种子乳液法制备水性环氧树脂涂料的研究

本文通过半连续种子乳液聚合方法用甲基丙烯酸、苯乙烯、丙烯酸丁酯与环氧树脂反应制备得到了水性环氧树脂涂料。讨论了乳化过程中乳化温度、复合乳化剂用量、滴加速度对乳液粘度及分水率的关系,确定了最佳反应条件为温度80℃、复合乳化剂用量3.6g、滴加速度0.5ml/min。利用傅里叶红外光谱对产物结构进行表征,说明发生了接枝聚合反应。TEM和粒径分析结果表明制备的涂料为核壳结构,粒径大小在50-100nm。     

纳米Si02／MMA无皂乳液聚合研究及其应用

以纳米SiO2为核。以MMA为壳层单体，进行了无皂乳液聚合。研究了单体加入方式、引发剂用量、聚合反应温度等对无皂乳液聚合的影响。核壳产物对PVC材料的力学性能有明显的提高。     

ASA核—壳乳液聚合研究：Ⅲ 聚合动力学和接枝率

以交联的聚丙烯酸丁酯为核(橡胶相),以苯乙烯/丙烯腈共聚物为壳(塑料相),考察了核一壳乳液聚合动力学;并研究了一些聚合参数对接枝率的影响,利用傅里叶变换红外光谱仪和Perkin-Elmer240C元素分析仪对接枝物进行了定性定量表征。     

聚丙烯酸酯无皂核壳乳液聚合反应的研究

采用无乳液聚合技术，合成了PBA／PMMA核壳结构的复合乳液，研究齐聚物用量及配比、温度，DDM对齐聚物聚合反应速率的影响，以及引发剂浓度，齐聚物浓度等因素对核壳乳液聚合速率的影响。     

乳液聚合中单体醋酸乙烯酯与保护胶体聚乙烯醇的接枝反应研究

研究了以聚乙烯醇为保护胶体的醋酸乙烯乳液聚合中,聚乙烯醇与单体的接枝反应。探讨了引发剂用量、聚合反应温度、保护胶体聚合度等因素对接枝反应的影响。     

纳米SiO_2/MMA无皂乳液聚合研究及其应用

以纳米 Si O2 为核 ,以 MMA为壳层单体 ,进行了无皂乳液聚合。研究了单体加入方式、引发剂用量、聚合反应温度等对无皂乳液聚合的影响。核壳产物对 PVC材料的力学性能有明显的提高。     

含功能基的核—壳型聚丙烯酸酯乳液的合成与性能

本文以种子乳液聚合法制备了PBA/MMA-MAA核-壳型聚合物,考察了壳层单体MMA和MAA的含量不同时对聚合反应及聚合物其它性能的影响,并用TEM观察了粒子的形态。     

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。     

新型核壳型纳米球形聚电解质刷的制备

采用光乳液聚合法成功合成了一种纳米球形聚电解质刷,该纳米球形聚电解质刷由核、壳两部分组成:核为直径320nm的聚丁二烯胶乳微球,壳为在其表面接枝的长度和接枝密度可控的线性聚丙烯酸链.分别比较了不同反应温度和引发时间对聚电解质刷接枝密度的影响.结果表明:纳米球形聚电解质刷粒径(D)和离子强度(C<,I>)之间在实验范围内...     

丙烯酸酯类无皂复合乳液聚合机理的研究

从热力学、接枝工艺方面阐述了丙烯酸酯类复合乳液聚合机理,同时用实验验证了机理的合理性,提出了“涂层－接枝”核／壳结构机理。     

线型低密度聚乙烯固相接枝丙烯酸丁酯的研究

利用固相接枝共聚的方法,制备了线型低密度聚乙烯接枝丙烯酸丁酯(LLDPE-g-BA)共聚物。讨论了反应温度、反应时间、引发剂用量、单体浓度对接枝率的影响,结果表明:随着反应温度的升高,反应时间的延长,引发剂用量以及单体/聚合物比例的增加,接枝率提高,最高接枝率达到10.12%。并用红外光谱表征产物的结构。LLDPE-g-BA可明显改善PET/LLDPE复合材料的界面相容性及力学性能。     

