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1.
Radical copolymerization of methyl methacrylate and methacrylamide was studied. For polymer films prepared from acetic acid solutions, the heat resistance and thermomechanical behavior were evaluated, and adhesion to silicate glass was determined.  相似文献   

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Copolymerization of acrylonitrile (AN) and ethyl methacrylate (EMA) using copper‐based atom transfer radical polymerization (ATRP) at ambient temperature (30 °C) using various initiators has been investigated with the aim of achieving control over molecular weight distribution. The effect of variation of concentration of the initiator, ligand, catalyst, and temperature on the molecular weight distribution and kinetics were investigated. No polymerization at ambient temperature was observed with N,N,N′,N′,N″‐pentamethyldiethylenetriamine (PMDETA) ligand. The rate of polymerization exhibited 0.86 order dependence with respect to 2‐bromopropionitrile (BPN) initiator. The first‐order kinetics was observed using BPN as initiator, while curvature in first‐order kinetic plot was obtained for ethyl 2‐bromoisobutyrate (EBiB) and methyl 2‐bromopropionate (MBP), indicating that termination was taking place. Successful polymerization was also achieved with catalyst concentrations of 25 and 10% relative to initiator without loss of control over polymerization. The optimum [bpy]0/[CuBr]0 molar ratio for the copolymerization of AN and EMA through ATRP was found to be 3/1. For three different in‐feed ratios, the variation of copolymer composition (FAN) with conversion indicated toward the synthesis of copolymers having slight changes in composition with conversion. The high chain‐end functionality of the synthesized AN‐EMA copolymers was verified by further chain extension with methyl acrylate and styrene. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1975–1984, 2006  相似文献   

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Investigations on free radical copolymerization of 1-vinyl naphthalene (1-VNph, monomerM 2) with styrene (St), methyl methacrylate (MMA) and acrylonitrile (AN) (monomersm 1) in bulk at 60°C with AIBN as initiator are presented. Relative reactivity ratios were calculated by the Kelen-Tüdös method yielding:r st=0.70 ±0.23 andr 1–VNph=2.02 ±0.40 for system St/1-VNph;r MMA=0.32 ±0.10 andr 1–VNph=0.57 ±0.07 for system MMA/1-VNph andr AN=0.11 ±0.03 andr 1–VNph=0.45 ±0.09 for system AN/1-VNph.Q, e values for 1-VNph according to Alfrey, Price scheme were calculated toQ 1–VNph=1.02,e 1VNph=–0.62.  相似文献   

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Copolymerizations of acrylonitrile and isoprene or butadiene were carried out in the presence of a new catalytic system containing Cr(O-tert-Bu)4 and AlEtCl2. It was found that the copolymer compositions have a highly alternating structure, even with varying feed ratios of monomer. The nuclear magnetic resonance spectra of the copolymers obtained with this catalytic system were observed and are discussed in terms of the alternation.  相似文献   

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It is possible to graft vinyl monomers, such as acrylonitrile, onto polystyrene via anionic processes but not by a radical process. Both homopolymerization of the added acrylonitrile and graft copolymerization in which acrylonitrile units are added to the para position on the benzene ring in styrene occur; the conversion of acrylonitrile into polymer depends upon the time and temperature of the reaction and on the concentration of the anionic initiator, butyllithium. A constant 15–20% of the acrylonitrile is converted to graft copolymer while the remainder is homopolymerized; graft copolymer may be separated from homopolymer by selective precipitation from either N,N′-dimethylformamide or aqueous potassium thiocyanate. Treatment of the mixed graft and homopolymer with aqueous sodium hydroxide converts the nitrile into an acid salt and one may conveniently separate homopolymer from graft copolymer in this way. Each polystyrene chain is grafted with acrylonitrile units. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1275–1282, 1997  相似文献   

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《European Polymer Journal》1987,23(6):489-492
Casein was grafted using acrylonitrile and n-butyl methacrylate. The mechanical properties of the grafted co-polymer films were studied using an Instron Universal Testing Machine. The morphological characteristics were studied by scanning electron microscopy. The tensile strength was found to increase and elongation at break to decrease with increasing monomer content. The compatibility of the graft co-polymer and homopolymer formed was found to be important in governing the morphological features of the films.  相似文献   

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Synthesis of two methacrylate monomers derivatives of carbonyl compounds: vanillin and acetone are presented. The obtained acetonyl methacrylate was used for copolymerization with methyl methacrylate. Copolymerizations were carried out in the presence of commercially available photoinitiator Irgacure 651. Thermal and mechanical properties of the copolymers with different concentration of acetonyl methacrylate were studied.  相似文献   

