共查询到20条相似文献,搜索用时 15 毫秒
1.
Gregory B. Kharas Katherine Kim Kimberly C. Beinlich Sarah B. Benington Sarah K. Brennan Michelle Morales Norman E. Ruano Doo Y. Won Emanuel Adibu Kenneth Watson 《Polymer Bulletin》2000,45(4-5):351-357
Summary
Methyl 2-cyano-3-dihalophenyl-2-propenoates, R2C6H3CH=C(CN)CO2CH3 (R2= 2,4-difluoro, 2,5-difluoro, 2,6-difluoro, 3,4-difluoro, 3,5-difluoro, and 2-chloro-6-fluoro), were prepared by the piperidine
catalyzed Knoevenagel condensation of corresponding disubstituted benzaldehydes and methyl cyanoacetate. Novel copolymers
of the propenoates and styrene were prepared at equimolar monomer feed by solution copolymerization in the presence of a radical
initiator. The order of relative reactivity (1/r
1) was 2,5-difluoro (2.11) > 2,6-difluoro (1.84) > 3,5-difluoro (1.71) > 2,4-difluoro (1.4) > 3,4-difluoro (0.65) > 2-chloro-6-fluoro
(0.59). The copolymers were characterized by IR, 1H and 13C NMR, GPC, DSC and TGA. High glass transition temperatures of the copolymers compared that of polystyrene indicates a substantial
decrease in chain mobility of the copolymers due to the high dipolar character of the trisubstituted ethylene monomer unit.
Received: 12 June 2000/Revised version: 12 September 2000/Accepted: 12 September 2000 相似文献
2.
The triad monomer unit sequence distribution and the cis and trans linkage configurations at the cyclic citraconic anhydride units are quantitatively determined for the copolymers of citraconic
anhydride (α-methylmaleic anhydride) (CA) and styrene (ST) prepared with AIBN in CCl4 solutions at 50 °C. Semi-alternating copolymers are obtained for most feed compositions with rigidly alternating copolymers
being formed when CA in feed is more than 90%. Greater than 50% of the linkages at CA units are found to be in cis configuration in semi-alternating copolymers. This may be explained if the donor-acceptor complex formed between CA and ST
participates in the copolymerization.
Received: 14 November 1996/Revised: 5 March 1997/Accepted: 10 March 1997 相似文献
3.
Investigation on preparation and property of nano‐CaCO3/PP masterbatch modified by reactive monomers
Nano‐CaCO3/polypropylene (PP) masterbatch containing above 80 wt % nano‐CaCO3 was prepared by nano‐CaCO3 coated PP modified by reactive monomers. The chemical interaction, crystallization and melting behavior, thermal stability, morphology, and surface contact angle of masterbatch were investigated with IR, DSC, TEM, TGA, ESCA, and surface contact angle. The results indicated that nano‐CaCO3 was coated by PP graft copolymers in the masterbatch modified by reactive monomers. The graft ratio and crystallization and melting behavior of PP in the masterbatch depended on the type and content of reactive monomer. The crystallization temperatures of masterbatch modified by reactive monomer is methyl methacrylate > butyl acrylate > methyl acrylate ≈ mixture of acrylic acid and styrene > unmodified ≈ maleic anhydride ≈ acrylic acid > styrene. Modification by reactive monomer increased the thermal stability and surface contact angle of masterbatch. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3907–3914, 2006 相似文献
4.
Jatin N. Patel Mitul B. Dolia Kirit H. Patel Rajni M. Patel 《Journal of Polymer Research》2006,13(3):219-228
The methacrylate monomer 4-chloro-3‐methyl phenyl methacrylate (CMPM) was synthesized by reacting 4-chloro-3‐methyl phenol
with methacryloyl chloride. The homopolymer and various copolymers of CMPM with n-butyl methacrylate were synthesized by free-radical polymerization in toluene at 70°C using 2,2′-azobis(isobutyronitrile)
as the initiator. The CMPM monomer was characterized by Fourier transform IR and 1H-NMR studies. The copolymers were characterized by IR spectroscopy. The molecular weights (M
n and M
w) and the polydispersity index were obtained from gel permeation chromatography. The solubility and intrinsic viscosity of
the homopolymer and the copolymers are also discussed here. The copolymer composition obtained from UV spectra led to the
determination of reactivity ratios employing Fineman-Ross and Kelen-Tudos linearization methods. Thermogravimetric analyses
of the homopolymer and the copolymers were carried out under a nitrogen atmosphere. The homopolymer and the copolymers prepared
were tested for their antimicrobial activity against bacteria, fungi and yeasts. 相似文献
5.