Preparation and characterization of henequen cellulose grafted with methyl methacrylate and its application in composites

The grafting polymerization of methyl methacrylate (MMA) and cellulose from henequen (Agave fourcroydes) is investigated as a function of the initiator concentration (cerium-and-ammonium nitrate) and the monomer/cellulose ratio. The formation of cellulose-g-PMMA is confirmed by IR spectroscopy, DSC, and TGA. Both the initiator concentration and the MMA/cellulose ratio have a strong influence over the grafting parameters and over the molecular weight of the grafted PMMA. A higher initiator concentration and a lower monomer/cellulose ratio result in a lower molecular weight of the grafted polymer. Increasing the amount and the molecular weight of the grafted PMMA increases the compatibility of the fibers with SAN and PVC, as demonstrated by a mechanical test and scanning electron microscopy. SAN and PVC composites made with grafted cellulose exhibit higher flexural and tensile moduli, respectively, than those produced with the ungrafted fibers. Both moduli increase as the amount of reinforcement increases. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 339–346, 1997     

废PSF接枝改性物的粘接性能

用溶液接枝的方法研究了回收的废聚苯乙烯泡沫塑料的接枝工艺,其包括:引发剂量、反应温度、单体浓度、单体种类、多单体共接枝的影响。作者还研究了增粘剂与PS接枝物的相容性,从而配制了粘接性能良好的粘合剂,这种粘合剂还有优良的耐水性。     

The graft photopolymerization of acrylates and methacrylates on wool in dimethyl sulfoxide

Irradiation of wool by short-wavelength ultraviolet light in the presence of acrylate or methacrylate esters in dimethyl sulfoxide causes intermediate grafts (2%–10%) of polymer on the surface of the wool. The amount of grafting and homopolymerization and the evenness and regularity of photografted polymer are dependent upon the monomer used. With methyl acrylate, the reaction time, monomer concentration, and introduction of water as cosolvent affect the degree of fiber grafting and the amount and molecular weight of accompanying homopolymer. Polymers grafted onto wool by this technique change the tensile properties and the water desorption characteristics of the wool.     

Mechanism and grafting reactions in seeded emulsion polymerization with emulsified monomer feeding

The seeded emulsion polymerization of styrene with emulsified monomer feeding was performed by polyethyl acrylate (PEA) latex as seed emulsion. It was shown that the grafting reactions occurred between two components on the composite latex particles. The loci of seeded polymerization were studied by the kinetics of grafting reaction. The highest grafting efficiency in the initial period of seeded emulsion polymerization supported the fact that the surfaces of PEA particles are the sites of polymerization of styrene. The grafting efficiency decreased with increasing monomer‐to‐polymer ratio and initiator concentration. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1495–1499, 1999     

EPDM/PP的接枝改性及在超韧尼龙中的应用研究

研究了引发剂、接枝单体用量及阻交联剂品种对含有聚丙烯的三元乙丙橡胶熔融接枝马来酸酐接枝率的影响。结果表明:引发剂的含量是获取高接枝率的关键,当过氧化二异丙苯的加入量为0.08%,马来酸酐的用量为1.2%时,体系的接枝率在1%左右。并讨论了接枝物在超韧尼龙合金中的应用。     

Radiation induced grafting of mixed monomers onto polyester and polypropylene fibers

Grafting of the mixture of acrylamide and acrylic acid onto polyester and polypropylene fibers and mixture of acrylic acid and methacrylic acid onto polypropylene by the radiation method are reported. It is observed that when pure acrylamide was used for grafting, the grafting extent was small, whereas when the mixture was used, the amount of acrylamide content in the copolymer was found to be more than the feed ratios. The results are explained on the basis of chain transfer mechanism. With methacrylic acid and acrylic acid mixtures, the rate of grafting decreased with the increase in the concentration of acrylic acid in the feed ratio, and this has been explained on the basis of the formation of either a 3-dimensional network structure or a highly branched structure involving backbone polymer molecules with acrylic acid, which prevents the diffusion of the monomer from the solution phase to the swollen phase.     

