Photoinitiated radical polymerization of some substituted tetrahydrophthalimido and maleimidophenyl methacrylates

The photopolymerization of some substituted tetrahydrophthalimido and 4‐(maleimido)phenyl methacrylates in N,N‐dimethylformamide solutions was investigated by photo‐differential scanning calorimetry at ambient temperature. Auto‐acceleration of photopolymerization and the formation of cross‐linked products were observed as a result of temperature increases up to 60–80 °C. Substituted 4‐(maleimido)phenyl methacrylates demonstrated higher cross‐linking abilities at elevated temperatures than tetrahydrophthalimidophenyl methacrylates. Copyright © 2003 Society of Chemical Industry     

ASPAA/MMA/AN三元共聚物的合成与表征

在合成N-[4-(磺酰胺)苯基]丙烯酰胺(ASPAA)单体,并进行结构表征的基础上,以N,N-二甲基甲酰胺为溶剂,过氧化苯甲酰为引发剂,采用自由基溶液聚合合成了ASPAA／甲基丙烯酸甲酯／丙烯腈三元共聚物,用IR和^1H—NMR图谱确认了结构。共聚结果表明85℃和95℃,引发剂浓度1．0％～1．5％时,聚合初期速率较高;共聚物分子量随聚合温度和引发剂浓度增加而降低。随ASPAA含量的增加,共聚物的玻璃化温度和酸值均升高,并通过ASPAA含量来调节。     

1,4-双(3-甲基-1-苯基-5-吡唑啉酮-4-基)苯二酮的合成与表征

首次介绍通过一步反应合成１,４－双（３－甲基－１－苯基－５－吡唑啉酮－４－基）苯二酮的方法,通过元素分析、ＵＶ光谱为、ＩＲ光谱对其组成与结构进行了确认和表征,测定了产物的熔点,考察了产物在几种常见溶剂中的溶解性能。     

甲基丙烯酸丁酯-PEG梳形共聚物的合成与表征

以偶氮双异丁腈(AIBN)为引发剂,四氢呋喃为溶剂,采用甲基丙烯酸正丁酯(BMA)与聚乙二醇单甲醚甲基丙烯酸酯(POEM)共聚制备了支链上含聚乙二醇(PEG)的梳形共聚物。采用1H-NMR、DSC和表面接触角等方法研究了梳形共聚物的结构与性能。结果表明,聚合物中两结构单元的含量与单体投料比中的含量基本一致;投料比对聚合物的结构和性能有较为显著的影响;梳形聚合物的熔点、焓值及静态接触角随着共聚物中BMA含量的升高而升高。     

Thermal degradation kinetics and mechanisms of PMEPP and MEPP/MMA copolymer

In this study, 2-methacryloxyethyl phenyl phosphate (MEPP), a phosphorus-containing flame retardant, was synthesised via the esterification of phenyl dichlorophosphate (PDCP) with 2-hydroxyethyl ethylene methacrylate (HEMA), followed by hydrolysis. A two-stage bulk polymerisation process prepared MEPP/methyl methacrylate (MEPP/MMA) copolymers containing various amounts of MEPP. The condensed-phase and volatized products produced at various temperatures during the thermal degradation of MEPP/MMA copolymer were monitored by Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis with Fourier transform infrared spectroscopy (TGA/FT-IR). Finally, we propose the possible mechanisms for the thermal degradation of MEPP/MMA copolymer according to the analytical results of the condensed-phase and volatilized products.     

Role of a small amount of comonomer on the physical aging of poly(methyl methacrylate) copolymer investigated by dynamic viscoelasticity

The physical aging of a poly(methyl methacrylate) (PMMA) copolymer having a small amount of ethyl methacrylate was investigated below its glass transition temperature (T_g) using dynamic viscoelastic measurements. The results were compared with those from homo-PMMAs to investigate how the comonomer in the copolymer affects the physical aging of the glass. Annealing temperatures were classified into two categories by the glass transition temperature of a poly(ethyl methacrylate) (T_gPEMA; ca. 65°C). The relaxation rate of the copolymer was faster than those of the homo-PMMAs when the samples were aged below T_gPEMA, but the rates were equal when aged at above T_gPEMA. The experimental results are discussed in terms of the segmental motion.     

HPLC法测定N-羟基-N-(2-((1-(4-氯苯基)-1H-吡唑-3-基)氧)甲基)苯基氨基甲酸甲酯

采用Aglient Extend-C185μm 250 mm×4.6 mm色谱柱,流动相为甲醇-0.4%磷酸溶液(v∶v=75∶25),流速为1 m L/min,275 nm为检测波长,建立了测定N-羟基-N-(2-((1-(4-氯苯基)-1H-吡唑-3-基)氧)甲基)苯基氨基甲酸甲酯含量的高效液相色谱分析方法。在进样量为0.53~3.52μg的范围内线性关系良好(y=125679.4x+15010.4,r=0.9999),RSD 0.24%,回收率99.2%~100.4%,分析周期为15 min。方法快速、简便、准确,可用于N-羟基-N-(2-((1-(4-氯苯基)-1H-吡唑-3-基)氧)甲基)苯基氨基甲酸甲酯反应液及产品的质量控制。     

β-肾上腺素受体阻滞剂艾司洛尔中间体的初步合成

对羟基苯丙酸甲酯与环氧氯丙烷,以碳酸钾为催化剂,以PEG400为助催化剂,回流反应24小时,初步制得标题化合物,收率68%。     

Copolymers of 2-hydroxyethyl methacrylate and methyl methacrylate: an electron beam resist study

The electron beam development characteristics of copolymers of HEMA and MMA are reported. A copolymer with 4% of HEMA was found to have comparable sensitivity and enhanced contrast compared with conventional PMMA and this material would appear to be useful in lithographic applications.     