A combination of coordination polymerization and atom transfer radical polymerization (ATRP) was applied to a novel synthesis of rod–brush block copolymers. The procedure included the following steps: (1) the monoesterification reaction of ethylene glycol with 2-bromoisobutyryl bromide (BIBB) yielded the bifunctional initiator monobromobutyryloxy ethylene glycol and (2) a trichlorocyclopentadienyl titanium (CpTiCl3; bifunctional initiator) catalyst was prepared from a mixture of CpTiCl3 and bifunctional initiator. The coordination polymerization of n-butyl isocyanate initiated by such a catalyst provided a well-defined macroinitiator, poly(n-butyl isocyanate)–bromine (PBIC–Br). (3) The ATRP method of 2-hydroxyethyl methacrylate initiated by PBIC–Br provided rod [poly(n-butyl isocyanate) (PBIC)]–coil [poly(2-hydroxyethyl methacrylate) (PHEMA)] block copolymers with a CuCl/CuCl2/2,2′-bipyridyl catalyst. (4) The esterfication of PBIC-block-PHEMA with BIBB yielded a block-type macroinitiator, and (5) ATRP of methyl methacrylate with a block-type macroinitiator provided rod–brush block copolymers. We found from the solution properties that such rod–brush block copolymers formed nanostructured macromolecules in solution. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
6.
Poly(vinyl chloride) (PVC) with pendent N,N‐diethyldithiocarbamate groups (PVC–SR) was prepared through the reaction of PVC with sodium N,N‐diethyldithiocarbamate (NaSR) in butanone and used as a photoinitiator for the grafting polymerization of three vinyl monomers [styrene (St), methyl methacrylate (MMA), and acrylamide (Am)]. The effects of ultraviolet (UV) irradiation time, PVC–SR amount, and the monomer amount on grafting and grafting efficiency were investigated. The results showed that PVC–SR could initiate the polymerization of three vinyl monomers effectively and obtained crosslinked copolymers. The grafting and grafting efficiency of styrene and methyl methacrylate were higher than those of acrylamide. The polymerization activity of three monomers was acrylamide > methyl methacrylate > styrene. By analyzing the UV spectrum of PVC–SR with a different irradiation time, it was confirmed that PVC–SR was dissociated mainly into macromolecular the sulfur radical PVC–S · and the small molecular carbon radical · C(S)N(C2H5)2; the grafting polymerization mechanism was discussed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2569–2574, 2000 相似文献
7.
Summary
An oligomer of the methyl acrylate unsaturated trimer bearing 2-carbomethoxy-2-propenyl ω-end group (M
n = 1300, M
w/M
n = 1.7, and functionality > 0.7) was copolymerized as a macromonomer (0.02 mol/L) with styrene (1.0 mol/L) in benzene at 60
°C. The amounts of monomer and macromonomer in the feed simultaneously decreased with increasing time to indicate copolymer
formation, and the macromonomer was found to be as reactive as styrene toward poly(styrene) radicals. The M
ns of the copolymers were 13900–22000 depending on conversion. No resonance due to the unsaturated <ω-end group bound to the
poly(styrene) chain was detected by 1H-NMR spectroscopy, indicating that no fragmentation of adduct radical of the end group to expel the poly(methyl acrylate
trimer) radical. Polymerization of ethyl methacrylate (1.0 mol/L) in the presence of the macromonomer (0.02 mol/L) resulted
in a mixture of the unreacted macromonomer and homopolymer of ethyl methacrylate. No end group bound to the poly(ethyl methacrylate)
was detected by 1H-NMR spectroscopy, excluding the possibility of addition fragmentation chain transfer to the macromonomer to expel an oligomer
radical of the methyl acrylate trimer. Addition of the poly(methacrylate) radical to the macromonomer is extremely slow under
the present conditions of copolymerization.
