obtained. A greater increased diametral tensile strength and slightly larger compression strength were observed. The diluent monomer in the urethane-based VLC resins gives an increase of strength, associated with lower activation energy for polymerization, compared with the bis-GMA-based resin.     

Use of Differential Scanning Calorimetry (DSC) in the Characterization of EPDM/PP Blends

New polyolefinic thermoplastic elastomers based on the ethylene–propylene-diene monomer (EPDM) and polypropylene (PP) containing an EPDM elastomer of the last generation (Nordel NDR 47130), obtained by polymerization in the gaseous phase with metallocene catalysis, were prepared and characterized. The melting and crystallization behavior of these blends was investigated by differential scanning calorimetry. It is observed that the melting temperature, crystallization temperature, and crystallinity degree increase with an increase of PP loading. The influence of the blend composition on the physico-mechanical characteristics was discussed using statistical processing of the experimental data. Two compatibilizing procedures were utilized to improve the physico-mechanical characteristics of the samples: an addition method using different compatibilizing agents and dynamical vulcanization with three types of crosslinking systems. Significant improvements of the tensile strength and tear strength were noted by dynamic crosslinking, and the best results were obtained using a crosslinking system based on phenolic resin and tin chloride.     

含氟丙烯酸树脂的合成及性能研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主要单体,甲基丙烯酸全氟烷基酯(FMA)为合氟单体,甲基丙烯酸羟基乙酯(HEMA)为交联单体,采用溶液聚合法合成含氟丙烯酸树脂,并与固化剂六甲撑二异氰酸酯(HDI)三聚体固化成膜.研究了软硬单体配比、羟值、聚合温度、氟单体含量及添加方式等因素对树脂粘度、分子量及其分布以及涂膜的疏水性、硬度、附着力和耐热性的影响.结果表明,在m(BA):m(MMA)=6:4、羟值为64.8mg/g、氟单体用量为3%且采用后期添加、反应温度为85℃的条件下制得了含氟丙烯酸树脂,其分子量Mn=26980,分布窄(D=1.391),涂膜与水的静态接触角达到110°,硬度为1H,附着力为0级,分解温度为310℃.     

Preparation of antimicrobial wound dressings via thiol–ene photopolymerization reaction

Preparation of poly (urethane-acrylate) based wound dressings with the ability to boost self-healing of skin tissue through physical protection and maintaining hygiene and moist environment over wounded area is described in the present work. The dressings were prepared via a visible-light induced thiol–ene photopolymerization reaction of a mixture consisting methacrylate urethane prepolymers with hydrophilic and hydrophobic backbones, a quaternary ammonium salt containing methacrylate monomer as an antimicrobial agent, hydroxyethyl methacrylate as reactive diluent and a tetra-functional thiol molecule as a transfer agent. The prepared dressings were characterized and their performance as wound dressings were evaluated through measuring their equilibrium water absorption (EWA), water vapor transmission rate (WVTR), mechanical, and biological properties. Based on recorded data, the optimized dressing formulation had suitable tensile strength even at fully hydrated state and it could preserve the appropriate moist environment by balanced EWA and WVTR ratio. MTT assay confirmed proper cytocompatibility of those dressings containing optimized concentration of quaternary ammonium salt containing monomer (20 wt% or less). Examination of antibacterial activity against different Gram positive, Gram negative bacteria and a fungal strain revealed a complete killing ability for those dressings containing at least 20 wt% of quaternary ammonium salt containing monomer.     

高吸水性树脂的结构与吸水机理

高吸水性树脂是一种新型的功能高分子材料 ,由含强亲水性基团的单体经过适度交联使其能够吸收上百倍甚至上千倍的水 ,并且具有很强的保水性能。它的微观结构因其合成体系不同而呈现多样性。它的吸水机理可以用Flory的凝胶理论及刘廷栋的离子网络结构来解释     

Improvement of bis-GMA-based resins by urethane linkages: DTA and DSC thermal properties

Experimental bis-GMA/TEGDMA/urethane resins were investigated using synthesized urethane monomers to improve thermal properties. DTA (differential thermal analysis) results show that curing temperatures were 160 and 165°C in bis-GMA-based resins containing the synthetic 2 HEMA/N 3500 urethane monomer, 150°C in the resin containing the 2 HEMA/HT urethane monomer, and 153°C in the urethane monomer derived from 2 HEMA/N 3500. Also, DSC (differential scanning calorimetry) results show that the value of activation for polymerization during heating is lower in bis-GMA/TEGDMA containing synthesized urethane monomer (1.89, 2.44, 2.50 kcal/mol) than undiluted urethane monomer (7.50 kcal/mol) when these synthesized urethane monomers were diluted with bis-GMA/TEGDMA. With the use of urethane monomer as an additive to bis-GMA/TEGDMA it is possible to cure more rapidly with lower activation energy.     

稀释剂对环氧树脂电子束辐射固化性能的影响

对分别加入4 种稀释剂的双酚A 环氧树脂和酚醛环氧树脂的电子束辐射固化性能进行了研究。分析了稀释剂种类及含量对环氧树脂体系辐射产物的固化度、固化均匀性、固化区域大小及其动态力学性能的影响规律。结果表明: 电子束固化环氧树脂体系中加入稀释剂后, 辐射产物的固化度、玻璃化转变温度及储能模量有所下降, 但固化均匀性得到提高; 加入稀释剂的环氧树脂电子束固化区域的厚度均小于未加稀释剂树脂, 而底面直径却大于未加稀释剂树脂; 随着树脂中实际稀释剂含量的增加, 电子束固化环氧树脂固化度逐渐降低, 固化层厚度减小, 固化区域的底面直径先增加后减小。      

UV-LED喷墨油墨用单体和光引发剂性能的评估

目的 为了建立评估方法,优选出适用于UV-LED固化喷墨油墨的光引发剂和低粘度单体种类。方法 用紫外-可见光分光光度计表征TPO, ITX, DETX, 819, 784, TPO-L等常见的6种光引发剂的紫外-可见吸收光谱。采用TPO为引发剂,分别用HDDA, ACMO, DPGDA, EOEOEA, DMAA等5种常用的低粘度单体,配制UV-LED喷墨油墨用连接料和油墨,用红外光谱和可见光透过光谱表征连接料的固化速度和固化膜的颜色,并通过指压法判定表干程度。结果 DMAA, EOEOEA组成的喷墨油墨连接料成膜性不好;含有ACMO连接料的透明度较好。结论 满足食品、药品包装安全要求,可以用于UV-LED固化的光引发剂为TPO, TPO-L及819;以粘度和固化程度为标准,用于制作喷墨油墨的5种单体的适用性从高到低排序为DPGDA, HDDA, ACMO, EOEOEA, DMAA。建立的评估方法合理有效。