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1.
The studies allowed developing an accessible method of synthesis of a highly permeable α-oxide copolymer of wood by emulsion graft copolymerization with the reactive monomer glycidyl methacrylate and establishing the optimum conditions for conducting the process. In modification of a natural polymer with GMA with a concentration of 10% for 60 min at 80 °C in the presence of the Fe2+—H2O2 initiating redox system with a 2.52 mg/g iron ion content of 0.017%, almost quantitative conversion of the monomer and a high degree of grafting efficacy was attained. The mass fraction of PGMA in the fibre phase is 88–90% and the EN is 19–21%. Translated from Khimicheskie Volokna, No. 5, pp. 18–22, September–October, 2008. 相似文献
2.
Unsensitized, photoinitiated polymerization reactions of glycidyl methacrylate from solutions of water and water–methanol with cotton cellulose fabrics were investigated. When several layers of cotton fabrics were immersed in solutions of glycidyl methacrylate and only the surface layer was exposed to light, polymerization reactions were initiated in this layer and also initiated in inner layers of fabrics, probably by chain transfer reactions. Photoinitiated (350 nm, 24 W, 34 min) polymerizations of glycidyl methacrylate (7.5 vol-%) from water (43 vol-%)–methanol (57 vol-%) with cotton fabrics in one-, three-, and six-layered configurations were: one-layered, 32% polymer; three-layered, 30%, 27%, and 25% polymer; and six-layered, 29%, 25%, 22%, 20%, 14%, and 11% polymer. Electron-microscopic examination of the distribution of poly(glycidyl methacrylate) within the cotton fibrous structure showed that polymer was distributed throughout the cross section of the fiber. At the surface of the fibers, the polymer tended to be more concentrated than within the cross section of the fibers and to encapsulate them. Photoinitiated polymerization reactivities of several vinyl monomers from solution with cotton cellulose fabrics were compared with those of glycidyl methacrylate as follows: methyl methacrylate > glycidyl methacrylate > diacetone acrylamide > 1,3-butylene dimethacrylate > methacrylic acid > acrylonitrile > divinylbenzene. 相似文献
3.
The kinetics of the bulk thermal polymerization of phenyl glycidyl ether induced by trimethoxyboroxine were investigated. Infrared absorption spectroscopy and gel permeation chromatography were used to follow the course of polymerization, while proton and boron-11 NMR spectroscopy were used to support the kinetic model developed. The postulated mechanism involves a fast-initiated, nonstationary cationic polymerization with five elementary steps, including spontaneous and monomer transfer as well as a termination reaction. The trimethoxyboroxine was found to be incorporated into the structure of the cured polymer. The polymerization was followed at several temperatures and with several ratios of initial concentrations of trimethoxyboroxine to phenyl glycidyl ether. 相似文献
4.
Rubber wood was impregnated with styrene and glycidyl methacrylate (GMA) as the crosslinking monomer. Polymerization was accomplished by catalyst heat treatment. Compressive strength both in parallel and perpendicular to fiber directions was measured and improvement was observed for wood polymer composites. Bending strength in terms of Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) was measured and found improved on treatment over the untreated wood samples. Hardness for treated wood was also improved. Dynamic Mechanical Analysis (DMA) indicated an increase in interaction between wood, styrene, and GMA. Biodegradation of the treated and untreated wood samples was also determined and found to be improved on treatment. Scanning electron microscopy (SEM) study showed the wood polymer interaction. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers 相似文献
5.
Jason A. Payne Angela Strojny Lorraine F. Francis William W. Gerberich 《Polymer Engineering and Science》1998,38(9):1529-1535
A dynamic mechanical analyzer equipped with a diamond indenter tip was used to measure the elastic modulus of polymeric coatings as well as various bulk materials. A fabricated indenter probe was used to indent bulk samples of aluminum and fused quartz, as well as gelatin and polystyrene films in order to compare the micron-level indentation measurements with sub-micron (nanoindentation) techniques. The measured moduli were in agreement for ductile materials and thick films (>20 μm), but limited displacement resolution, material cracking, and hydrostatic pressure effects led to diverging values for thinner coatings and more brittle materials. 相似文献
6.
