共查询到20条相似文献,搜索用时 16 毫秒
1.
Decheng Wan Lianjun Shi Junlian Huang 《Journal of polymer science. Part A, Polymer chemistry》1998,36(16):2927-2931
The spontaneous copolymerization of N-phenylmaleimide (NPMI) (M1) with ethyl α-phenylacrylate (EPA)(M2) were carried out in dioxane at 85°C. A high alternating tendency was observed. The monomer reactivity ratios were r1 = 0.07 ±0.01 and r2 = 0.09 ± 0.02. The maximum copolymerization rate and molecular weight occurs at 70–80 mol% (M1) in feed ratio. The spontaneous alternating copolymerization is considered to be carried out via a contact-type charge transfer complex (CTC) formed between the monomers. Thermogravimetric analyses (TGA) indicate the resulting copolymers have high thermal stability. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2927–2931, 1998 相似文献
2.
Anthony Winston George T. C. Li 《Journal of polymer science. Part A, Polymer chemistry》1967,5(6):1223-1231
The copolymerization of 4-cyclopentene-1,3-dione (M2) with p-chlorostyrene and vinylidene chloride is reported. The copolymers were prepared in sealed tubes under nitrogen with azobisisobutyronitrile initiator. Infrared absorption bands at 1580 cm.?1 revealed the presence of a highly enolic β-diketone and indicated that copolymerization had occurred. The copolymer compositions were determined from the chlorine analyses and the reactivity ratios were evaluated. The copolymerization with p-chlorostyrene (M1) was highly alternating and provided the reactivity ratios r1 = 0.32 ± 0.06, r2 = 0.02 ± 0.01. Copolymerization with vinylidene chloride (M1) afforded the reactivity ratios r1 = 2.4 ± 0.6, r2 = 0.15 ± 0.05. The Q and e values for the dione (Q = 0.13, e = 1.37), as evaluated from the results of the vinylidene chloride case, agree closely with the previously reported results of copolymerization with methyl methacrylate and acrylonitrile and confirm the general low reactivity of 4-cyclopentene-1,3-dione in nonalternating systems. 相似文献
3.
Peter C. Zhu Yuxia Liu Jinyan Lin Charles U. Pittman 《Journal of polymer science. Part A, Polymer chemistry》1996,34(11):2195-2203
Copolymers of the cyclic ketene acetals, 2-methylene-5,5-dimethyl-1,3-dioxane, 3 , (M1) with 2-methylene-1,3-dioxolane, 4 , (M2) or 2-methylene-1,3-dioxane, 5 , (M2), were synthesized by cationic copolymerization. An experimental method was designed to study the reactivity of these very reactive and extremely acid sensitive cyclic ketene acetal monomers. The reactivity ratios, calculated using a computer program based on a nonlinear minimization algorithm, were r1 = 6.36 and r2 = 1.25 for the copolymerization of 3 with 4 , and r1 = 1.56 and r2 = 1.42 for the copolymerization of 3 with 5. FTIR and 1H-NMR spectra when combined with the values of r1 and r2 showed that these copolymers were formed by a cationic 1,2-polymerization (ring-retained) route. Furthermore the tendency existed to form very short blocks of M1 or M2 within the copolymers. Cationic copolymerization of cyclic ketene acetals have the potential to be used for synthesis of novel polymers. © 1996 John Wiley & Sons, Inc. 相似文献
4.
Yoshihumi Bando Yuji Minoura 《Journal of polymer science. Part A, Polymer chemistry》1976,14(3):693-700
The homopolymerization and copolymerization of butadiene-1-carboxylic acid (Bu-1-Acid) (M1) were studied in tetrahydrofuran at 50°C with azobisisobutyronitrile as an initiator. The initial rate of polymerization was proportional to [AIBN]1/2 and [Bu-1-Acid]1. The overall activation energy for the polymerization was 22.87 kcal/mole. For copolymerization with styrene (M2) and acrylonitrile (M2), the monomer reactivity ratios r1, r2 were determined by the Fineman-Ross method, as follows; r1 = 5.55, r2 = 0.08 (M2 = styrene); r1 = 11.0, r2 = 0.03 (M2 = acrylonitrile). Alfrey-Price Q-e values calculated from these values were 6.0 and +0.11, respectively. The Bu-1-Acid unit in the copolymer as well as the homopolymer was found from infrared and NMR spectral analyses to be composed of a trans-1,4 bond. The hydrogen-transfer polymerization of Bu-1-Acid leading to polyester was attempted with triphenylphosphine as initiator, but did not occur. 相似文献
5.
