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1.
Summary The temperature dependence of the second virial coefficient and intrinsic viscosity of statistical copolymers of methyl methacrylate and methacrylic acid in 2-ethoxyethanol was investigated. It was found that the -temperatures of copolymers are outside the temperature range given by the -values for poly(methacrylic acid) and poly(methyl methacrylate). Their dependence on the copolymer composition has a discontinuity. Simple theoretical considerations have shown that this behaviour may be expected with copolymers composed of monomer units dissolving, respectively, with absorption and evolution of heat. 相似文献
2.
Hydrophobic-hydrolysable copolymers consisting of methyl methacrylate (MMA) and tert-butyldimethylsilyl methacrylate (TBDMSMA) have been synthesized for the first time by Reversible Addition-Fragmentation chain Transfer (RAFT) polymerization technique using cumyl dithiobenzoate (CDB) and cyanoisopropyl dithiobenzoate (CPDB) as chain transfer agents (CTAs). The monomer reactivity ratios for TBDMSMA (r1 = 1.40 ± 0.03) and MMA (r2 = 1.08 ± 0.03) have been determined using a non-linear least-squares fitting method. Well-defined random copolymers PMMA-co-PTBDMSMA have been prepared. Then, the versatility of the RAFT process to synthesize silylated block copolymers with controlled molecular weights and low polydispersities has been demonstrated using two strategies: the synthesis of PMMA-SC(S)Ph or PTBDMSMA-SC(S)Ph as macro-chain transfer agent (macro-CTA) for use in a two step method or an one-pot method which consists in the successive addition of the two monomers. Diblock copolymers with narrow molecular weight distributions (PDI < 1.2) were obtained from the one-pot method with number-average molecular weight values within the range 10,000-22,000 g mol−1. 相似文献
3.
Summary An investigation is presented of the preparation and characterization of poly(vinyl alcohol-co-methyl methacrylate) copolymers which can be used for the preparation of novel membranes. These polymers were prepared by copolymerization of vinyl acetate and methyl methacrylate by -irradiation, followed by methanolysis of the produced copolymers. IR and 1H-NMR studies established the structure of the copolymers.On sabbatical leave from the Department of Chemical Engineering, Sung Kyun Kwan University, Suwon 170-00, Republic of Korea. 相似文献
4.
J. A. Waterman G. E. la Heij H. van Hoorn 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1967,17(5):121-125
Methyl methacrylate has been grafted on artificial isoprene rubber (IR) latex, with use of redox initiation. The properties of latices containing up to 40 phr 1 Parts per hundred parts of rubber. methyl methacrylate (MMA) as well as solid products containing up to 80 phr of this compound were studied. Compared with ungrafted IR latex with the same solids content, the grafted IR latices had a lower viscosity, owing to their particle size being larger. Vulcanised films obtained from the grafted latices showed a considerably higher modulus, particularly at large deformations, than those based on IR or blends of IR with polymethyl methacrylate. by incorporation of certain reinforcing white fillers in the MMA-grafted IR latices, a further increase in the modulus of the latex films was effected. 相似文献
5.
A novel amine methacrylate monomer trimethylolpropane trimethacrylate–piperazine–ethyleneglycol dimethacrylate (TMPTMA‐PPZ‐EGDMA) was synthesized by amination of trimethylolpropane trimethacrylate (TMPTMA) with excess of piperazine (PPZ) followed by reaction with ethyleneglycol dimethacrylate (EGDMA). Copolymerization of TMPTMA‐PPZ‐EGDMA with 2‐hydroxyethyl methacrylate (HEMA) was carried out by free radical polymerization using ammonium persulfate (APS) and N,N,N′,N′‐tetramethyl ethylenediamine (TEMED) as a redox initiator. The copolymers obtained were then quaternized with 1‐iodooctane. The monomers were characterized by FTIR and 1H NMR spectral studies. The molecular weights and polydispersity values of the monomers were determined with gel permeation chromatography. Quaternized copolymers containing more than 20% amine methacrylate monomer showed microporosity in the range of 9.9–10.4 μm. The antibacterial activity of the quaternized copolymers against Escherichia coli and Staphylococcus aureus was studied using UV–vis spectrophotometer and scanning electron microscopy. Quaternized copolymers showed broad‐spectrum contact‐killing antibacterial properties without releasing any active agent as checked by iodide selective ion meter. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
6.
