bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface graft polymerization of acrylamide onto poly(ethylene terephthalate) film by UV irradiation
Authors: Uchida Emiko , Uyama Yoshikimi , Ikada Yoshito
Published: April 2003

To improve the low water wettability of poly(ethylene terephthalate) (PET), graft polymerization of acrylamide (AAm) by UV irradiation was performed onto the surface of a PET film with the simultaneous irradiation method without using a photo sensitizer. The PET film immersed in a 10 wt % deaerated aqueous solution of AAm was found to become highly hydrophilic upon UV irradiation. Optical microscopy on cross sections of grafted films showed that localization of the graft polymerization was restricted to a thin surface region of the film. Both the low concentration of polymer radicals formed by UV irradiation and the monomer penetration limited to the film surface would be responsible for localization of the grafted layer to the film surface region. Pretreatment of the PET film with benzyl alcohol was effective for enhancement of the graft polymerization. Retention of high hydrophilicity of the surface even after rigorous extraction of homopolymer and a comparative study of polymerization without UV irradiation strongly suggested that UV irradiation of the PET film under immersion in the deaerated AAm aqueous solution would lead to formation of the true graft copolymer.
IR studies of polyimides. I. Effects of chemical and physical changes during cure
Authors: Pryde C. A.
Published: April 2003

A detailed study has been made of the thermal cure of two polyimides using infrared analysis. It is shown that two of the IR bands commonly used to determine the amount of imidization are affected by both interference from other species and by polymer morphology. These bands, located near 1780 cm−1 and 730 cm−1, overlap bands attributed to anhydride, which is formed when the polymer is heated. A correction for this effect is described. However, the measured absorbances of these bands are also subject to a dichroic effect. Any anisotropy in the samples can therefore affect the results. A third band, that located near 1370 cm−1, does not overlap anhydride peaks and did not, using the approach described here, display any effect due to dichroism. Thus it appears to offer a reliable way of following imidization by IR.
Studies of the polymerization of diallyl compounds. XLI. Discussion of substantially identical gel points among three isomeric diallyl phthalates
Authors: Matsumoto Akira , Ogasawara Yuji , Nishikawa Sadahiko , Aso Takayuki , Oiwa Masayoshi
Published: April 2003

In the bulk polymerization of three isomeric diallyl phthalates, diallyl phthalate (DAP), diallyl isophthalate, and diallyl terephthalate (DAT), no difference in the actual gel point was substantially observed. This interesting gelation behavior is discussed in terms of the correlation between gelation and the difference in cyclization modes, and the difference in reactivity between the uncyclized and cyclized radicals for crosslinking; the nonconsecutive addition in DAT polymerization led to a delayed gelation and the cyclized radical in DAP polymerization showed an enhanced reactivity for crosslinking.
Preparation of poly(ethylene terephthalate) in the presence of a telechelic perfluoropolyether
Authors: Pilati F. , Bonora V. , Manaresi P. , Munari A. , Toselli M. , Re A. , De Giorgi M.
Published: April 2003

Polyethylene terephthalate (PETP) has been prepared from dimethyl terephthalate and ethylene glycol in the presence of various amounts of a telechelic fluorinated macromer with methyl ester end‐groups using Ti(OBu)4 as the catalyst. The final products are heterophasic with a perfluoropolyether phase embedded in a PETP matrix. The effects of the fluorinated polymer on the reaction rates in the first and second stages of the reaction and on some properties (Tg, Tm, and contact angle) are discussed.
Synthesis and characterization of liquid crystalline polymethacrylates, polyacrylates, and polysiloxanes containing 4‐methoxy‐4′‐hydroxy‐α‐methylstilbene‐based mesogenic groups
Authors: Percec Virgil , Tomazos Dimitris
Published: April 2003