The monomer reactivity ratios for the copolymerization of methacrylic acid (MA) and N-vinylpyrrolidone (NVP) in aqueous media at 30°C were determined as a function of pH (range 2-10), by use of both the modified differential (YBR) and integrated copolymerization equation to process the data at high conversions (< 70% by weight). The reactivity ratio r1 (for MA) ranges from 0.92 to 8.3 and that for NVP (r2) is very small except at pH 7 and 8. The ri values show two minima: 2.9 at pH 4 and 0.92 at pH 8, nearly corresponding to the pKa values of the monomer MA and the polymer, respectively. Addition of 1 M sodium chloride results in an increase of n values, and the values are still lower than those of the undissoeiated acid. The trend of rxwith pH is seen to follow that of the homopolymerization behavior of MA reported in the literature. The r1 and r2 are of the same order as those obtained in dimethylformamide in the literature. 相似文献
6.
Jan Lebduka Jaromîr nuprek Karel Kapar Vladimír ermk 《Journal of polymer science. Part A, Polymer chemistry》1986,24(4):777-791
The rate of solution copolymerization of styrene (M1) and 2-hydroxyethyl methacrylate (M2) was investigated by dilatometry. N,N-dimethyl formamide, toluene, isopropyl alcohol, and butyl alcohol were used as solvents. Polymerization was initiated by α,α′-azobisisobutyronitrile at 60°C. The initial copolymerization rate increased nonlinearly with increasing 2-hydroxyethyl methacrylate (HEMA)/styrene ratio. The copolymerization rate was promoted by solvents containing hydroxyl groups. Two different approaches were used for the prediction of copolymerization rates. The relationships proposed for the copolymerization rates calculation involve the effects of the total monomer concentration, mole fraction of HEMA, and of the solvent type. Different reactivity ratios were found in polar and nonpolar solvents: r1 = 0.53, r2 = 0.59 in N,N-dimethyl formamide, isopropyl alcohol and n-butyl alcohol; r1 = 0.50, r2 = 1.65 in toluene. The usability of these reactivity ratios was confirmed by batch experiments. 相似文献
7.
Kiyoshi Endo Takayuki Otsu 《Journal of polymer science. Part A, Polymer chemistry》1979,17(5):1441-1451
4-Phenyl-2-butene (4Ph2B) undergoes monomer-isomerization copolymerization with 4-methyl-2-pentene (4M2P) and 2-and 3-heptene (2H and 3H) with TiCl3–(C2H5)3Al catalyst at 80°C to produce copolymer consisting exclusively of 1-olefin units. For comparison the copolymerization of 4-phenyl-1-butene (4Ph1B) with 4-methyl-1-pentene (4M1P) and 1-heptene (1H) was carried out under similar conditions. The composition of the copolymers obtained from these copolymerizations was determined from the ratios of optical densities D1380 and D1600 of infrared (IR) spectra of their thin films. The apparent monomer reactivity ratios for the monomer-isomerization copolymerization of 4Ph2B with 4M2P, 2H, and 3H in which the concentration of olefin monomer in the feed was used as internal olefin and those for the copolymerization of 4Ph1B with 4M1P and 1H were determined as follows: 4Ph2B(M1)-4M2P(M2); r1 = 0.90, r2 = 0.20, 4Ph1B(M1)-4M1P (M2); r1 = 0.40, r2 = 0.70, 4Ph2B(M1)-2H(M2); r1, = 0.45, r2 = 1.85, 4Ph2B(M1)-3H(M2); r1 = 0.50, r2 = 1.20, 4Ph1B(M1)-1H(M2); r1 = 0.55, r2 = 0.75. The difference in monomer reactivity ratios seemed to originate from the rate of isomerization from 2- or 3-olefins to 1-oletins in these monomer-isomerization copolymerizations. 相似文献
8.