In the first step of this study, 2-[(methoxy-1,3-benzothiazole-2-yl)amino]-2-oxoethyl methacrylate (MBAOM) monomer was synthesized and characterized. Then, a series copolymers were obtained by free-radical copolymerization method of MBAOM and glycidyl methacrylate, which is a commercial monomer at 65°C in 1,4-dioxane solvent. Structural characterizations of synthesized monomer and copolymers were carried out using Fourier transform infrared spectrophotometer and nuclear magnetic resonance spectroscopy (1H and 13C-NMR) instruments. The composition of the copolymers was estimated by elemental analysis. The thermal behaviors of all the polymers have been investigated using the differential scanning calorimetry and the thermogravimetric analysis. A kinetic study of the thermal decomposition of copolymers was investigated using thermogravimetric analyzer with non-isothermal methods selected for analyzing solid-state kinetics data. The activation energy (Ea) values were calculated via Kissinger and Ozawa models in a period of α = 0.10–0.80. Photostability of the copolymers was investigated. Also, the biological activity of the copolymers against different bacterial and fungal species has been investigated. 相似文献
7.
Well‐defined methyl methacrylate (MMA) and 2‐(trimethylsiloxy)ethyl methacrylate (Pro‐HEMA) copolymers were prepared by atom‐transfer radical polymerization(ATRP), using CuCl/2,2′‐bipyridine as catalytic system and p‐toluenesulfonyl chloride as initiator. ATRP process of MMA and Pro‐HEMA was monitored by 1H NMR, and the kinetic curves of the MMA/Pro‐HEMA copolymerization were plotted in terms of the 1H NMR data. At low content of Pro‐HEMA in the feed composition, the copolymerization can be well controlled with the molecular weight, polydispersity and the monomer distribution in the copolymer chain. With the increase of Pro‐HEMA content in the feed mixture, the composition of the final copolymer deviates from the composition of the feed mixture gradually, and gradient copolymers of MMA/Pro‐HEMA can be obtained. Through the hydrolysis process, well‐defined copolymers of MMA/HEMA were obtained from poly(MMA/Pro‐HEMA). Copyright © 2003 Society of Chemical Industry 相似文献
8.
Anna B. Wjcik 《应用聚合物科学杂志》1985,30(2):781-788
Porous bead copolymers of di(methacryloyloxymethyl)naphthalene and methyl methacrylate have been synthesized using a mixture of isooctane and toluene as a diluent of the monomer system. The copolymers obtained exhibit similar specific surface areas and enhanced specific pore volume as compared to those prepared in the presence of dodecane and toluene. Their submicroscopic structure is visualized as first-order organization of microglobules similarly to PPS-type styrene–divinylbenzene copolymers. 相似文献
9.
A novel perfluorinated acrylic monomer 3,5‐bis(perfluorobenzyloxy)benzyl acrylate (FM) with perfluorinated aromatic units was synthesized with 3,5‐bis(perfluorobenzyl)oxybenzyl alcohol, acryloyl chloride, and triethylamine. Copolymers of FM monomer with methyl methacrylate (MMA) were prepared via free‐radical polymerization at 80°C in toluene with 2,2′‐azobisisobutyronitrile as the initiator. The obtained copolymers were characterized by 1H‐NMR and gel permeation chromatography. The monomer reactivity ratios for the monomer pair were calculated with the extended Kelen–Tüdos method. The reactivity ratios were found to be r1 = 0.38 for FM, r2 = 1.11 for MMA, and r1r2 < 1 for the pair FM–MMA. This shows that the system proceeded as random copolymerization. The thermal behavior of the copolymers was investigated by thermogravimetric analysis and differential scanning calorimetry (DSC). The copolymers had only one glass‐transition temperature, which changed from 46 to 78°C depending on the copolymer composition. Melting endotherms were not observed in the DSC traces; this indicated that all of the copolymers were completely amorphous. Copolymer films were prepared by spin coating, and contact angle measurements of water and ethylene glycol on the films indicated a high degree of hydrophobicity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
10.
Summary Poly(methyl methacrylate)-block-polysulfide-block-poly(methyl methacrylate) copolymers were synthesized for the first time through a new method involving the free radical
polymerization of MMA in the presence of a thiocol oligomer as a chain transfer agent, followed by chemical oxidation of the
remaining SH end-groups. The chain transfer constant of the SH end-groups of the thiocol was estimated from the rate of consumption
of the thiol groups versus the rate of consumption of the monomer (CT=0.67). The triblock copolymers synthesized were characterized by SEC and 1H NMR measurements. 相似文献
11.
