INVESTIGATION OF THE ATRP OF n-BUTYL METHACRYLATE USING THE Cu(I)/N,N,N',N",N"-PENTAMETHYLDIETHYLENETRIAMINE CATALYST SYSTEM

The polymerization of n-butyl methacrylate was investigated using the Atom Transfer Radical Polymerization technique with CuBr and CuCl/N,N,N',N',N'-pentamethyldiethylenetriamine catalytic systems. Various combinations of catalyst systems and initiators were utilized in order to optimize the polymerization conditions and to obtain well-defined polymers (i.e. controlled molecular weights and low polydispersities). It has been found that the optimal initiator for this system is a chlorine-based initiator, when the catalyst used is a salt in conjunction with the N,N,N',N',N'- pentamethyldiethylenetriamine ligand. Bromine-based initiators tend to result in large amounts of initial termination, leading to polymers with less than ideal chain end functionality, even if CuCl is used as the species to invoke the halogen exchange. Additionally, the effects of the polymerization temperature, species and the initiator structure were determined.

Controlled Radical Photopolymerization of n-Butyl Methacrylate in Bluk Mediated by HTEMPO

Controlled radical photopolymerization of n-butyl methacrylate（n-BMA） mediated by 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy（HTEMPO） was carried out in bulk at ambient temperature. It was found that obtained n-BMA homopolymers exhibited narrow polydispersities of around 1.4, which was characterized by GPC. Plots of number-average molecular weight vs. conversion and Ln（[Mo]/[M]） vs. time were liner respectively, indicating that was a controlled photopolymerization.

Effect of Oxygen on Surface Properties and Drug Release Behavior of Plasma Polymer of n-Butyl Methacrylate

The effects of oxygen on the chemical structure, morphology, hydrophilicity and drug release behavior of radio-frequency plasma poly n- butyl methacrylate （PPBMA） thin film were carded out for the first time. ATR-FTIR and XPS showed that oxygen had little influence on the chemical structure and composition of PPBMAs, which did not agree with the thought that the presence of oxygen gas would increase the oxidized carbon functionalities in the plasma polymer. SEM and static contact angle measurement indicated that in case of deposition with oxygen, the smoothness and hydrophilicity of PPBMA were dramatically improved. The drug release behavior showed that drug release from the PPBMA coating without oxygen was biphasic patterns, while from PPBMA coating with oxygen was Higuchi release. These results were helpful for the design and tailoring of the PPBMA polymer film and other of plasma polymers film, but could provide a new idea for the drug release controlled form.

EFFECTS OF ω-ACRYLOYL POLY (ETHYLENE OXIDE) MACROMONOMER ON EMULSIFIER-FREE EMULSI0N COPOLYMERIZATION OF METHYL METHACRYLATE AND n-BUTYL ACRYLATE

Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction termi-nating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emul-sion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containingvarious concentrations of PEO-A was studied. In all cases stable emulsion coplymerizationsof MMA and BA were obtained. The stabilizing effect was found to be dependent on themolecular weight and the feed amount of the macromonomer.

Synthesis,Characterization and Catalytic Application of H_3PW_(12)O_(40)/MCM-48 in the Esterification of Methacrylic Acid with n-butyl Alcohol

A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of n-butyl methacrylate catalyzed by H3PW12O40/MCM-48 was studied with methacrylic acid and n-butyl alcohol as reactants. H3PW12O40/MCM-48 is an excellent catalyst for synthesizing n-butyl methacrylate and Keggin structure of H3PW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n（methacrylic acid）：n（n-butyl alcohol）, catalyst dosage, cyclohexane（water-stripped reagent） and reaction time on yields of the product were investigated. The optimum conditions have been found, that is, molar ratio of acid to alcohol is 1：1.6, mass ratio of catalyst used to the reactants is 0.5% and reaction time is 2.0 h. Under these conditions, the yield of n-butyl methacrylate can reach 93.7%.