Technetium-99 comprises a significant health risk, since edible plants can bioaccumulate and convert it to more lipophilic
species that cannot be excreted through urine. Batch kinetics of pertechnetate removal from aqueous solutions by two samples
of crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) functionalized with diethylene triamine (PGME-deta) was investigated at the optimum pH value
of 3.0, and the initial solution activity of 325 MBq dm−3. PGME-deta was characterized by elemental analysis, mercury intrusion porosimetry, and scanning electron microscopy. Five
kinetic models (pseudo-first, pseudo-second order, Elovich, Bangham, and intraparticle diffusion) were used to determine the
best-fit equation for pertechnetate sorption. After 24 h, PGME-deta samples sorbed more than 98% of pertechnetate present,
with maximum sorption capacity of 25.5 MBq g−1, showing good potential for remediation of slightly contaminated groundwater. 相似文献
7.
The kinetics of the grafting polymerization of glycidyl methacrylate (GMA) onto leather were studied with chemical initiation systems. The results showed that the rate of grafting of GMA onto leather was dependent on different rates in the chemical initiation systems; for ammonium persulfate (AmPS)/acetone sodium bisulfite (ASBS), potassium persulfate (PPS)/ASBS, and sodium persulfate (SPS)/ASBS, the powers were 1.06, 0.48, and 0.43 and 0.63, 0.46, and 0.43, respectively, with respect to the concentration of the emulsifier sodium dodecyl sulfate, whereas the powers were 1.41, 0.70, and 0.81, respectively, with respect to the monomer concentration. The apparent activation energy was calculated for each initiation system and was found to be 180.8, 361.63, and 542.45 kcal for the AmPS/ASBS, PPS/ASBS, and SPS/ASBS systems, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
8.
Conclusions -- The special features of the graft polymerization of glycidyl methacrylate to polycaproamide fibre have been discovered. An anomalous effect of the copper compound and of hydrogen peroxide in the composition of the redox system on the rate of graft polymerization of glycidyl methacrylate has been found.-- The graft polymerization in the presence of the redox system Cuc-H2O2 which has been examined is characterized by a high rate and high monomer conversion and takes place essentially without formation of homopolymer.-- The relationships which have been found indicate a high efficiency and an ecological cleanness of the graft polymerization process at hand.Moscow State Textile Academy. Translated from Khimicheskie Volokna, No. 5, pp. 14–16, September–October, 1992. 相似文献
9.
10.
Kyu-Suk Hwang Young-Sik Son Sang-Wook Park Dae-Won Park Kwang Joong Oh 《Journal of Industrial and Engineering Chemistry》2009,15(6):854-859
An ionic liquid (THA-CP-MS41), trihexylamine-immobilized on chloropropyl-functionalized MCM41, was synthesized by a grafting technique through a co-condensation method and used as a catalyst in the reaction of carbon dioxide with glycidyl methacrylate (GMA). CO2 was absorbed into the heterogeneous system of the GMA solution and dispersed with solid particles of the catalyst in a batch stirred tank with a plane gas–liquid interface at 101.3 kPa. The absorption of CO2 was analyzed using the mass transfer mechanism accompanied by chemical reactions based on the film theory. The proposed model fits the measured data of the enhancement factor to obtain the reaction rate constants.Solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, and dimethyl sulfoxide influenced reaction rate constants. 相似文献
11.