A novel quaternary amine methacrylate monomer (QAMA) was synthesized by amination of dimethacrylate with piperazine followed by its quaternization using an alkyl iodide. Copolymerization of QAMA with 2‐hydroxyethyl methacrylate was carried out by free radical bulk polymerization technique at room temperature using ammonium persulfate and N,N,N′,N′‐tetramethyl ethylenediamine as a redox initiator. The monomer as well as copolymers was characterized by FTIR and 1H NMR spectral studies. Thermal and physical characteristics of copolymers of varying compositions of QAMA were evaluated by thermogravimetric analysis, differential calorimetry, contact angle and scanning electron microscopy. The antibacterial activity of the synthesized quaternary amine dimethacrylate copolymers against Escherichia coli and Staphylococcus aureus was studied by zone of inhibition and colony count method. QAMA copolymers showed broad‐spectrum contact killing antibacterial properties without releasing any active agent as checked by iodide‐selective ion meter. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1038–1044, 2006 相似文献
12.
Karl L. Wallisch 《应用聚合物科学杂志》1974,18(1):203-222
Pyrolysis gas chromatography can distinguish random from block copolymers of ethylacrylate and methyl methacrylate. The pyrograms depend on the pyrolytic temperature, the ratio of copolymerized monomers, the degree of conversion, and the method of polymerization. Larger amounts of ethyl methacrylate and methyl acrylate are formed on pyrolysis of random copolymers than of block copolymers. The presence of mixed dimers indicates random copolymerization. The sum of the percent recovery of ethyl alcohol and ethyl acrylate is fairly constant over a range of compositions and monomer sequence. Random copolymers produce less ethyl alcohol than ethyl acrylate on pyrolysis, while homopolymers and block copolymers produce more ethyl alcohol and less ethyl acrylate. In a set of random copolymers with different EA/MMA ratios, there is an increasing per cent recovery of EA monomer with decreasing EA in the copolymer, while ethyl alcohol shows the opposite behavior. The characteristic degradation patterns are thought to be governed by the availability of the tertiary hydrogen for abstraction by the alkoxy oxygen of a neighboring acrylate unit, the availability depending on the sequence distribution of acrylate/methacrylate molecules. 相似文献
13.
Three isomeric, linear, equimolar, amphiphilic ABC triblock copolymers comprising methyl methacrylate (MMA, nonionic hydrophobic), 2-(dimethylamino)ethyl methacrylate, (DMAEMA, ionizable hydrophilic) and hexa(ethylene glycol) methacrylate (HEGMA, nonionic hydrophilic) units (10 units in each block) were synthesized by group transfer polymerization (GTP). These were the three block sequence isomers, ABC, ACB and BAC. The corresponding random terpolymer was also prepared. The molecular weights and compositions of all the polymers were characterized by GPC and 1H NMR. Measurements of the hydrodynamic diameters and cloud points of the copolymers in aqueous solution suggest that the various distributions of monomer units in the four terpolymers (the three triblocks and the random) result in different supramolecular structures with different colloidal stabilities. 相似文献
14.
Methyl methacrylate/vinylidene chloride (M/V) copolymers of different monomer concentrations were prepared by photopolymerization using the uranyl ion as photosensitizer. The copolymer composition was determined by chlorine estimation of the copolymers. The complete assignment of the 13C{1H} NMR spectra of these copolymers is made by comparison with the spectra of poly(methyl methacrylate) and observing the changes in the intensities of the resonances with copolymer composition. The quaternary carbon of V- and M- center resonances were used for determining the sequence in terms of the distribution of V- and M- centered triads. The triad fractions thus obtained were compared with theoretically determined triad concentrations. The Monte Carlo simulation method was also used for estimating the copolymerization behavior. The variation of V- and M- centered triad concentrations was reported as a function of fractional conversions. The comonomer reactivity ratios, determined by both Kelen Tudos and nonlinear error in variables methods are rV = 0.26 ± 0.04 and rM = 2.88 ± 0.23. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 373–381, 1998 相似文献
15.
Miroslav Janata Antonín Sikora Petra Látalová Eva Čadová Vladimír Raus Libor Matějka Petr Vlček 《应用聚合物科学杂志》2013,128(6):4294-4301
Defined diblock and triblock copolymers composed of methyl methacrylate‐co‐glycidyl methacrylate block and 3‐{3,5,7,9,11,13,15‐hepta(2‐methylpropyl)‐pentacyclo[9.5.1.13,9.15,15.17,13]‐octasiloxan‐1‐yl}propyl methacrylate block(s), i.e., P(MMA‐co‐GMA)‐b‐PiBuPOSSMA and PiBuPOSSMA‐b‐P(MMA‐co‐GMA)‐b‐PiBuPOSSMA, were synthesized by atom transfer radical polymerization (ATRP). First, monofunctional and bifunctional P(MMA‐co‐GMA) copolymers were synthesized by ATRP. Subsequently, these copolymers were successfully used as macroinitiators for ATRP of POSS‐containing methacrylate monomer. The process showed high initiation efficiency of macroinitiators and led to products with low dispersity. The synthesized block copolymers were characterized by size exclusion chromatography, 1H‐NMR spectroscopy and their glass transition temperatures were determined by differential scanning calorimetry. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
16.