Received: 27 March 2003/Revised version: 30 April 2003/ Accepted: 30 April 2003
Correspondence to Bunichiro Yamada 相似文献
8.
Radical copolymerizations of N-vinyl-2-pyrrolidone (VP) with isostructural
analogs of maleic anhydride (MA), such as citraconic anhydride (CA) and N-substituted
maleimides [maleimide (MI), N-ethylmaleimide (EMI) and N-phenylmaleimide
(PhMI)] were studied. Compositions of copolymers synthesized in a wide range of monomer feed ratios were
determined by alkali titration (for anhydride copolymers), FTIR and 1H NMR spectroscopy
using 1495 and 630 cm-1 (for VP-MI), 1289 and 1225 cm-1
(for VP-EMI) and 1050 and 3067 cm-1 (for VP-PhMI) analytical bands and
integral areas of CH2 (pyrrolidone ring) and CH (MI), CH3
(EMI) and CH= (benzene ring in PhMI) groups, respectively. Electron-donor VP monomer was found to have
substantially different reactivities in the radical copolymerization with MA, CA and N-substituted
(H, C2H5 and phenyl) malemides as electron-acceptor comonomers.
Effects of H-bonding and N→O=C coordination on the monomer reactivity ratios were evaluated. Tendency
to alternation of the monomer pairs increases in the order of VP–MA > VP–CA > VP-MI
> VP-PhMI > VP-EMI. Structure-thermal property-relationship for the synthesized copolymers was
also studied. 相似文献
9.
The new cyclic carbonate monomer 2,4,8,10-tetraoxaspiro[5,5]undecane-3-one (DOXTC) was prepared in > 80% yield by the reaction of 1,3-dioxane-5,5-dimethanol with ethyl chloroformate in tetrahydrofuran (THF). DOXTC homopolymerization and copolymerizations with trimethylene carbonate (TMC) were carried out using aluminoxanes (methyl and isobutyl) as catalysts. The copolymer yields normally exceeded 90%. Carbon-13 (13C) nuclear magnetic resonance (NMR) at 62.5 MHz resolved copolymer dyad sequences. Comparison of the fraction of dyad sequences determined by 13C-NMR and calculated assuming a Bernoullian distribution showed that propagation statistics were approximately random for copolymerizations carried out at both 90 and 140°C. Studies by differential scanning calorimetry (DSC) showed that the DOXTC homopolymer, as well as the copolymers with high DOXTC content (FDOXTC to FTMC ≥7 : 3), were semicrystalline. The DOXTC homopolymer had a peak melting temperature of 202°C, enthalpy of fusion of 75 J/g, and a glass transition temperature of 36°C. For copolymers with FDOXTC to FTMC ≥ 9/1, crystallization exotherms were observed both during the second heating, as well as cooling (10°C/min) DSC scans. The relationship between the copolymer glass transition and composition was in agreement with that predicted by the Fox equation. Comparison of the wide-angle X-ray scattering (WAXS) patterns of the DOXTC homopolymer with FDOXTC to FTMC of 7 : 3 and 9 : 1 showed that the former sample had more pronounced and better resolved crystalline reflections. These results suggest that the DOXTC homopolymer has well-ordered crystalline domains and high sample crystallinity. By increasing the molar content of 1,3-dioxane side groups in DOXTC-TMC copolymers from 0 to 50%, the water uptake by the corresponding films was increased from 5.1 to 19% (w/w). © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 547–557, 1989 相似文献
10.