A comparative investigation of the conventional and microwaves kinetics of methyl methacrylate (MMA) polymerization was performed. A method for determining the increase of the reaction rate in the microwave field (β) was presented. It was found that at all of the investigated temperatures and powers the polymerization rates increased in the presence of microwave energy by up to 8.9 times compared with conventional polymerization. Isothermal kinetics of the conventional MMA polymerization was investigated and its parameters were determined using isoconversion method. It was found that the calculated kinetics parameters changes complexly with degree of MMA conversion (α) and are in the mutual linear functional relationship, which is so called “compensation effect.” The complex changes of the kinetics parameters with α are explained with the postulated model for the mechanism of the MMA polymerization. The kinetics of the MMA polymerization under the microwave field (MWF) with different input power was investigated and its parameters were determined on the basis of the conversion‐temperature curves and Arrhenius equation. The values of the kinetics parameters for MMA polymerization in the MWF are dependent on α and are from 1.2 to 12 times lower than that for conventional MMA polymerization. A new method for the determination of activation energy (Ea) of the investigated process in the MWF was described. Decreased Ea value of the polymerization process in the MWF compared with the conventional polymerization is explained with the formation of the nonequilibrium energetic distribution of the reactants due to the rapid transfer of energy in the reaction system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1775–1782, 2007 相似文献
12.
Yongjun Chen E. T. Kang K. G. Neoh Yan Zhang K. L. Tan 《Polymer Engineering and Science》2002,42(6):1181-1196
Modification of argon plasma-pretreated Si(100) surfaces via plasma polymerization of glycidyl methacrylate(GMA), followed by reactive coupling of the epoxide groups of the plasma deposited GMA chains with aniline, and finally by oxidative graft polymerization of aniline was carried out. An alternative approach involved the modification of the argon plasma-pretreated Si(100) surfaces via plasma polymerization of glycidyl methacrylate(GMA), followed by direct oxidative graft polymerization of aniline and thermal curing. The compositions and chemical states of the modified Si surfaces were characterized by X-ray photoelectron spectroscopy (XPS). The two methods of surface modification of the Si(100) surfaces produced similar results. The protonation-deprotonation behavior, the interconvertible intrinsic redox states, and the metal reduction behavior (the electroless plating of Pd from the Pd(II) ion solution) of the grafted polyaniline (PANI) chains on the Si(100) surface were grossly similar to those of the PANI homopolymer. The coupling of PANI to the covalently tethered GMA chains on the Si(100) surface was suggested by the cohesive failure inside the epoxy adhesive that was applied to the modified Si surface in an attempt to peel off the PANI layer from the GMA plasma-polymerized Si (GMA-pp-Si) substrate. 相似文献
13.
Acrylonitrile (AN), methyl methacrylate (MMA), allyl glycidyl ether (AGE), AGE + AN monomer, AGE + MMA monomer, and monomer mixtures were used to conserve and consolidate beechwood. After the impregnation of these monomer mixtures in the wood, polymerization was accomplished by gamma irradiation. The fine structures of wood + polymer(copolymer) composites were investigated by scanning electron microscopy (SEM). The copolymer obtained from AGE + MMA monomer mixtures showed the optimum compatibility with the wood. The compressive strength and Brinell hardness numbers determined for untreated and treated wood samples indicated that the mechanical strength was greater in wood + polymer(copolymer) composites than in untreated wood and was greatest in the samples containing AGE + AN and AGE + MMA copolymers. All monomer couples used in this study increased the mechanical strength of the wood and protected the samples against aging. AGE + MMA copolymers were the most effective in protecting the wood against various environmental attacks. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1515–1523, 1999 相似文献
14.
A series of poly(methyl methacrylate) (PMMA) nanocomposites were synthesized using free radical polymerization in bulk, by addition of 1 vol% of oxide nanoparticles (silica, alumina, and titania), differing in the nature and type. The influence of nanofiller presence on the kinetics of methyl methacrylate (MMA) free radical polymerization was investigated. For this purpose, the kinetic model that includes the contribution from the first‐order reaction and the autoacceleration was applied on data obtained following the isothermal polymerization at 70°C by differential scanning calorimetry (DSC). The effect of the size and the surface nature of nanofillers on the interfacial layer thickness (d), as well as the influence of d on the glass transition temperature (Tg) of PMMA hybrid materials was studied. It was found that hydrophilic particles accelerated the initiator decomposition and affected the monomer polymerization on the surface, which caused the formation of thicker interfacial layer compared to the one around hydrophobic fillers. The addition of smaller nanoparticles size decreased the glass transition temperature of pure poly(methyl metacrylate). The linear increase of PMMA Tg value with increasing the polymeric interfacial layer was determined. The Tg values of pure PMMA and PMMA nanocomposite with d of 1.4 nm were estimated to be the same. POLYM. COMPOS. 34:1342–1348, 2013. © 2013 Society of Plastics Engineers 相似文献
15.
