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1.
L. F. Kosyanchuk N. V. Kozak O. I. Antonenko G. Ya. Menzheres Yu. S. Lipatov 《Theoretical and Experimental Chemistry》2006,42(6):357-363
For semi-interpenetrating polymer networks (semi-IPNs) based on an incompatible polyurethane network/linear polymethylmethacrylate
pair formed in situ in the presence of 3d metal chelates, we have studied the effect of the system composition on the kinetics
of formation of the components and the nature of complex formation between the metal compound and the polymer matrix. The
ratio of the system components has been shown to have an effect on the selection of the macroligand in formation of complexes
of the metal chelate with the polar groups of the semi-IPN, where the general character of the kinetic behavior for the formation
of the network and the linear polymer is preserved.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 6, pp. 351–356, November–December, 2006. 相似文献
2.
The effect of low-energy ion bombardment on CD4/O2 and CF3X (X=F, Cl, Br) plasma etching has been assessed by applying controlled rf bias voltages on polystyrene (PS) and polymethylmethacrylate (PMMA) samples. In both cases ion bombardment has been found to have a chemical effect. In the case of CF4/O2 discharges, ion bombardment has been found to change the relative etching efficiency of different mixtures. In the case of CF3X plasmas, ion bombardment has been found to alter PMMA and PS etch rates in a different way. In particular, the ratios between CF4 and CF3X (X=Cl, Br) etch rates of PS have been found to decrease with increasing bias voltage. This effect has been tentatively attributed to an ion bombardment-induced enhancement of the reaction between the aromatic ring and halogen molecules formed in CF3Cl and CF3Br discharges. 相似文献
3.
The objective of the present study was to determine the best molecular balance between the two hydrogenated polybutadiene (HPB) and polymethylmethacrylate (PMMA) blocks that promotes an HPB‐b‐PMMA diblock copolymer with efficient compatibilization activity in a low‐density polyethylene (LDPE)/PMMA immiscible blend. The model blend selected, LDPE/PMMA, is “more immiscible” than the LDPE/polystyrene pair largely reported in open literature. The blends having a composition of 80LDPE/20PMMA exhibit a droplet‐in‐matrix phase morphology whereas in 20LDPE/80PMMA a co‐continuous phase morphology was developed. In the droplet‐in‐matrix phase morphology, the emulsifying efficiency of the copolymer was evaluated based on the maximum reduction of the PMMA droplet size it is able to promote. Whereas, in the co‐continuous phase morphology, the copolymer was evaluated based on its ability to stabilize the maximum phase co‐continuity. The sequences of the best emulsifying copolymer revealed are not symmetrical. An HPB‐b‐PMMA where the ratio of molar mass of the blocks, HPB/ PMMA, is within 1.8–1.95 exhibits a much better interfacial activity in LDPE/PMMA blends than a copolymer of much lower ratio (longer PMMA block). This is ascribed to the much higher interactions (cohesive energy density) encountered in PMMA (PMMA of the copolymer and PMMA phase of the blend) compared with the LDPE side (HPB of the copolymer and LDPE phase of the blend). © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 837–848, 2005 相似文献
4.
Highly monodisperse polymethylmethacrylate (PMMA) microparticles crosslinked with carboxylic group-containing urethane acrylates
(CUA) were produced by simple dispersion polymerization in methanol solution. In contrast to conventional crosslinkers, the
CUA employed as a crosslinker was excellent for maintaining the monodispersity of PMMA microparticles even at moderate crosslinker
concentrations (to about 5 wt%). It was believed that the CUA helped form the monomer-swellable surface of primary particles,
because of the structurally long tetramethylene oxide groups in the molecule. Carboxylic groups in the molecular backbone
resulted in larger primary particles by increasing the solubility of the monomer mixture in the medium. Owing to these larger
primary particles, the crosslinked PMMA particles showed lower polymerization rates than the linear ones during particle growth.
However, at high CUA concentrations (about 10 wt%), bimodal distributions were observed. This was attributed to the high crosslinking
density of the primary particle surfaces. Therefore, monomer diffusion toward the polymer phase was restricted, resulting
in more favorable secondary nucleation in the medium.
Received: 12 May 1998 Accepted: 19 August 1998 相似文献
5.