Poly(dimethylsiloxane)(PDMS)‐based triblock copolymers were successfully synthesized via atom transfer radical polymerization (ATRP) initiated with bis(bromoalkyl)‐terminated PDMS macroinitiator (Br‐PDMS‐Br). First, Br‐PDMS‐Br was prepared by reaction between the bis(hydroxyalkyl)‐terminated PDMS and 2‐bromo‐2‐methylpropionyl bromide. PSt‐b‐PDMS‐b‐PSt, PMMA‐b‐PDMS‐b‐PMMA and PMA‐b‐PDMS‐b‐PMA triblock copolymers were then synthesized via ATRP of styrene (St), methyl methacrylate (MMA) and methyl acrylate (MA), respectively, in the presence of Br‐PDMS‐Br as a macroinitiator and CuCl/PMDETA as a catalyst system at 80 oC. Triblock copolymers were characterized by FTIR, 1H‐NMR and GPC techniques. GPC results showed linear dependence of the number‐average molecular weight on the conversion as well as the narrow polydispersity indicies (PDI < 1.57) for the synthesized triblock copolymers which was lower than that of Br‐PDMS‐Br macroinitiator (PDI = 1.90), indicating the living/controlled characteristic of the reaction. Also, there was a very good agreement between the number‐average molecular weight calculated from 1HNMR spectra and that calculated theoretically. Results showed that resulting copolymers have two glass transition temperatures, indicating that triblock copolymers have microphase separated morphology. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
11.
Attempts to introduce a fluorine atom directly at the C-3 position of the triterpenoidal glycyrrhetic acid 1 by reacting the tosylate 2 with KF, or methyl glycyrrhetate 5 with Et2NCF2CHCIF, failed. The ring A olefin 3 and the rearrangement product 4 were obtained. The homoannular diene 7 was treated with NOF, but only nitroso-fluorine compounds 8, 9 were isolated. Nitrosyl fluoride was also reacted with olefin 3 . A difluoro compound 10 and the expected 2-keto-3α-fluoro compound 11 were obtained. The above two olefins were also reacted with bromine fluoride. Although the diene 7 gave only fluorine-free compounds 13, 14 , the expected fluoro-bromine compound 16 was obtained from 3 . When the 2β-fluoro-3α-bromo compound was treated with Bu3SnH, the bromine atom was replaced by hydrogen and the 2β-fluoro compound 17 was formed. 相似文献
12.
2-thiozyl methacrylamide (TMA) was synthesized by the reaction of 2-aminothiazole with either methacryloyl chloride or methacrylic acid in the presence of triethylamine and N, N′-dicyclohexylcarbodiimide, respectively. Binary copolymerization reactions of the prepared monomer with methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (BA) and tert-butylacrylate (t.BA) were performed in dimethylformamide at 65 ○C using 1 mol% azobisisobutyronitrile (AIBN) as initiator. The structure of the 2-thiozyl methacrylamide monomer and the prepared copolymers was investigated by IR and 1H NMR spectroscopy. The copolymer compositions were determined from sulphur analysis. Copolymerization parameters for each system were calculated by the Finemen–Ross and Kelen–Tüdös methods. The monomer reactivity ratios for the systems TMA-MA, TMA-EA, TMA-BA, and TMA-tBA were found to be r1=0.128, r2=0.740; r1=0.235, r2=0.420; r1=0.420, r2=0.330 and r1=1.690, r2=0.027, respectively. The reactivities of acrylic esters decrease as the alkyl group become bulkier. The average Q and e values for TMA were calculated from the monomer reactivity ratios determined in the present and previous studies. 相似文献
13.
Ye Lin Zhao Yumei Feng Zengguo Bai Ying Wu Feng 《Frontiers of Chemical Engineering in China》2007,1(4):343-348
An oxetane-derived monomer, 3-acryloyloxy-methyl-3′-methyloxetane (AMO) was prepared from the reaction of 3-hydromethyl-3-methyloxetane
with acryloyl chloride. The cationic ring-opening copolymerization of AMO with another oxetane-derived monomer, 3-(2-(2-(2-methoxyethylenoxy)ethylenoxy)ethylenoxy)-3′-methyloxetane
(MEMO) was conducted in CH2Cl2 solution using BF3 · OEt2/1,4-butanediol as a co-initiator. The resulting copolymers were characterized by FTIR, 1H NMR and Gel Permeation Chromatography (GPC) analyses, and it was found that the enchained ratio of AMO in the copolymers
is far lower than its feed ratio. They were crosslinked in situ via the radical polymerization of the vinyl group initiated by BPO after doping with lithium trifluoromethanesulfonimide
(LiTFSI) to give rise to tough polymeric electrolyte films. The ionic conductivity was measured at varying content of AMO
and different concentration of lithium salt LiTFSI by AC impedance, and a maximum ion conductivity of 1.44 × 10−5 S/cm at 30°C or 1.25 × 10−4 S/cm at 80°C was attained in the sample PAM 33 at the mole ratio of O: Li = 20. The DSC results indicated that T
g decreases with the increase of the proportion of AMO in the copolymer, well consistent with the ion conductivity trend. The
TGA (thermogravimetric analysis) measurement revealed that this kind of copolymer electrolytes is more thermostable than their
liquid counterparts.