The synthesis and characterization of polymethacrylates and polyacrylates containing 4‐methoxy‐4′‐hydroxy‐α‐methylstilbene side groups attached either directly or through flexible spacers containing eleven, eight, six, three, and respectively two methylenic units, and of the polysiloxanes containing the same mesogenic group connected through flexible spacers containing eleven, eight, six, and respectively three methylenic units are described. All polymers exhibit thermotropic liquid crystallinity. The nature of the mesophase is determined by the spacer length. However, the nature of the polymer backbone determines the thermal stability of the mesophase. That is, for the same spacer length and similar polymer molecular weight, the most flexible polymer backbone leads to the highest isotropization temperature.
A study of sulfur‐free thiuram vulcanization using differential scanning calorimeter
Authors: Duchác̆ek Vratislav , Bhattacharyya Timir Baran , Kuta Antonin
Published: April 2003

A number of curative mixtures without rubber and with natural rubber or polybutadiene based on binary and tertiary combinations of zinc oxide, tetramethylthiuram disulfide, and 2‐mercaptobenzothiazole were treated in a differential scanning calorimeter. From the shapes of exothermal curves a zinc‐accelerator complex formation has been examined. Although the experimental results can give no direct evidence for the structure of the complexes, they do contribute to an elucidation of the complex formation in the vulcanization process.
Polyimides containing carbonyl and ether connecting groups. II
Authors: Hergenrother P. M. , Havens S. J.
Published: April 2003

In a continuation of our effort on polyimides containing carbonyl and ether connecting groups between aromatic rings, several new polyimides were prepared and characterized. A few of these polymers were semi‐crystalline. Glass transition temperatures ranged from 164 to 258°C and crystalline melt temperatures were observed between 350 and 424°C. The semi‐crystalline polyimide from the reaction of 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 1,3‐bis(4‐aminophenoxy‐4′‐benzoyl)benzene provided transparent orange films with excellent tensile properties, exceptional resistance to solvents and strong base, and high thermooxidative stability. In addition, this polyimide provided excellent adhesive strength for joining titanium (6A1–4V) to titanium.
Kinetic modelling and optimization of the trifluoropropylmethylsiloxane polymerization
Authors: Veith C. A. , Cohen R. E.
Published: April 2003

Use of promoter dimethylsulfoxide (DMSO) in conjunction with initiator normal butyllithium has resulted in rapid and controllable ring‐opening polymerization of 1,3,5‐tris‐(3′,3′,3′‐trifluoro‐propyl)1,3,5‐trimethylcyclotrisiloxane at 40°C; monomer consumption rate can be varied by at least four orders of magnitude depending on the ratio of promoter‐to‐initiator concentrations. Compared to the sodium counterion also studied here, the lithium initiator slows the backbiting alkyl‐reactions which cause degradation of polymer to cyclics containing four or more fluoroal‐kylsiloxy units. This previously uninvestigated polymerization methodology offers greater opportunity for capturing high, nonequilibrium polymer yield of this fluoroalkylsiloxane through appropriately timed termination of the reaction. To facilitate this optimization, a kinetic model of the polymerization was developed by solving the isothermal, constant density rate expressions for a two‐step, series mechanism. The solution to the coupled system of nonhomogeneous ordinary differential equations is obtained by matrix variation of parameters. The rate constants were determined by appropriate kinetic analysis of the experimental data obtained for polymer and cyclics concentrations as a function of time under various conditions. This results in a quantitative model capable of predicting optimum polymerization time to maximize the yield of poly(3,3,3‐trifluoropropylmethylsiloxane) at ca. 85–90%.
On the kinetics and mechanism of copolymerization of vinyl acetate and itaconic monomers
Authors: Kotzeva L. , Mateva R.
Published: April 2003