Hyperbranched polymers were produced using glycidyl methacrylate (GMA)/Cp2TiCl2/Zn as self-condensing vinyl polymerization (SCVP) system. The polymerization is firstly initiated by the epoxide radical ring opening catalyzed by Cp2Ti(III)Cl generated in situ via the reaction of Cp2TiCl2 with Zn. By optimizing the molar ratio of the SCVP inimer (GMA) to the mediator (Cp2Ti(III)Cl), the active propagation chains are reversibly transformed to the dormant species and the cross-linking does not occur until a higher level of monomer conversion (ca. 80%). We detail this facile one-step polymerization technique to prepare highly branched polymers with a multiplicity of particular end reactive functionalities including Ti alkoxide, hydroxyl and vinyl functional groups, which differs from most previously reported SCVP systems. 相似文献
16.
Poly(methylmethacrylate) (PMMA)/montmorillonite (MMT) nanocomposites were prepared by in situ suspension polymerization. MMT was previously organically modified by different modification agents [dioctadecyl dimethyl ammonium chloride (DODAC) and methacrylatoethyltrimethyl ammonium chloride (MTC)] and different modification method (cation‐exchange reaction and grafting reaction), ultimately giving rise to five kinds of organomodified MMT (OMMT). The structure of the OMMT was studied by Wide angle X‐ray diffraction (WAXD) and Fourier transform infrared spectroscopy (FTIR). Meanwhile, the structure of the PMMA/MMT nanocomposites microspheres was also investigated by WAXD. The molecular weight of the polymers extracted from PMMA/MMT nanocomposites was measured by gel permeation chromatograph (GPC). Finally, the mechanical properties of these PMMA/MMT nanocomposites were studied in detail. It was found that large interlayer spacing (d001) of OMMT could not entirely ensure an exfoliated structure of resultant PMMA/MMT nanocomposites, while OMMT with relative small d001 could still yield exfoliated structure as long as the compatibility between OMMT and polymer matrix was favorable. In addition, the results of mechanical investigation indicated that the compatibility between OMMT and PMMA matrix turned out to be the dominant factor deciding the final mechanical properties of PMMA/MMT nanocomposites. POLYM. COMPOS., 37:1705–1714, 2016. © 2014 Society of Plastics Engineers 相似文献
17.
Summary The plasma graft polymerization of glycidyl methacrylate (GMA) was investigated to obtain hydrophilic surface. The combination
of the argon plasma and GMA vapor exposures leaded to graft polymerization of GMA at the surface of polypropylene films. This
graft polymerization was initiated by the argon plasma exposure for 2 min, and was accomplished with the GMA vapor exposure
for 2 min. The GMA graft polymerization made polypropyrene surface hydrophilic. The surface energy was 55.8 mJ/m2. The hydrophilicity introduced by the GMA graft polymerization remained for at least 3 weeks. The graft polymerization of
hydrophilic monomers was a good means of hydrophilic surface modification. 相似文献
18.