Naokazu Sakota Kiyoshi Kishiue Shyozo Shimada Yuji Minoura 《Journal of polymer science. Part A, Polymer chemistry》1974,12(8):1787-1797
Photosensitized copolymerization of optically active N-l-menthylmaleimide (NMMI) with styrene (Sty) and methyl methacrylate (MMA) was carried out in tetrahydrofuran (THF) at 30°C with benzoyl peroxide (BPO). The monomer reactivity ratios for the copolymerization of NMMI (M2) with Sty (M1) and MMA (M1) were r1 = 0.08 ± 0.10, r2 = 0.20 ± 0.05 and r1 = 2.85 ± 0.06, r2 = 0.07 ± 0.06, respectively. Copoly-MMA–NMMI and poly-NMMI showed positive circular dichroism(CD) curves of equal intensity and shape over the wavelength region from 230 to 270 nm; copoly-Sty–NMMI also showed a positive CD curve which was similar in shape but was different in intensity from that of poly-NMMI. The correlation between monomer unit ellipticity of the copolymers and their composition would suggest the alternating and stereoregular copolymerization of NMMI with Sty. 相似文献
9.
G. O. Schulz R. Milkovich 《Journal of polymer science. Part A, Polymer chemistry》1984,22(7):1633-1652
Copolymerization studies of methacrylate-terminated polystyrene macromonomers (M1) with several comonomers (M2) verified the modified kinetic scheme and permitted prediction of graft polymer compositions and structures. Instantaneous and cumulative copolymer compositions, average graft distributions, and grafts per molecule are predicted from FORTRAN IV or BASIC programs. The r2 relative reactivity ratios determined from styrene copolymerization (0.61) or from low conversion acrylic monomer in aqueous suspension (~0.4) had good agreement with literature values (about 0.6 and 0.4, respectively). Decreased macromonomer reactivity determined at high acrylic monomer conversions was attributed to phase separation phenomena. The Macromers also exhibited lower reactivity than predicted when copolymerized with acrylic monomers in DMSO/benzene solutions (r2 ~ 0.8). 相似文献
10.
Takayuki Otsu Kiyoshi Endo A. H. K. Yousufzai 《Journal of polymer science. Part A, Polymer chemistry》1979,17(5):1431-1440
2-Butene(2B) copolymerizes with 3-heptene(3H) and 4-methyl-2-pentene(4M2P) by a monomer-isomerization copolymerization mechanism in the presence of TiCl3–(C2H5)3Al catalyst at 80°C to yield the copolymers of 1-olefin units. By comparison, the copolymerization of 1-butene(1B) with 4-methyl-1-pentene(4M1P) was also carried out under similar conditions. The composition of the copolymers obtained from these copolymerizations was determined from the ratios of optical densities D723/D1380 and D1170/D1380 in their infrared (IR) spectra. The apparent monomer reactivity ratios for the monomer-isomerization copolymerization of 2B with 3H and 4M2P, in which the concentration of olefin monomer in the feed was used as 2-olefin, were determined as follows: cis-2B(M1)/3H(M2); r1 = 4.00, r2 = 0.20: trans-2B(M1)/3H; r1 = 3.50, r2 = 0.20; 4M2P(M1)-trans-2B(M2): r1 = 0.05, r2 = 9.0. These results indicate that the isomerization of 2-olefins to 1-olefins was important to monomer-isomerization copolymerization. 相似文献
11.
Katsutoshi Nagai Keisuke Asada Keiji Chiba Noriyuki Kuramoto 《Journal of polymer science. Part A, Polymer chemistry》1989,27(11):3779-3787
α-Trimethylsilyloxystyrene (TMSST), the silyl enol ether of acetophenone, was not homopolymerized either by a radical or a cationic initiator. Radical copolymerization of TMSST with styrene (ST) and acrylonitrile (AN) in bulk and the terpolymerization of TMSST, ST, and maleic anhydride (MA) in dioxane were studied at 60°C and the polymerization parameters of TMSST were estimated. The rate of copolymerization decreased with increased amounts of TMSST for both systems. Monomer reactivity ratios were found as follows: r1 = 1.48 and r2 = 0 for the ST (M1)–TMSST (M2) system and r1 = 0.050 and r2 = 0 for the AN (M1)–TMSST (M2) system. The terpolymerization of ST (M1), TMSST (M2), and MA (M3) gave a terpolymer containing ca. 50 mol % of MA units with a varying ratio of TMSST to ST units and the ratio of rate constants of propagation, k32/k31, was found to be 0.39. Q and e values of TMSST were determined using the values shown above to be 0.88 and ?1.13, respectively. Attempted desilylation by an acid catalyst for the copolymer of TMSST with ST afforded polystyrene partially substituted with hydroxyl groups at the α-position. 相似文献
12.