The introduction of anionic hydrophylic groups in the pendant chain of polyvinyl alcohol improves its surface and adhesive properties. For the purpose of synthesizing raw materials for preparation of modified polyvinyl alcohol with enhanced performance characteristics, the copolymerization of vinyl acetate with itaconic acid and diethyl itaconate at concentrations up to 9 mol % in methanol solution using azo‐bis‐isobutyronitrile and tert‐butylcyclohexylperoxydicarbonate as initiators has been studied. The experiments were performed using two different methods of addition of the itaconic monomer—single, at the beginning of the process, and continuous. It was established that the process rate decreases as the quantity of the second comonomer increases. The reaction order in terms of itaconic acid ( −2, 95) and reactivity ratios for both pairs vinyl acetate and itacinic acid (r1 = 0.053 and r2 = 31) and vinyl acetate and diethyl itaconate (r1 = 0.125 and r2 = 18) were determined. The products obtained were characterized by IR and NMR. It was confirmed that for the case of single addition at the beginning of the process a two‐phase system is formed while the continuous addition resulted in random group distribution.
Metallocene–methylaluminoxane catalysts for olefin polymerizations. III. Reduction of η5‐cyclopentadienyl trichlorides of titanium and zirconium
Authors: Bueschges Ulrich , Chien James C. W.
Published: April 2003

The reactions occurring between the components of metallocene and methylaluminoxane (MAO) catalyst leading to the reduction of the former were studied by electron paramagnetic resonance (EPR). At low Al/Zr ratios, CpZrCl3 (Cp = η5‐cyclopentadienyl) was reduced to simple trivalent Zr species (g = 1.998, a(91Zr) = 12.3 G) without other superhyperfine splittings. At higher Al/Zr ratios the reactions proceed further to form two CpZr(III) hydrides (g = 1.991, a(H) = 5.5 G; and g = 2.00, a(H) = 3 G). Two CpTi(III) hydrides were also produced by the reaction of MAO with CpTiCl3 (g = 1.989, a(H) = 7.4 G, a(Ti) = 8 G; and, g = 1.995, a(H) = 4.5 G, a(Ti) = 8 G). In the case of Cp*TiCl3 (Cp* = η5‐pentamethyl cyclopentadienyl) initially a multitude of paramagnetic species were formed. After long reaction time the final products show EPR features consistent with two η3: η4‐(1,2,3‐trimethyl‐4,5‐dimethylene cyclopentadienyl)hydrido Ti(III) species: the abundant one with g = 1.999, (H, sextet) = 9.5 G, a(Ti) = 9.5 G, and a weaker one of g = 1.975, a(H) = 4.8 G. All the five protons of these species and as well as those in the Cp hydrido complexes of Ti and Zr undergo facile HD exchanges with D2. MAO is important in the formation of these hydrides because they are not formed by trimethyl aluminum reduction. The presence of tetrahydrofuran suppresses the hydride formation. The possible structures for the hydrido species and reactions producing them are discussed.
Copolymerization of methyl acrylate and vinyl acetate catalyzed by ethylaluminium chlorides
Authors: Florjańczyk Zbigniew , Skórkiewicz Bogdan
Published: April 2003

The copolymerization of vinyl acetate with methyl acrylate in the presence of Et2AlCl, Et1.5AlCl1.5, and Et2AlCl‐benzoyl peroxide systems has been investigated. The influence of monomer ratios and organoaluminium compound concentration on the copolymer yield and composition have been determined and discussed. The monomer sequences distribution has been studied by means of 13C‐NMR. It was found that organoaluminium compounds in the studied systems catalyze not only the alternating copolymerization, but also the homopropagation of both monomers. An alternating copolymer was obtained in reactions carried out at −78°C, when a large excess of vinyl acetate was used in the monomer feed.
Radiolysis of poly(acetaldehyde‐co‐chloral): A positive E‐beam resist
Authors: Zhao X. , Xu B. , Chien James C. W. , Khanna D. N.
Published: April 2003