Synthesis and Characterization of Poly(isoprene-b-butyl methacrylate) Block Copolymer in the Presence of Rare Earth Catalyst

Poly(isoprene-b-butyl methacrylate) block copolymer with a high molecular weight was synthesized in the presence of rare earth coordination catalyst [RE(P 204 ) 3-Al( i Bu) 3 DBE]. The block copolymer was characterized by means of GPC,IR,DSC,NMR and elemental analysis. The block copolymer prepared has two glass transition temperatures: -75 6 ℃ and 32 2 ℃. The microstructure of the diblock copolymer possessed 96 8% cis 1,4 addition for the isoprene segment and a 70% syndiotacticity for the butyl methacrylate segment.

POLYMERIZATION OF BUTYL METHACRYLATE BY IRON PYRIDINEBISIMINE COMPLEXES

Fe(Ⅱ)pyridinebisimine complexes activated with trialkylaluminium or modified methylaluminoxane(MMAO)ascatalysts were employed for the polymerization of butyl methacrylate(BMA).Polymer yields,catalytic activities andmolecular weights as well as molecular weight distributions of BMA can be controlled over a wide range by varying thereaction parameters such as cocatalyst,Al/Fe molar ratio,monomer/catalyst molar ratio,monomer concentration and reactiontemperature used in the polymerization.The catalytic activity of Fe(Ⅱ)complex was 11.1 kg_(polym)/mol_(Fe)h and the highestyield could reach 99.1% under optimum condition.

Polymerization of Butyl Methacrylate Catalyzed by Salicylaldehyde-Imine Zirconium/Al(i-Bu)_3 System

A new kind of zirconium（Zr） complex containing ligand of salicylaldehyde-imine was successfully synthesized with ZrCl_4·2 THF and salicylaldehyde-imine as raw materials. The ligand was characterized by means of ~1HNMR, IR, and GC-MS, and Zr complex was characterized by means of ~1HNMR and IR, respectively. The Zr complex, combined with co-catalyst of Al（i-Bu）_3, was explored to be effective catalytic system for the polymerization of butyl methacrylate（BMA）, to prepare poly-n-butyl methacrylate（PBMA）, which was characterized by IR, ~13C-NMR and GPC. Compared with other double-component（MAO/Cat, AlEt_3/Cat） catalytic systems, catalytic system of Al（i-Bu）_3 and the Zr complex provided the best catalytic activity under the same conditions. The influence of polymerization parameters, such as molar ratio of Al（i-Bu）_3/Cat and BMA/Cat, polymerization temperature and polymerization time, was studied with Zr complex/Al（i-Bu）_3 system. With increasing polymerization time from 4 to 24 hour, the monomer conversion increased from 40.14% to 96.56%. Viscosity-average molecular weight（M_v） of PBMA, detected by the viscosity methodology, increased from 12.67×10~4Da to 44.97×10~4Da and lower molecular weight distribution was obtained. According to these results, the Zr complex contained ligand of salicylaldehyde-imine was a kind of readily, long lifetime and high activity catalyst for BMA polymerization.

THE EFFECTS OF N-2-HYDROXYETHYL-N-METHYL-p-TOLUIDINE ON METHYL METHACRYLATE RADICAL POLYMERI-ZATION AND ACRYLONITRILE PHOTOINDUCED POLYMERIZATION

The effects of N-2-hydroxyethyl-N-methyl-p-toluidine (HMT) on MMA polymerization using organic peroxide as an initiator and on AN photoinduced polymerization have been investigated respectively. The kinetics of polymerization and the overall activation energy of polymerization were determined. Based on kinetics study and the end group analysis of the polymer obtained by UV spectrum method, the initiation mechanism is proposed.

The Polymerization of Methyl Methacrylate in the Presence of a New Homogeneous Yttrium Catalyst

Methyl methacrylate(MMA) polymerized in the presence of a new homogeneous catalyst of Y(acac)3-(i-Bu)3Al-BuLi. The effects of MMA/Y, Al/Y, Li/Y molar ratios, polymerization temperature and time are reported. The results show that a small amount of butyl lithium could greatly enhance the activity of the catalyst and the polymerization reaction could be carried out at low temperatures (-25℃-10℃) with a high conversion. 200 kg of poly(methyl methacrylate) (PMMA) with 63% syndiotacticity could be prepared by using 1 mole of yttrium.