Graft copolymerization onto starch. IV. Grafting of methyl methacrylate to granular native potato starch by manganic pyrophosphate initiation

A study has been made of graft copolymerization of methyl methacrylate onto native potato starch in aqueous slurry at 30°C. As Mn³⁺ concentration was increased from 0.15 X 10^-3M to 1.0 X 10^-3M, conversion of monomer to polymer and add-on of polymer to starch increased and frequency of grafts (anhydroglucose units per grafted chain) decreased sharply. The average molecular weights of the PMMA grafts also decreased in this range. At Mn³⁺ concentrations from 1.0 X 10^-3M to 3.0 X 10^-3M, only minor changes in grafting parameters were observed. When the amount of starch charged per batch was increased threefold, the add-on decreased sharply, the molecular weight increased slightly, and the conversion of MMA monomer to polymer remained almost constant. The increase in frequency of grafts (AGU/chain) was almost directly proportional to the increase in the amount of starch charged. In all cases the average molecular weights of grafts were of the order of 10⁶ and the grafting efficiencies high, normally greater than 85%. These results were compared with those previously obtained for grafting of acrylonitrile onto starch. They were interpreted in terms of initial (Mn³⁺)/(AGU) ratio, total number of radicals initiating grafting, and compatibility of methyl methacrylate monomer with poly(methyl methacrylate) chains.     

Graft polymerization of vinyl acetate onto silica

The free‐radical graft polymerization of vinyl acetate onto nonporous silica particles was studied experimentally. The grafting procedure consisted of surface activation with vinyltrimethoxysilane, followed by free‐radical graft polymerization of vinyl acetate in ethyl acetate with 2,2′‐azobis(2,4‐dimethylpentanenitrile) initiator. Initial monomer concentration was varied from 10 to 40% by volume and the reaction was spanned from 50 to 70°C. The resulting grafted polymer, which was stable over a wide range of pH levels, consisted of polymer chains that are terminally and covalently bonded to the silica substrate. The experimental polymerization rate order, with respect to monomer concentration, ranged from 1.61 to 2.00, consistent with the kinetic order for the high polymerization regime. The corresponding rate order for polymer grafting varied from 1.24 to 1.43. The polymer graft yield increased with both initial monomer concentration and reaction temperature, and the polymer‐grafted surface became more hydrophobic with increasing polymer graft yield. The present study suggests that a denser grafted polymer phase of shorter chains was created upon increasing temperature. On the other hand, both polymer chain length and polymer graft density increased with initial monomer concentration. Atomic force microscopy–determined topology of the polymer‐grafted surface revealed a distribution of surface clusters and surface elevations consistent with the expected broad molecular‐weight distribution for free‐radical polymerization. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 300–310, 2003     

ST-g-NMA-AM的制备及其吸附性能

以红薯淀粉(ST)为原料,丙烯酰胺(AM)为单体,N-羟甲基丙烯酰胺(NMA)为单体和交联剂,采用反向乳液聚合法制备了NMA-AM接枝ST(ST-g-NMA-AM)。考察了NMA用量、引发剂过硫酸铵用量及反应温度对接枝率的影响,利用傅里叶变换红外光谱对其结构进行表征。以亚甲基蓝为吸附质,考察了ST-g-NMA-AM对亚甲基蓝的吸附性能。结果表明:当NMA用量为0.75 g,引发剂用量为0.0500 g,反应温度为55℃时,单体转化率和接枝率最高,分别为90.41%,45.38%;当亚甲基蓝质量浓度为20 mg/L,吸附剂ST-g-NMA-AM质量浓度为1 g/L时,吸附量随着NMA用量的增加而先增大后减小,当引发剂用量为0.0500 g,NMA用量为0.75 g时,吸附量最大,为16.140 mg/g。