Acetaldehyde and chloral were copolymerized using triethyl aluminum catalyst. The copolymer (ACC) obtained with equimolar monomer feed is not alternating in structure as it was once thought to be; it is comprised of two fractions differing in MW and composition. ACC has good thermal stability which is further improved by endcapping. Radiolysis in vacuo caused depolymerization with a G(M) value (number of monomers produced per 100 eV) of about 4000 to 80% completion. The G(S) value for chain scission is 1.9. These processes are effectively inhibited by benzoquinone. Oxygen markedly increases G(M) to ca. 18,000 and > 97% completion. Addition of tetrabutyl ammonium salt or tetramethyl urea has no effect on the depolymerization, whereas the addition of di‐t‐butyl‐p‐cresol causes an induction period after which normal unzipping ensues. Even UV photolysis of ACC in the presence of oxygen produces monomer with a quantum yield of 1.7, but very little photolysis occurs in the absence of oxygen. Gamma radiolysis sensitized by (C6H5)2IPF6 has G(M) value of 32,700. These results are very similar to the radiolysis and photolysis of the homopolymer of monochloroacetaldehyde and reinforce the mechanisms proposed for them. The E‐beam sensitivity of ACC is about 3 × 10−6 C cm−2.
Surface modification of polymers. II. Grafting with glycidyl acrylates and the reactions of the grafted surfaces with amines
Authors: Allmér K. , Hult A. , Rånby B.
Published: April 2003

The surface of low density polyethylene has been grafted with glycidyl acrylate and glycidyl methacrylate by photoinitiation. ESCA measurements on the grafted surface showed a 72% coverage for glycidyl acrylate and 52% for glycidyl methacrylate after 10 min of grafting with UV irradiation. ATR–IR showed a 10 times more extensive grafting for glycidyl acrylate than for glycidyl methacrylate after 10 min of grafting, indicating reaction to deeper layers. Acetone and ethanol were used as solvents: acetone yielded slightly more grafting at the surface. The grafted surfaces were reacted with 2M solutions of aniline and propylamine in ethanol. After 4 h reaction at 60°C, with aniline 52% of the epoxy groups while for propylamine 96% of the groups were consumed, as measured with ATR–IR.
Synthesis of poly(amino acid)s on molecular assemblies formed by functional active esters of amino acids
Authors: Hanabusa K. , Tsutsumi H. , Kurose A. , Shirai H. , Hayakawa T. , Hojo N.
Published: April 2003

The new active β‐alanine and glycine esters (6 and 7) of N‐hydroxy‐2,3‐dihexadecylsuccinimide were prepared and their polycondensation was studied. The aggregation behavior of these esters was examined by an electron microscopy and an osmotic method. They formed multilamella in water and reversed micelle in nonpolar solvents. These solvents were found to be suitable for the polycondensation, which gave the corresponding poly(amino acid)s. The results of polycondensation can be explained by assuming that the aggregations, that is, multilamella in water and reversed micelle in nonpolar solvents, are playing an important role in the polycondensation.
Grafting of a bicycloorthoester onto polymers bearing sulfonium salt structures
Authors: Uno Hitomi , Takata Toshikazu , Endo Takeshi
Published: April 2003

Graft copolymerization of a bicycloorthoester (BOE) with polymer‐supported sulfonium salts was studied. Several polymer‐supported sulfonium salts were prepared by the homopolymerizations of p‐vinylbenzyl tetramethylenesulfonium hexafluoroantimonate (2) and 4‐(p‐vinylphenyl)butyl tetramethylenesulfonium hexafluoroantimonate (3), and by the copolymerizations of 2 with some vinyl monomers (n‐butyl vinyl ether, styrene, acrylonitrile, and p‐styrenesulfonic acid potassium salt). These sulfonium salts could initiate the polymerization of BOE to give grafted polymers. Temperature dependences of the catalytic activity of them were not so dramatic as that of benzyl tetramethylenesulfonium hexafluoroantimonate (1), but the activities of them were higher than that of 1 at temperatures lower than 80°C. The conversion of BOE in the polymerizations with these polymer initiators was ca. 30–70% at 120°C for 7 h. An effect of the comonomer structure on the catalytic activity was observed and styrene was the best comonomer for 2 in terms of the reactivity of the copolymer. The spacer‐modified sulfonium salt (homopolymer of 3) was slightly lower than polymer‐supported benzyl type sulfonium salt (homopolymer of 2) in the catalytic activity.
Polymerization of methyl methacrylate with cupric laurate–benzoin system as initiator
Authors: Pal Prabir Kumar , Nandi Dipa , Chaudhuri Ajit Kumar
Published: April 2003

