交联PMMA微球表面PS刷子的合成与表征

将含有双键的甲基丙烯酸-2-氨基乙酯化学锚接在交联聚甲基丙烯酸甲酯微球表面,然后用过氧化苯甲酰引发苯乙烯发生氮氧调控自由基原位接枝聚合反应,将聚苯乙烯接枝在交联聚甲基丙烯酸甲酯微球表面,制备了PS刷子层.用凝胶渗透色谱和红外光谱对所合成交联聚苯乙烯接枝聚甲基丙烯酸乙酯共聚物进行了表征,实验结果显示：在2,2,6,6-四甲基哌啶-1-氧自由基存在下,苯乙烯的聚合反应为＂活性＂自由基聚合,所得到的聚苯乙烯分子量分布在1.13～1.28范围,分子量随聚合时间的延长而增大（7 000～68 000 g/mol）.接枝聚合物红外光谱显示聚苯乙烯被接枝到了交联聚甲基丙烯酸甲酯微球表面.AFM 表征显示交联聚甲基丙烯酸甲酯微球尺寸在0.3～1.6 μm 范围.     

交联PS微球表面PEMA刷子的合成与表征

将含有双键的N,N-二甲氨基甲基丙烯酸乙酯化学锚接在交联聚苯乙烯（PS）微球表面,再用过氧化苯甲酰引发甲基丙烯酸乙酯（EMA）氮氧调控自由基原位接枝聚合反应．将聚甲基丙烯酸乙酯（PEMA）接枝在交联PS微球表面,制备了PEMA刷子层;研究了聚合反应机理．并对所合成交联PS接枝PEMA共聚物进行了表征。结果表明,在2,2,6．6-四甲基哌啶-1-氧自由基存在下,EMA的聚合反应为“活性”自由基聚合．所得到的PEMA摩尔质量分布在1．18—1．3范围,摩尔质量随聚合时间的延长而增大（9000～57000g／mol）;红外光谱显示PEMA被接枝到了交联PS微球表面,交联PS微球粒径在0．5—1．2μm之间。     

可控/活性聚合在无机粒子表面接枝研究进展

介绍了一些主要的可控／活性自由基聚合法,包括氮氧调解自由基聚合法（NMRP）、原子转移自由基聚合法（ATRP）、可逆加成断裂链转移聚合法（RAFT）在粒子表面接枝聚合形成无机纳米粒子／聚合物的壳核结构,达到了对粒子改性的目的。并提出了一些目前研究中存在的问题,对可控／活性聚合应用的发展进行了展望。     

LDPE悬浮聚合接枝PS及其表征

研究了ＬＤＰＥ悬浮接枝ＰＳ合成ＬＤＰＥ－ｇ－ＰＳ接枝共聚物的工艺，此接枝共聚物可作为某些聚合物共混的相容剂。讨论了苯乙烯溶胀ＬＤＰＥ时间、引发剂浓度和ＬＤＰＥ与苯乙烯投料比对接枝率的影响，发现溶胀时间为４ｈ、反应时间为８ｈ、引发剂浓度为１％时、ＬＤＰＥ与苯乙烯投料比为１∶１时，其接枝共聚物接枝率最大可达３８．５％。并对ＬＤＰＥ－ｇ－ＰＳ接枝共聚物进行了ＤＳＣ、ＩＲ及接枝率测定的表征。     

纳米Al_2O_3表面接枝聚合改性的研究

为改善纳米Al2O3粒子在聚合物中的分散状况,本工作先在粒子表面引入双键,然后通过溶液自由基引发接枝单体丙烯酰胺和苯乙烯在Al2O3粒子表面的聚合,使接枝物与纳米粒子之间形成化学键合。系统研究了投料方式、引发剂浓度、单体浓度、反应时间等对接枝效果的影响,为调控纳米粒子表面的化学性质提供依据。     

表面引发原子转移自由基聚合制备甲基丙烯酸甲酯接枝废胶粉及其表征

采用原子转移自由基聚合法研究了废胶粉(GTR)的表面化学接枝改性,包括2-溴异丁酰溴(BIBB)与GTR表面羟基的反应,以及形成的大分子引发剂引发甲基丙烯酸甲酯(MMA)的接枝聚合反应;用红外光谱和X射线光电子能谱仪、热重分析和扫描电子显微镜对接枝改性反应前后的GTR表面进行了表征.结果表明,GTR表面含有一定量羟基,...     