__________
Translated from Transactions of Beijing Institute of Technology, 2006, 26(12): 1098–1103 [译自: 北京理工大学学报] 相似文献
14.
Tian‐Ying Guo Guang‐Liang Tang Guang‐Jie Hao Moud‐Dao Song Bang‐Hua Zhang 《应用聚合物科学杂志》2002,86(12):3078-3084
Different poly(methyl methacrylate/n‐butyl acrylate)/poly(n‐butyl acrylate/methyl methacrylate) [P(BA/MMA)/P(MMA/BA)] and poly(n‐butyl acrylate/methyl methacrylate)/polystyrene [P(BA/MMA)/PSt] core‐shell structured latexes were prepared by emulsifier‐free emulsion polymerization in the presence of hydrophilic monomer 3‐allyloxy‐2‐hydroxyl‐propanesulfonic salt (AHPS). The particle morphologies of the final latexes and dynamic mechanical properties of the copolymers from final latexes were investigated in detail. With the addition of AHPS, a latex of stable and high‐solid content (60 wt %) was prepared. The diameters of the latex particles are ~0.26 μm for the P(BA/MMA)/P(MMA/BA) system and 0.22–0.24 μm for the P(BA/MMA)/PSt system. All copolymers from the final latexes are two‐phase structure polymers, shown as two glass transition temperatures (Tgs) on dynamic mechanical analysis spectra. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3078–3084, 2002 相似文献
15.
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
16.
SUMMARY
SUMMARY
Copolymerization of propene and 1-hexene has been carried out in toluene at 30°C in the presence of homogeneous methylaluminoxane
(MAO)-activated 3 ansa-metallocenes, highly syndiospecific iPr(Cp)(Flu)ZrMe2 (
1 ), lower syndiospecific Et(Cp)(Flu)ZrMe2 (
2 ), and isospecific rac-(EBTHI)ZrMe2 (
3 ), in order to study the role of catalyst stereospecificity on comonomer incorporation. The incorporation of 1-hexene decreases
in the following order: highly syndiospecific
1 /MAO catalyst > lower syndiospecific
2 /MAO catalyst > isospecific
3 /MAO catalyst. All copolymer chains contain the comonomer in nearly random distribution. The copolymers produced by
1 /MAO and
3 /MAO catalysts were composed of uniform chains, but that by
2 /MAO was fractionated into many fractions in the solvent extraction. Considerable rate enhancements were recorded in the copolymerization
when the feed ratio of 1-hexene to propene is around 0.6 for all catalysts.
Received: 16 December 1997/Revised version: 9 February 1998/Accepted: 19 February 1998 相似文献
17.
AB amphiphilic comb-like block copolymers of poly(oligo[ethylene glycol] methyl ether methacrylate) and polydimethylsiloxane were synthesised with a methodology based on atom transfer radical polymerization (ATRP). The anionic ring opening polymerisation of hexamethylcyclotrisiloxane followed by reaction with 3-(chlorodimethylsilyl) propyl 2-bromo-2-methylpropanoate propyldimethylchlorosilane gave suitable macroinitiators for the ATRP of oligo[ethylene glycol] methyl ether methacrylate. The latter synthetic procedure was optimised by performing a number of syntheses varying the reaction solvent, catalytic complex and the temperature used. Copolymers with relatively high polydispersity indices (Mw/Mn>1.3) could be synthesised at room temperature by employing a Cu(I)Br:N,N,N′,N′,N″-pentamethyldiethylenetriamine complex in n-propanol with Cu(II)Br. The optimum reaction conditions employed a Cu(I)Cl:N-(n-propyl)-2-pyridyl(methanimine) complex with an n-propanol/water mixture or toluene as solvent at 90 °C. This gave block copolymers of the desired molecular weights and polydispersity indices of less than 1.1. The block copolymers were characterised with 1H NMR and 13C NMR spectroscopy and size exclusion chromatography. 相似文献
18.