Surface modification of high‐density polyethylene (HDPE) surfaces by plasma polymerization of glycidyl methacrylate (GMA) (the pp‐GMA‐HDPE surfaces), in the absence and presence of Ar plasma pre‐activation of the HDPE substrates, was carried out to enhance the adhesion of the polymer with evaporated copper. THe FTIR and X‐ray photoelectron spectroscopy (XPS) results suggested that the epoxide functional groups on the pp‐GMA‐HDPE surfaces had been preserved to various extents, depending on the RF power used during plasma polymerization. Ar plasma pre‐activation of the HDPE surface led to the strong interaction of the pp‐GMA layer with the HDPE substrate. GMA plasma polymerization at low RF powers and in the presence of Ar plasma pre‐activation was shown to be an effective method for enhancing the adhesion of HDPE with the evaporated Cu. An optimum adhesion strength of about 16 N/cm was achieved between the evaporated Cu and the pp‐GMA‐HDPE surface prepared by plasma polymerization of GMA at 5 W, 100 Pa, 20 sccm for 5 s on the HDPE surface pre‐activated by Ar plasma at 35 W, 100 Pa 20 sccm for 20 s. The adhesion enhancement of the Cu/pp‐GMA‐HDPE assemblies in the presence of Ar plasma pre‐activation of the HDPE substrate was attributed to the covalent bonding of the plasma‐polymerized GMA (pp‐GMA) layer with the HDPE surface, the preservation of the epoxide functional groups in the pp‐GMA layer, and the spatial interactions of pp‐GMA chains with the evaporated Cu matrix. 相似文献
19.
The homogeneous reverse atom transfer radical polymerization (reverse ATRP) of glycidyl methacrylate (GMA) was carried out in bulk, using 2,2′-azobisisobutyronitrile (AIBN) as the initiator and N,N-n-butyldithiocarbamate copper (Cu(SC(S)N(C4H9)2)2) as the catalyst. The polymerization showed typical controlled/‘living’ polymerization behavior, i.e. first-order kinetics, well-controlled molecular weight (Mn) and narrow molecular weight distribution (Mw/Mn). 1H NMR and IR spectra showed that the pendant epoxy groups in PGMA polymer remained intact throughout the polymerization of GMA. A phosphorated PGMA (PPGMA) polymer was obtained by phosphonation reaction of the pendant epoxy groups in PGMA with diphenylphosphinic chloride (DPPC). Thermal behavior of the PPGMA was studied by TG and DTG. A major DTG peak at 340 °C was observed for the PPGMA. 相似文献
20.
Jen-taut Yeh Chi-hui Tsou Ya-ming Li Han-wen Xiao Chin-san Wu Wan-lan Chai Yu-Ching Lai Chuen-Kai Wang 《Journal of Polymer Research》2012,19(2):9766-14
The Fourier transform infrared results suggest that the carboxylic acid groups of poly(lactic acid) (PLA) molecules react with the epoxy groups of molecules of Ethylene Glycidyl Methacrylate Copolymer (EGMC) during the reactive extrusion processes of PLAxEGMCy specimens. The tensile and tear strength values of PLAxEGMCy blown-film specimens in machine and transverse directions improve significantly, and reach their maximal values as their EGMC contents approach an optimum value of 6 wt.%. The melt shear viscosity values of PLAxEGMCy resins, measured at varying shear rates, are significantly higher than those of the PLA resin, and increase consistently with their EGMC contents. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) of PLA and PLAxEGMCy specimens reveal that the percentage crystallinity, peak melting temperature, and onset re-crystallization temperature values of PLAxEGMCy specimens reduce gradually as their EGMC contents increase. In contrast, the glass transition temperatures of PLAxEGMCy specimens increase gradually in conjunction with their EGMC contents. Demarcated porous morphology with several connected fungi-decomposed cavities was found on the surfaces of the PLAxEGMCy specimens after being buried for specific amounts of time, in which the sizes of the fungi-decomposed cavities found on the surfaces of buried PLAxEGMCy specimens reduce significantly as their EGMC contents increase. Further DMA and morphological analysis of PLAxEGMCy specimens reveal that the EGMC molecules are compatible with PLA molecules at EGMC contents equal to or less than 2 wt.% because no phase-separated EGMC droplets and tan δ transitions were found on fracture surfaces and tan δ curves of PLAxEGMCy specimens, respectively. The possible reasons for these remarkable properties of the PLA/EGMC specimens are proposed in this study. 相似文献