纳米铁粒子表面接枝聚合甲基丙烯酸甲酯

采用直流电弧等离子体法制备纳米铁粉,利用甲基丙烯酸(MAA)和盐酸处理纳米铁粉,通过乳液聚合方法,在纳米铁粉存在下MMA原位聚合,形成纳米铁/聚甲基丙烯酸甲酯复合粒子。分析结果表明,MMA在纳米铁粒子表面接枝聚合,纳米铁粉表面的双键参与了聚合反应,所形成的复合粒子具有核壳结构,这种复合粒子具有较高的稳定性。     

二醋酸纤维素接枝聚甲基丙烯酸甲酯的合成与表征

以二醋酸纤维素（CDA）为接枝骨架,利用原子转移自由基聚合(ATRP)技术接枝聚甲基丙烯酸甲酯(PMMA),合成接枝共聚物(CDA-g-PMMA),采用FT-IR、1H-NMR、DSC、XRD和GPC等方法表征了CDA-g-PMMA的结构与物化性能,结果显示,支链PMMA的引入,降低了材料的熔融温度和结晶度,另外还增加了材料的韧性,ATRP方法有效的控制了共聚物相对分子质量分布系数。     

表面接枝PDEGMA纤维素纳米晶的制备及其温敏性

通过电子转移再生催化剂原子转移自由基聚合法(ARGET ATRP)制备了表面接枝聚二(乙二醇)甲基醚甲基丙烯酸甲酯(PDEGMA)的温敏性纤维素纳米晶(CNC-PDEGMA)。红外光谱和热重分析曲线表明纤维素纳米晶表面上成功地接枝了PDEGMA聚合物刷。CNC-PDEGMA室温条件下能在水溶液中稳定分散,温度升高至50℃时絮聚析出,在水溶液中表现出温敏性。CNC-PDEGMA固态薄膜在室温下亲水,高温下疏水且接触角稳定在120o以上,同样表现出明显的温敏性。     

原子转移自由基聚合法合成PS-g-PMMA

以氯乙酰化聚苯乙烯微球（PS-acyl-Cl）为大分子引发剂,甲基丙烯酸甲酯（MMA）为单体,CuCl/CuCl₂及N,N,N′,N′-四甲基乙二胺（TMEDA）为催化体系的原子转移自由基聚合反应,成功在PS-acyl-Cl表面接枝上PMMA分子链而获得聚苯乙烯 接枝 聚甲基丙烯酸甲酯（PS-g-PMMA）。考察了催化剂、反应温度、溶剂用量等条件对接枝反应的影响,优化的反应条件下,使用氯乙酰基担载量3.44 mmol.g^-1的PS-acyl-Cl,15 h可获得增重率687% 的PS-g-PMMA,且反应表现出一级动力学特征（k=513×10^-5 s^-1）。通过改变反应条件,可得到不同PMMA接枝链长的PS-g-PMMA。反应得到的PS-g-PMMA经水解后有望作为高担载量弱酸型离子交换树脂或进一步功能化后作为酶的柔性固定化载体。     

Grafting of poly(methyl methacrylate) or polyacrylonitrile onto polystyrene using ATRP technique

One of the most useful methods for synthesizing the graft and well‐defined copolymers is the atom transfer radical polymerization (ATRP) method. The polymerization was initiated by polystyrene (PS) carrying chloroacetyl groups as macroinitiator, in the presence of copper chloride (CuCl) and bipyridine (bpy). The macroinitiator (chloroacetylated PS) was prepared by successive chloroacetylation of PS under mild conditions and these reaction conditions overcome the problem of gelation and crosslinking in polymers. Successful graft copolymerizations were performed with methyl methacrylate (MMA) in toluene at 80°C and with acrylonitrile (AN) in tetrahydrofuran/ethylenecarbonate (62.5/37.5 v/v %) mixed solvent at 55°C. The characterization of the copolymers was investigated by ¹H‐NMR and FT‐IR spectroscopices. Gel permeation chromatography measurement indicated an increase of the molecular weight of the graft copolymers, as compared to that of the macroinitiator. This measurement also indicated the monomodal molecular weight distribution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2619–2627, 2006     

Grafting of partially hydrolysed poly(methyl methacrylate) onto mesylated cellulose acetate

A new synthetic route to cellulose graft polymers by nucleophilic displacement of mesylate groups from mesyl cellulose acetate (MCA) by the polystyrylcarboxylate anion has been recently reported by us. This approach to cellulosic graft polymers overcomes the drawbacks of the radical polymerization methods and allows for precise control of parameters such as the molecular weight and molecular weight distribution of the grafted side chains, higher degree of substitution on the cellulose backbone, the number and nature of grafted side chains and overall better control and reproducibility of the grafting process. In this report, partially hydrolysed poly(methyl methacrylate) was successfully grafted on to mesylated cellulose acetate in excellent yields by nucleophilic displacement of mesylate groups in less than 60 min at 75°C.     