3D打印工艺参数对PLA/PTW共混物力学性能影响的研究

采用3D打印中的熔融沉积成型(FDM)工艺制备了聚乳酸/乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物(PLA/PTW),通过单因素实验探究了3D打印工艺参数(喷头温度、打印平台温度和打印速度)对PLA/PTW共混物力学性能的影响,并在此基础上设计了三因素三水平正交实验,优化了3D打印的工艺参数。结果表明,共混物的冲击强度和拉伸强度均随喷头温度的增加呈现先上升后下降、均随打印平台温度的增加而增加、均随打印速度的增加出现下降的趋势。各工艺参数对PLA/PTW共混物综合力学性能的影响从大到小依次为:喷头温度、打印速度、打印平台温度,且当喷头温度为210℃、打印平台温度为80℃以及打印速度为40 mm/s时,打印出的PLA/PTW共混物的综合力学性能最佳。

钛酸四丁酯催化甲基丙烯酸甲酯与正丁醇酯交换反应动力学研究

由于设备腐蚀和环境污染等问题,甲基丙烯酸丁酯生产工艺逐渐倾向于更为经济环保的酯交换生产工艺。以钛酸四丁酯为催化剂,甲基丙烯酸甲酯与正丁醇通过酯交换法合成甲基丙烯酸丁酯的反应及机理进行了初步研究。首先,根据路易斯酸催化理论,在合理假设和简化的基础上对该反应的机理进行了分析,在此基础上分别建立了基于理想溶液和非理想溶液的动力学模型。通过酯交换反应实验,主要研究了反应温度、反应物初始物质的量之比和催化剂量等因素对反应速率的影响,并根据实验数据回归得到了动力学模型参数和反应的基本热力学数据。结果显示,该酯交换反应为吸热反应,标准摩尔反应焓为14.406 kJ·mol^(-1),正、逆反应活化能分别为70.2和51.1 kJ·mol^(-1)。通过模型计算值与实验数据的比较,证明了推导得到的动力学模型具有较高的可靠性,将为钛酸四丁酯催化甲基丙烯酸甲酯与正丁醇酯交换合成甲基丙烯酸丁酯反应提供一定的理论指导。

Polypropylene/poly(butyl methacrylate) blends prepared by diffusion and subsequent polymerization of butyl methacrylate in isotactic polypropylene pellets

Polypropylene/poly（butyl methacrylate） （PP/PBMA） blends were prepared by diffusion and subseqtuent polymerization＇of butyl methacrylate （BMA） in commercial isotactic polypropylene （iPP） pellets. The diffusion kinetics, diametrical distribution of PBMA in a pellet and phase morphology of a typical PP/PBMA blend were investigated.

超韧聚乳酸/乙烯丙烯酸丁酯甲基丙烯酸缩水甘油酯共混物的制备与性能

向聚乳酸(PLA)和乙烯丙烯酸丁酯甲基丙烯酸缩水甘油酯(EBA-GMA)接枝共聚物的共混物PLA/EBA-GMA(质量比,70/30)中引入催化剂(N,N-二甲基十八胺,DMSA),通过促进PLA与EBA-GMA的原位反应增容来提高共混体系的冲击韧性,并研究了DMSA质量分数对共混体系力学性能的影响。结果显示,未添加DMSA时,PLA/EBA-GMA(70/30)共混物的冲击强度仅为10.9 kJ/m^(2)。当DMSA质量分数为0.5%时,PLA/EBA-GMA(70/30)共混物的冲击强度高达63.1 kJ/m^(2)。共混物结构与形态表征结果表明,添加少量DMSA就能有效促进EBA-GMA上环氧基团与聚乳酸端基的反应活性,提高PLA/EBA-GMA共混物的冲击韧性。