Isotactic polypropylene/polymethylmethacrylate blends: Effects of addition of propylene-graft-methylmethacrylate copolymer

A novel graft copolymer of unsaturated propylene with methyl methacrylate (uPP-g-PMMA) was added to binary blends of isotactic polypropylene (iPP) and atactic poly(methyl methacrylate) (aPMMA) with a view to using such a copolymer as a compatibilizer for iPP/aPMMA materials. Optical microscopy (OM), scanning electron microscopy, wide angle X-ray scattering (WAXS), and small angle X-ray scattering (SAXS) techniques showed that, contrary to expectation, the uPP-g-PMMA addition does not provide iPP/aPMMA compatibilized materials, irrespective of composition. As a matter of fact the degree of dispersion of the minor component achieved following the addition of uPP-g-PMMA copolymer remained quite comparable to that exhibited by binary blends of iPP and aPMMA with no relevant evidence of adhesion or interconnection between the phases. On the other hand the crystalline texture was deeply modified by the copolymer presence. With increasing uPP-g-PMMA content (w/w) the iPP spherulites were found to become more open and coarse and the dimensions and number per unit area of the amorphous interspherulitic contact regions were found to increase. According to such OM results the copolymer uncrystallizable sequences were assumed to be mainly located in interfibrillar and interspherulitic amorphous contact regions. SAXS analysis demonstrated that the phase structure developed in the iPP/aPMMA/uPP-g-PMMA blends is characterized by values of the long period increasing linearly with increasing copolymer content (w/w). Assuming a two phase model for the iPP spherulite fibrillae, constituted of alternating parallel crystalline lamellae and amorphous layers, the lamellar structure of the iPP phase in the ternary blends is characterized by crystalline lamellar thickness (L_c) and an interlamellar amorphous layer (L_a) higher than that shown by plain iPP and L_c and L_a values both increased with increasing uPP-g-PMMA content (w/w). Such SAXS results have been accounted for by assuming that a cocrystallization phenomenon between propylenic sequences of the uPP-g-PMMA copolymer and iPP occurs. The development of the iPP lamellar structure in the iPP/aPMMA/uPP-g-PMMA blends was thus modeled hypothesizing that during such a cocrystallization process copolymer PMMA chains with comparatively lower molecular mass remain entrapped into the iPP interlamellar amorphous layer forming their own domains. Moreover, evidence of strong correlations between the crystallization process of the uPP-g-PMMA copolymer and the iPP crystallization process was shown also by differential scanning calorimetry and WAXS experiments. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2377–2393, 1997     

不同组成ABS对ABS／PMMA合金性能的影响

选用两种不同牌号的ABS树脂与PMMA共混，对其组成与性能的关系进行了详细的研究。试验结果表明，不同组成的ABS对ABS/PMMA混合物的光学性能、力学性能以及流变行为的影响都有显著的不同．     

The inverse emulsion polymerization of acrylamide using poly(methyl methacrylate)‐graft‐polyoxyethylene as the stabilizer

Inverse emulsion polymerization of an aqueous solution of acrylamide (AM) in toluene is carried out using poly(methyl methacrylate)‐graft‐polyoxyethylene (PMMA‐g‐PEO) as an emulsifier. The kinetics of polymerization, morphology of the particle, and particle size of the inverse emulsion have been investigated. The rates of polymerization are found to be proportional to the initiator concentration, the monomer concentration, and the emulsifier concentration. The morphology of particles shows a spherical structure. The mechanism of inverse emulsion polymerization using amphipathic graft copolymer as the emulsifier is proposed. The resulting molecular weights of polyacrylamide are extremely high, and relate to the amphipathic graft copolymer structure. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 528–534, 2001     

Preparation of PMMA–PS–PMMA via combination of anionic and photoinduced charge‐transfer polymerization

PMMA–PS–PMMA triblock copolymers were prepared by the combination of an anionic mechanism with charge‐transfer polymerization. Polystyrene with aromatic tertiary amino groups at both ends (PS_ba) was synthesized first by the reaction of a living polystyrene macrodianion with excess p‐(dimethylamino)benzaldehyde; then, the PS_ba was constituted into a binary system with benzophenone (BP) to initiate the polymerization of methyl methacrylate (MMA) under UV irradiation. The intermediate and resulting block copolymers were characterized by GPC, IR, and ¹H‐NMR. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2072–2076, 1999     

Vapor sorption in thin supported polymer films studied by white light interferometry

In the present study, we apply a white light interferometric methodology to study sorption of moisture and methanol vapor in thin films of poly(2-hydroxyethyl methacrylate) [PHEMA] and poly(methyl methacrylate) [PMMA], supported on oxidized silicon wafers. The measured equilibrium thickness expansion of each film, exposed to different activities of the vapor penetrant, is used to determine the sorption isotherm of the system. Results for relatively thick films (100 nm < L_o < 600 nm) are compared with corresponding literature data for bulk, free-standing films, obtained by direct gravimetric methods. Furthermore, PMMA films of thicknesses lower than 100 nm were employed in order to study the effect of the dry film's thickness, and of substrate, on fractional swelling.