Homopolymers of 2-hydroxypropyl methacrylate (HPMA) and copolymers with acrylic acid (AA) were prepared in 1,4-dioxane. The reactivity ratios were determined to be rAA = 0.27 ± 0.04 and rHPMA = 2.2 ± 0.2. The alkaline hydrolysis by sodium hydroxide of the HPMA monomer and polymers showed that while the HPMA monomer hydrolyzed readily as expected for a low-molecular-weight carboxylic ester the HPMA homopolymer and water-soluble sodium acrylate (NaA) copolymers were extremely resistant to alkaline hydrolysis. The saponification reaction followed a second-order rate equation, being first order with respect to both HPMA and hydroxide ion concentration. The Arrhenius parameters, activation energy E and frequency factor A, for the alkaline hydrolysis of HPMA monomer in water were found to be E = 10.3 Kcal/mol and A = 1.5 × 108 L/mol min, and those for the NaA–HPMA copolymers in water were found to be E = 24 kcal/mol and A = 4 × 1012 L/mol min. The NaA–HPMA copolymers had a limiting extent of hydrolysis, ranging from 9–90% ester conversion. A sharp rate decrease at low conversion was noted during the HPMA homopolymer hydrolysis in 58/42 dimethyl sulfoxide/water, allowing the calculation of two distinct reaction rates. © 1992 John Wiley & Sons, Inc. 相似文献
17.
Osamu Nakagawa Nobutaka Fujimoto Takafumi Nishiura Tatsuki Kitayama Koichi Hatada 《Polymer Bulletin》1992,29(5):579-586
Summary Highly syndiotactic diblock and triblock copolymers comprising lauryl methacrylate (LMA) and methyl methacrylate (MMA) with narrow molecular weight distributions were prepared by the living anionic polymerization with t-C4H9Li/(C2H5)3Al in toluene at low temperature. The block copolymers were soluble in acetone which is a non-solvent for poly(lauryl methacrylate) (PLMA). 1HNMR and vapor pressure osmometric analyses of the block copolymers indicated the aggregation of the copolymer in acetone through the interaction between PLMA blocks. Stereocomplex formation between the triblock copolymer and isotactic poly(methyl methacrylate) (PMMA) took place more effectively in solution than in the solid state. 相似文献
18.
Copolymers of methyl methacrylate (MMA) and cardanyl methacrylate (CMA) were synthesized, characterized and their physico-mechanical properties were investigated. The benzoyl peroxide-initiated copolymerization was carried out by using different mole fractions of CMA (0.02–0.10) in the initial feed at 80°C. Structural characterization of copolymers was done using FTIR and 1H NMR spectroscopic techniques. The thermal stability of the copolymers was evaluated using dynamic thermogravimetry. Incorporation of CMA in the MMA backbone leads to an improvement in thermal stability. 相似文献
19.
Homopolymers and copolymers of styrene and butyl methacrylate were synthesized with different ratios by an emulsion polymerization technique with K2S2O8/NaHSO3 as the redox initiation system and sodium dodecyl sulfate as the emulsifier at 60°C for 3 h. The effects of different monomer ratios on the kinetics of emulsion polymerization and polymer viscosity were studied. These copolymers were applied to leather surfaces with a hand coater to a thickness of 18 μm. The effects of the coatings on the leather surfaces were evaluated through the measurement of physical and mechanical properties of coated and uncoated leather. IR spectra showed new bands characteristic of styrene and butyl methacrylate, which disappeared in the spectrum of uncoated leather. The physical and mechanical results showed that the water absorption content decreased with increasing styrene content, and the water vapor permeability of the coated leather was less than that of the uncoated leather; however, it was still in the acceptable range. The results indicated improvements in the tensile strength and elongation (%) for the coated leather with increases in the butyl methacrylate content. Thermogravimetric analysis showed characteristic improvements in the thermal stability of leather after the coating; its optimum stability was reached when the leather was coated with poly(styrene:butyl methacrylate) (1 : 1). Finally, scanning electron microscopy showed the full grain surface of the leather. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
20.
Ian R. Wilding Colin D. Melia Robert D. Short Martyn C. Davies Alan Brown 《应用聚合物科学杂志》1990,39(9):1827-1835
This study reports on the use of static secondary ion mass spectroscopy (SSIMS) to chemically characterize complex methacrylate copolymers used in the pharmaceutical industry for controlled drug delivery. Ions diagnostic of the component monomer residues were detected, which could be interpreted using a fragmentation model for alkylmethacrylate homopolymers proposed previously. This model is extended to include the SSIMS analysis of nitrogen-containing methacrylate copolymer residues. 相似文献