RAFT法制备羧甲基纤维素接枝丙烯酸酯共聚物

以溶解后改性的羧甲基纤维素(CMC)为大分子引发剂,S-1-十二烷基-S’-(α-α’-二甲基-α”-乙酸)三硫代碳酸酯为可逆加成断裂链转移聚合(RAFT)试剂,通过RAFT法制备了CMC接枝丙烯酸酯的新型接枝共聚物。为了进一步探索共聚物的成膜形态,设计了不同反应时间、不同甲基丙烯酸甲酯(MMA)与丙烯酸丁酯(BA)配比的反应条件,合成了CMC接枝MMA嵌段BA聚合物(Cell-g-PMMA-b-PBA)。结果表明:在反应时间为24 h,MMA与BA体积比为6∶1的条件下,Cell-g-PMMA-b-PBA的成膜性能最好,热稳定性高。

α-甲基丙烯酸叔丁酯的合成和表征及其阴离子聚合

利用酰氯醇解法合成了α甲基丙烯酸叔丁酯（ＴＢＭＡ），并通过气相色谱质谱联用仪（ＧＣ／ＭＳ）、红外吸收光谱仪（ＩＲ）、核磁共振波谱仪（ＮＭＲ）对其进行了鉴定表征。进而对ＴＢＭＡ进行阴离子聚合研究。结果表明，用１，１二苯基己基锂（ＤＰＨＬ）为引发剂，其可在１０℃下实现活性阴离子聚合。

纳米氧化钛颗粒表面处理及表征

利用偶联剂钛酸丁酯对纳米二氧化钛颗粒预处理后 ,进行甲基丙烯酸甲酯 (MMA)的聚合改性 ,研究了聚合改性物质的结构和改性后纳米二氧化钛的分散性能。钛酸丁酯与氧化钛表面羟基反应 ,使氧化钛粒子表面生成交联反应物 ,甲基丙烯酸甲酯与其反应生成 PMMA并均匀包敷于纳米二氧化钛颗粒的表面。通过聚合改性后的纳米二氧化钛颗粒在甲苯中具有良好的分散性能。

杂多酸催化合成甲基丙烯酸丁酯

报道了以杂多酸为催化剂合成甲基丙烯酸丁酯的研究结果 ,探讨了催化剂的用量、反应时间、反应温度、醇酸物质的量比等因素对反应结果的影响 ,确定了反应的最佳条件 ,讨论了催化剂的催化活性和使用寿命 .合成产品用气相色谱监测 ,并用IR和H

聚氨酯/聚(甲基丙烯酸甲酯-甲基丙烯酸丁酯)互穿聚合物网络聚合物的阻尼性能

采用本体聚合法合成出一系列阻尼性能良好的聚氨酯/聚(甲基丙烯酸甲酯-甲基丙烯酸丁酯)(PU/P(MMA-BMA))互穿聚合物网络(IPN)聚合物,通过动态力学分析方法表征了PU/P(MMA-BMA)IPN聚合物的阻尼性能。探讨了加入催化剂、高温后处理、交联剂用量及PU与P(MMA-BMA)的质量比对PU/P(MMA-BMA)IPN聚合物阻尼性能的影响。实验结果表明,经高温后处理后,以二月桂酸二丁基锡为催化剂、交联剂二乙烯基苯用量(占MMA和BMA的摩尔分数)为1.5%、PU与P(MMA-BMA)的质量比接近1或小于1时,PU/P(MMA-BMA)IPN聚合物具有良好的阻尼性能。

可乳化共聚单体AGES用于无皂乳液聚合的研究

合成了一种新型可共聚单体烯烃基甘油醚磺酸盐（ＡＧＥＳ）， 不仅含有具有反应活性的烯键， 而且带有起乳化作用的磺酸离子基团及羟基， 可用于ＭＭＡ／ＢＡ无皂乳液聚合体系． 对乳胶粒大小、乳液的流体力学行为及共聚物的动态力学性能进行了研究． 实验结果表明： 通过ＡＧＥＳ的引入， 可获得直径为０．５ μｍ 左右的分布均匀的乳胶粒， 乳液含固量高（６０％ ）， 粘度低， 是稳定的塑性非牛顿流体乳液， 共聚物为典型的无规共聚．