SBS接枝MMA合成的共聚物对PS/PVC共聚物增容作用的研究

结合共聚原理,成功地确定了此接枝共聚物作为PS/PVC共混体系的增容作用。并分析了此接枝共聚物的力学性能。应用接枝或嵌段共聚物作为第3组分加入到二元不相容的高聚物共混体系中被认为是控制相态结构、改善力学性能简单而有效的方法。由此,合成非反应性接枝共聚物作为二元不相容的高聚物共混物的第3组分是研究的主要课题。     

Synthesis and properties of poly(methyl methacrylate)/montmorillonite (PMMA/MMT) nanocomposites

PMMA/MMT nanocomposites were successfully synthesized via in situ intercalative polymerization, and characterized by means of wide‐angle X‐ray diffractometry, transmission electron microscopy, thermal gravimetric analysis, dynamic mechanical analysis and Fourier‐transform infrared analysis. The nanocomposites possess partially exfoliated and partially intercalated structure, in which the silicate layers are exfoliated into nanometre secondary particles with thickness of less than 20 nm and uniformly dispersed in the polymer matrix. In comparison with pure PMMA, the thermal stability, glass transition temperature, and mechanical properties of the polymer are notably improved by the presence of the nanometric silicate layers. It was found that part of the PMMA chains in the nanocomposites are well immobilized inside and/or onto the layered silicates and, therefore, the unique properties of the nanocomposites result from the strong interactions between the nanometric silicate layers and the polymer chains. Copyright © 2003 Society of Chemical Industry     

Morphology and thermodynamic analysis of composite polymer particles prepared by soap‐free emulsion polymerization in the presence of poly(methyl methacrylate) and polystyrene as biseeds

Biseeds emulsion polymerization was investigated with poly(methyl methacrylate) (PMMA) and polystyrene (PSt) as biseeds and styrene (St) as second‐stage monomer, as well as with thermodynamic analysis; namely, the principle of minimum interfacial free‐energy change was utilized to explain the competitiveness of different seeds for second‐stage monomer and the final equilibrium morphology of composite polymer particles. The experimental results indicated the polymeric particles prepared had bimodal size distribution and the PMMA seed particles showed a higher chance of obtaining St than that of the PSt seed particles, which was in agreement with the computational outcome by the principle of minimum interfacial free‐energy change. Owing to the kinetic factors, the equilibrium morphology could not be reached in the experiments. However, the results demonstrated that double or multiple seeds emulsion polymerization could be used as a model experiment to study the morphology of polymer particle and the morphological prediction. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2675–2680, 2004     

Soap-free seeded emulsion copolymerization of MMA onto PU-A and their properties

The polyurethane acrylate (PU-A) containing double bond and COOH group was synthesized by stepwise reaction of 2,4-toluene diisocyanate (TDI), polyetherdiol (PPG), dimethylolpropionic acid (DMPA), and 2-hydroxpropyl acrylate (HPA), and the PU-A was neutralized with triethylamine (TEA) and self-emulsified in water to form the PU-A emulsion seed. Adding methyl methacrylate (MMA) into PU-A seed, the seeded emulsion copolymerization of MMA onto PU-A seed had been carried out at 80°C under the soap-free condition to obtain anionic latex of P(UA-MMA). The kinetic behavior of the seeded emulsion copolymerization, the MMA grafting ratio, and the crosslinking copolymer were investigated. IR spectra showed that it did form the P(UA-MMA) copolymer. The measurements revealed that the structure of the P(UA-MMA) copolymer, its latex properties and the cast film were significantly influenced by the amounts of HPA, DMPA, and MMA. The experimental results indicated that with DMPA increased, the particle size of P(UA-MMA) latex decreased, but the tensile strength of its cast film increased. Adding a small amount of HPA, it could improve the tensile strength of the cast film. With MMA content increased, the distribution of the particle size of P(UA-MMA) latex became narrow, whereas under certain amount of MMA, the tensile strength of the cast film was enhanced. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 941–947, 2001     

四官能度过氧化物JWEB50引发的PS-b-PMMA合成与表征

引言嵌段共聚物是具有两种或两种以上不同链段的聚合物,不同链段间存在的化学键限制了聚合物的相分离程度,易形成微相分离结构[1],而嵌段共聚物能作为聚合物共混体系的相容剂,只需加入少量     

Polymerization of methyl methacrylate with mechano-chemically synthesized macroinitiators

The polymerization of methyl methacrylate initiated by acrylonitrile- based homopolymers and copolymers synthesized mechanochemically by vibratory milling has been studied. The factors influencing the conversion and poly(methyl mehtacrylate) molecular weight are discussed. Both characteristics depend on polymerization parameters (reaction time, temperature and initiator concentration) as well as on macroinitiator synthesis conditions (duration of the vibratory milling process, comonomer ratio). The polymerization product consists of poly(methyl methacrylate) and small amounts of poly(acrylonitrile-g-methyl methacrylate)copolymer.