Youliang Zhao Pengsheng Liu Hongwei Liu Jing Jiang Chuanfu Chen Fu Xi 《Macromolecular rapid communications》2001,22(8):633-637
By using sodium dodecyl sulfate (SDS) and pentanol (PTL) as emulsifiers, the oil‐in‐water microemulsion containing N‐butyl maleimide (NBMI, M1) and styrene (St, M2) was prepared. The microemulsion copolymerization using potassium persulfate (KPS) as an initiator was investigated. On the basis of kinetic model proposed by SHAN Guo‐Rong, the reactivity ratios of free monomers and the charge‐transfer complex (CTC) in the copolymerization were found to be r12 = 0.0420, r21 = 0.0644, r1C = 0.00576 and r2C = 0.00785, respectively. A kinetic treatment based on this model was used to quantitatively estimate the contribution of CTC to the total copolymerization rate in the NBMI/St copolymerization. It was about 17.0–20.0% for a wide range of monomer feed ratios. 相似文献
13.
Emulsion polymerization of vinyl benzoate and its copolymerization with vinyl acetate or styrene are described. The effect of the potassium persulfate initiator, and the sodium lauryl sulfate emulsifier concentration on the rate of vinyl benzote homopolymerization and the molecular weight of the polymers was determined. In copolymerization with vinyl benzoate, both comonomers, vinyl acetate and styrene, decrease the initial polymerization rate. With increasing amounts of styrene in the comonomer mixture the polymerization rate increases but with vinyl acetate an opposite effect is observed. Reactivity ratios of copolymerizations were determined. For the vinyl benzoate [M1]-styrene [M2] comonomer system a r1 = 0.03 and a r2 = 29.58 and for vinyl benzoate [M1]-vinyl acetate [M2], a r1 = 1.93 and a r2 = 0.20 was obtained. From the vinyl benzoate-styrene reactivity ratios the Qe parameters were calculated. 相似文献
14.
Koji Ohta Yoshio Okamoto Koichi Hatada Heimei Yuki 《Journal of polymer science. Part A, Polymer chemistry》1979,17(9):2917-2928
The monomer reactivity ratios were determined in the anionic copolymerization of (S)- or (RS)-α-methylbenzyl methacrylate (MBMA) and trityl methacrylate (TrMA) with butyllithium at ?78°C, and the stereoregularity of the yielded copolymer was investigated. In the copolymerization of (S)-MBMA (M1) and TrMA (M2) in toluene the monomer reactivity ratios were r1 = 8.55 and r2 = 0.005. On the other hand, those in the copolymerization of (RS)-MBMA with TrMA were r1 = 4.30 and r2 = 0.03. The copolymer of (S)-MBMA and TrMA prepared in toluene was a mixture of two types of copolymer: one consisted mainly of the (S)-MBMA unit and was highly isotactic and the other contained both monomers copiously. The same monomer reactivity ratios, r1 = 0.39 and r2 = 0.33, were obtained in the copolymerizations of the (S)-MBMA–TrMA and (RS)-MBMA–TrMA systems in tetrahydrofuran (THF). The microstructures of poly[(S)-MBMA-co-TrMA] and poly-[(RS)-MBMA-co-TrMA] produced in THF were similar where the isotacticity increased with an increase in the content of the TrMA unit. 相似文献
15.
Turner Alfrey Charles R. Pfeifer 《Journal of polymer science. Part A, Polymer chemistry》1966,4(10):2447-2460
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
16.
Copolymerization of styrene (St) and isoprene (IP) with nickel(II) acetylacetonate [Ni(acac)2] and methylalumoxane (MAO) catalyst was investigated. It was found that the Ni(acac)2-MAO catalyst is effective for the copolymerization of St and IP. From the copolymerization of St (M1) and IP (M2) and IP (M2) with the Ni(acac)2-methylalumoxane catalyst, the monomer-reactivity ratios were determined to be r1 = 1,18 and r2 = 0,88, i.e., ideal copolymerization was found to proceed to give perfectly random copolymers without formation of any homopolymer. The microstructure of IP units in the copolymers exhibits high cis-1,4 contents. 相似文献
17.