Characteristics of xenon-lamp pumped pyrromethene 567-doped dye laser based on polymethylmethacrylater 下载免费PDF全文
The solid-state medium containing pyrromethene 567 (PM567) in a polymethylmethacrylate polymer host is shown to lase under the flash lamp excitation. The experimental setup is an ordinary industrial product without special design. The bulk transmission losses, the output energy, and the other lasing properties are compared. The medium with the lowest transmission loss, measured to be 0.392 %/cm at 633 nm, gives a laser output of 130 mJ with a slope efficiency of 0.082%. 相似文献
6.
聚甲基丙烯酸甲酯型高分子染料的合成 总被引:2,自引:0,他引:2
高分子染料的合成研究起于60年代初[1].1973年,Marechal等实现了无色高分子材料与有色染料分子的化学键合[2~3].目前,高分子染料已广泛应用于化妆品、涂料、填料、食品等领域并开始探索在液晶显示、半导体材料、激光记录、非线性光学材料、亲和... 相似文献
7.
Qin Jiang Yuechun Du Lei Zhang Wangjing Ma Feng Yan Lu Zhang Sui Zhao 《Molecules (Basel, Switzerland)》2021,26(4)
The adsorption behaviors of extended anionic surfactants linear sodium dodecyl(polyoxyisopropene)4 sulfate (L-C12PO4S), branched sodium dodecyl(polyoxyisopropene)4 sulfate (G-C12PO4S), and branched sodium hexadecyl(polyoxyisopropene)4 sulfate (G-C16PO4S) on polymethylmethacrylate (PMMA) surface have been studied. The effect of branched alkyl chain on the wettability of the PMMA surface has been explored. To obtain the adsorption parameters such as the adhesional tension and PMMA-solution interfacial tension, the surface tension and contact angles were measured. The experimental results demonstrate that the special properties of polyoxypropene (PO) groups improve the polar interactions and allow the extended surfactant molecules to gradually adsorb on the PMMA surface by polar heads. Therefore, the hydrophobic chains will point to water and the solid surface is modified to be hydrophobic. Besides, the adsorption amounts of the three extended anionic surfactants at the PMMA–liquid interface are all about 1/3 of those at the air–liquid interface before the critical micelle concentration (CMC). However, these extended surfactants will transform their original adsorption behavior after CMC. The surfactant molecules will interact with the PMMA surface with the hydrophilic heads towards water and are prone to form aggregations at the PMMA–liquid interface. Therefore, the PMMA surface will be more hydrophilic after CMC. In the three surfactants, the branched G-C16PO4S with two long alkyl chains exhibits the strongest hydrophobic modification capacity. The linear L-C12PO4S is more likely to densely adsorb at the PMMA–liquid interface than the branched surfactants, thus L-C12PO4S possesses the strongest hydrophilic modification ability and shows smaller contact angles on PMMA surface at high concentrations. 相似文献
8.
A highly sensitive optical humidity probe based on reflectance measurements has been developed using Nafion®-crystal violet (CV) films. This sensor can be used to calibrate relative humidity (RH) in the range 0-0.25% with a detection limit (blank signal + 3σb, where σb = the standard deviation (S.D.) of the blank signal) of 0.018% RH (∼4.37 ppm) and exhibited low hysteresis. The sensor films were fully reversible in dry nitrogen and reversal times were shown to be dependent on exposure time and % RH. The response to 1% RH was highly reproducible (S.D. = 1.67%, number of samples (n) = 5). Hydrogen chloride gas did not interfere with the response of the sensor to RH but did reduce sensor reversal times. This sensor displayed sufficient sensitivity that it could be used to detect ppm levels of moisture in process gases such as nitrogen and HCl. 相似文献
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10.
通过含乙烯键的三联吡啶单体与甲基丙烯甲酯单体的共聚,制备了含配体的线性共聚物(P(MMA-co-TPY))。该共聚物继续与环金属铱二氯桥中间体反应,最终制备出含环金属铱配合物的高分子材料P(MMA-co-TPYIr)。用傅里叶变换红外光谱(FTIR)表征了材料的结构,并用紫外-可见光谱仪、荧光光谱仪研究了材料的光物理性能,最后研究了材料在溶液中的氧气传感性能。结果表明,环金属铱配合物已共价连接到高分子链上,固态下为纯红光发射,波长为638 nm,量子效率为0.035。该材料表现出了较好的氧气传感性能,并且在DMF中的效果最好,纯氮气和纯氧气氛围下的发光强度比为6,氧气检测限能达到0.34%。 相似文献