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The synthesis of styrene‐acrylonitrile copolymers by semicontinuous heterophase polymerization is reported here. The effect of feed composition at a fixed addition rate of monomer mixture on kinetics, particle size, polymer content, and molar masses, was studied. This process permits the synthesis of nanolatexes containing narrow size‐distribution particles with number‐average diameter (Dn) of about 18 nm, polymer content as high as 23 wt %, and copolymer‐to‐surfactant weight ratios between 23 and 25, depending on monomer feeding rate, which are larger than those reported for microemulsion copolymerization of several comonomers. Copolymers with homogeneous composition similar to the feeding monomers composition were obtained thorough the reaction, which is difficult to achieve by batch polymerization. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012  相似文献   

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Nitroxide-mediated polymerization (NMP) of isobornyl methacrylate (IBOMA) and tridecyl methacrylate (TDMA), derived from sustainable feedstocks, with a low fraction of acrylonitrile (AN) co-monomer were conducted with unimolecular initiator BlocBuilder-MA™ (BB) and the succinimidyl ester-functionalized form, NHS-BB. IBOMA and TDMA-rich compositions were both polymerized at 100 °C in a controlled manner (i.e., linear increase in number average molecular weight [Mn] with conversion up to ∼40% and low dispersity, Đ < 1.5). SG1-terminated poly(IBOMA-stat-AN) macroinitiator was then cleanly chain-extended with poly(TDMA-stat-AN) and the diblock copolymers exhibited two distinct glass transition temperatures (Tgs), indicative of microphase separation. IBOMA/TDMA/AN terpolymers with different IBOMA/TDMA molar ratios were also synthesized where terpolymers with higher IBOMA content had higher apparent rate constants and higher Tgs. Moreover, chain growth was linear up to conversions of ∼60% and all Đs were 1.51 to 1.64. Finally, 2-hydroxyethyl methacrylate (HEMA) was incorporated into the IBOMA/TDMA/AN system, resulting in statistical quadripolymers. The quadripolymer Tg decreased with increasing TDMA content and Mn ranged from 12 to 15.4 kg mol−1 and the Đ were 1.39 to 1.54, suggesting the successful incorporation of sustainably sourced monomers into quadripolymers with a broad range of tunable Tgs via NMP with additional functionalities from HEMA. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2422–2436  相似文献   

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Use was made of differential absorption in the near-infrared region to follow the rates of copolymerization of acrylonitrile (AN, M1) with ethylenesulfonic acid (ESA, M2) in aqueous zinc chloride solution. The concentrations of the monomers were followed separately and simultaneously. It was found experimentally that the ratios d log [M1]/dt and d log [M2]/dt were each constant. This was interpreted to mean that the product of the reactivity ratios of the two monomers (r1,r2) is unity and that the ratio of termination rate constants is equal to the propagation reactivity ratio. It was found that d log [M1]/d log [M2] = r1 = 4.52. This value is in fair agreement with polymer composition data obtained independently. In the Q—e system the equality r1r2 = 1 is equivalent to the monomers having equal e values. Thus, in the AN—ESA system, P1/P2 = k11/k21 = k12/k22 = k1T/k2T, where P1 is the resonance constant of polymer radicals ending in units of M1; and k11, k12, and k1T are the rate constants involving the reaction of this radical with M1, M2, and T (terminating agent), respectively. A gel effect was not observed even at M1 conversions as high as 88%.  相似文献   

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The study on homogeneous rare earth coordination catalysts, LnL3-Al(i-Bu)3-CCl4, for the copolymerization of styrene with acrylonitrile has been successfully carried out for the first time. Some features and kinetic behavior of copolymerization of styrene with acrylonitrile by Nd(P204)3-Al(i-Bu)3-CCl4 system are described. The catalyst sites appear to possess both coordinate anionic and free radical characteristics. The catalytic activity of various rare earth elements in Ln(P204)3 and ligands in NdL3 for the copolymerization have the following order, respectively: Yb > Er > Tb ~ Tm > Ho > Ce > Lu ~ Sm ~ La > Pr > Nd, and Nd(naph)3 > Nd(P204)3 ~ Nd(P507)3 > Nd(acac)3·3H2O. An alternating-rich copolymer of styrene-acrylonitrile with a high softening point (195–230°C) was obtained by the LnL3-Al(i-Bu)3-CCl4 systems in toluene at 80°C.  相似文献   

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