Shojiro Kaita Takako Otaki Eiichi Kobayashi Sadahito Aoshima Junji Furukawa 《Journal of polymer science. Part A, Polymer chemistry》1997,35(13):2591-2597
The polymerization of polar monomers such as methyl methacrylate (MMA), methyl acrylate (MA), methacrylonitrile (MAN), and acrylonitrile (AN) was carried out with gadolinium-based Ziegler–Natta catalysts [Gd(OCOCCl3)3-(i-Bu)3Al-Et2AlCl] in hexane at 50°C under N2 to elucidate the effect of the monomer's HOMO(highest occupied moleculor orbital) and LUMO (lowest unoccupied molecular orbital) levels on the polymerizability. In the case of homopolymerization, all monomers were found to polymerize and the order of relative polymerizability was as follows: MM > MA > MAN > AN. On the other hand, the result of copolymerization of St with MMA shows that the values of the monomer reactivity ratios are r1 = 0.06 and r2 = 1.98 for St(M1)/MMA(M2). The monomer reactivity ratios of styrene (St), p-methoxystyrene (PMOS), p-methylstyrene (PMS), and p-chlorostyrene (PCS) evaluated as r1 = 0.55 and r2 = 1.07 for St(M1)/PMOS(M2), r1 = 0.38 and r2 = 0.51 for St(M1)/PMS(M2), and r1 = 0.72 and r2 = 1.25 for St(M1)/PCS(M2) were compared with those for St(M1)/MMA(M2). The copolymerization behavior is apparently different from the titanium-based Ziegler—Natta catalyst, regarding a larger monomer reactivity ratio of PCS. The lower LUMO level of PCS and MMA may enhance a back-donation process from the metal catalyst, therefore resulting in high polymerizability. These results are discussed on the basis of the energy level of the gadolinium catalyst and the HOMO and LUMO levels of the monomers. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2591–2597, 1997 相似文献
18.
Tetsuji Ohata Etsuro Fukumori Akira Matsumoto Masayoshi Oiwa 《Journal of polymer science. Part A, Polymer chemistry》1980,18(3):1011-1019
The radical copolymerization of diallyl tartrate (DATa) (M1) with diallyl succinate (DASu), diallyl phthalate (DAP), allyl benzoate (ABz), vinyl acetate (VAc), or styrene (St) was investigated in order to disclose in more detail the characteristic hydroxyl group's effect observed in the homopolymerization of DATa. In the copolymerization with DASu or DAP as a typical diallyldicarboxylate, the dependence of the rate of copolymerization on monomer composition was different for different copolymerization systems and unusual values larger than unity for the product of monomer reactivity ratios, r1r2, were obtained. In the copolymerization with ABz or VAc (M2), the r1 and r2 values were estimated to be 1.50 and 0.64 for the DATa/ABz system and 0.76 and 2.34 for the DATa/VAc system, respectively; the product r1r2 for the latter copolymerization system was found again to be larger than unity. In the copolymerization with St, the largest effect due to DATa monomer of high polarity was observed. Solvent effects were tentatively examined to improve the copolymerizability of DATa. These results are discussed in terms of hydrogen-bonding ability of DATa. 相似文献
19.
Tsuneyuki Sato Takashi Kitajima Makiko Seno Yukako Hayashi 《Journal of polymer science. Part A, Polymer chemistry》1998,36(9):1449-1455
The copolymerization of p-tert-butoxystyrene (TBOSt) (M1) and di-n-butyl maleate (DBM) (M2) with dimethyl 2,2′-azobisisobutyrate (MAIB) in benzene at 60°C was studied kinetically and by means of ESR spectroscopy. The monomer reactivity ratios were determined to be r1 = 2.3 and r2 = 0 by a curve-fitting method. The copolymerization system was found to involve ESR-observable propagating polymer radicals under practical copolymerization conditions. The apparent rate constants of propagation (kp) and termination (kt) at different feed compositions were determined by ESR. From the relationship of kp and f1 (f1 = [M1]/([M1] + [M2])) based on a penultimate model, the rate constants of five propagations of copolymerization were evaluated as follows; k111 = 140 L/mol s, k211 = 3.5 L/mol s, k112 = 61 L/mol s, k212 = 1.5 L/mol s, and k121 = 69 L/mol s. Thus, a pronounced penultimate effect was predicted in the copolymerization. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1449–1455, 1998 相似文献
20.
The copolymerization reactivity ratios for styrene/m- and styrene/p-divinylbenzene have been determined at high conversions (<35%) using the integrated form of the copolymerization equation. Values of r1 (s) = 1.11, r2 (m) = 1.00; and r1 (s) = 0.20, r2 (p) = 1.00 were obtained. These values indicate the same relative behavior but are quantitatively different from the differential data. The data confirm that the para isomer is incorporated more rapidly into the growing polymer chain than is the meta isomer. 相似文献