Self-associating copolymers of methacrylic acid (MAA) with poly (ethylene glycol) monomethacrylate (PEGMA) were prepared by free radical copolymerization of MAA with PEGMA using dispersion polymerization in D2O, or solution polymerization in a 50/50 ethanol–D2O mixture. These copolymers have been studied as components of reversible hydrogels1 and in medical applications.2 In order to understand the relationship between the copolymer structure and its performance, it is important to determine the sequence distribution of the copolymer. The copolymer architecture is determined by the reactivity ratios and integrated instantaneous feed compositions. The reactivity ratios were determined using the first-order Markov method3 by running a series of reactions at various initial monomer ratios and determining the monomer incorporation into the copolymer as a function of time, via 1H nuclear magnetic resonance. The reactivity ratios for dispersion copolymerizations of MAA with PEGMA in water were determined to be r1 = 1.03 and r2 = 1.02, whereas solution copolymerization in 50/50 EtOH–H2O gave reactivity ratios of r1 = 2.0 and r2 = 3.6. These results show that the reactivity ratios and copolymer architecture are influenced by the solvent system. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1019–1025, 1998 相似文献
19.
Summary
Macromonomeric peroxy initiator, poly tetrahydrofuran (poly-THF=inimer) were synthesized via cationic polymerization of THF
by the mono- (t-BuBP) and tetra-bromo methyl benzoyl peroxides (BDBP)/ZnCl2 initiating system. The macromonomers were characterized by 1H-NMR, IR, and GPC techniques. Methyl methacrylate (MMA) polymerization initiated by poly-THF inimers at 80°C and different
times in bulk gave crosslinked poly-THF-b-polymethyl methacrylate block copolymers. Swelling ratios of the crosslinked block
copolymers obtained by taking in same amounts of poly-THF inimer and MMA monomer in CHCl3 were decreased versus time. It was compared the results obtained from t-BuBP-, BDBP-ZnCl2 initiating systems with t-BuBP-, BDBP-AgSbF6 initiating systems for THF monomer. Poly(THF-b-MMA) crosslinked block copolymers containing undecomposed peroxide groups
initiated the thermal polymerization of styrene, S, were used to obtain poly(THF-b-MMA-b-S) crosslinked multicomponent copolymers at 90°C. The crosslinked multi component copolymers were investigated sol-gel
analysis and swelling ratios in CHCl3. "Active" poly(THF-b-MMA) having peroxygen group were used in the free radical coupling reaction of poly butadien (Poly Bd). Poly(THF-b-MMA)-polybutadien crosslinked blend soluble graft copolymers were obtained.
Received: 31 July 2001/Revised version: 16 June 2002/ Accepted: 5 July 2002 相似文献
20.
Copolymers of sodium o‐methacryloylaminophenylarsonate (o‐MAPHA‐Na) 1 and p‐methacrylolylaminophenylarsonate (p‐MAPHA‐Na) 2 with sodium acrylate (AA‐Na) 3 , sodium methacrylate (AM‐Na) 4 and acrylamide (AAD) 5 were prepared by free radical polymerization in aqueous media at 70°C using potassium persulfate (K2S2O8) as the initiator. The total monomer concentration was carried out at 0.5M and the feed ratio ( M1 : M2 ) was varied from 10 : 90 to 90 : 10 mol%. The kinetic study was carried out by dilatometric method. The copolymer compositions were calculated by arsenic content in the copolymers. The As content (ppm) was determined by atomic absorption spectrometry (AAS). The reactivity ratios (r1, r2) were estimated by the Kelen‐Tüdös linearization method as well as error‐in‐variables method using the computer program RREVM®. In all cases, r1 < 1 and r2 > 1, indicating a tendency to form random copolymers. The values suggest that the copolymers contain a larger proportion of comonomer (i.e., AA‐Na, AM‐Na, or AAD). Weight‐average molar masses (M w) of copolymers were determined by multi‐angle light scattering. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献