The polymerization of methyl methacrylate initiated by cupric laurate in combination with benzoin has been investigated in carbon tetrachloride medium at 60°C. The rate of polymerization was found to be proportional to the square root of both cupric ion and benzoin concentrations, and to the 1.5th power of the monomer concentration. Spectral studies indicated that there is a complex formation between cupric ion and the monomer methyl methacrylate. A reaction scheme, based on initial formation of the complex and its subsequent reaction with benzoin to produce the free radicals responsible for initiation has been postulated to explain the observed results.
Preparation and complexation of an A–B–A type triblock copolymer consisting of helical poly(L‐proline) and random‐coil poly(ethylene oxide)
Authors: Jeon Seung Ho , Park Soon Moon , Ree Taikyue
Published: April 2003

By using L‐proline N‐carboxyanhydride (LPNCA) and amino‐group terminated poly(ethylene oxide) (ATPEO), an A–B–A–type [A = poly(L‐proline) (PLP), B = poly(ethylene oxide) (PEO)] triblock copolymer (POP) was prepared which is water‐soluble. In the POP, A = PLP is helical, and B = PEO is random coil. From the observations of the NMR spectra, specific optical rotation, and x‐ray diffraction of the POP, it was found that the PLP component of the POP exists nearly as Form II PLP with trans‐configuration, and interferes the crystal growth of PEO component, in solid state. With the addition of PMAA into an aqueous POP solution, dramatic decreases of reduced viscosity and pH are observed until the unit‐mole‐concentration‐ratio (UMCR) [PMAA]/[POP] reaches its value of unity, while a distinct increase in turbidity appears. This shows a 1 : 1 interpolymer complex formation between PMAA and POP in aqueous medium through hydrogen bonding. The curves of viscosity, pH, and turbidity versus UMCR [PMAA]/[POP] show breaks at [PMAA]/[POP] = 0.3, suggesting the selective complexation of PLP component (ca. 30 unit‐mol %) of POP with PMAA. The x‐ray diffraction curve of the complex POP/PMAA shows entirely no diffraction patterns, indicating that the ordered POP structure (mainly due to that of PLP component) is completely destroyed owing to the complexation between POP and PMAA.
γ‐irradiation of polypropylene in vacuum and in air
Authors: Imai Masahiko , Xu Lu Gong , Ametani Kazuo , Tutiya Mituaki
Published: April 2003

Polypropylene films were irradiated with 60Co γ‐rays in vacuum or in air and stored in air. Just after irradiation, the concentration of carbonyl group of the sample irradiated in air only increased with dose. The concentrations of both samples increased with storage time. The more the absorbed doses, the higher the increasing rates. The increasing rate of the concentration of carbonyl group during irradiation in air was higher than those during storage in air. Just after irradiation, the tensile strengths and the elongations of the both samples somewhat increased with dose at the doses less than 5 Mrad, but decreased at doses more than 13 Mrad. The tensile strength and the elongation of the sample irradiated in air decreased with storage time. Those of the sample irradiated in vacuum also decreased with storage time but the decreasing rates were much smaller than those in the sample irradiated in air. The gel fractions of the samples irradiated in vacuum and annealed in vacuum were somewhat higher than those irradiated in vacuum and not annealed. To elucidate high oxidation rate in the sample irradiated in air during and after irradiation, reaction mechanisms were discussed. To clarify the difference of mechanical properties between the samples irradiated in vacuum and in air, the effect of crosslink was considered, together with the oxidation.
Radical ring‐opening polymerization behavior of vinylcyclopropanes derived from dienes and chloroform
Authors: Endo Takeshi , Suga Katsufumi
Published: April 2003

1,1‐Dichloro‐2‐vinylcyclopropane (Ia), 1,1‐dichloro‐2‐methyl‐2‐vinylcyclopropane (Ib), 1,1,2‐trichloro‐2‐vinylcyclopropane (Ic) were prepared from the corresponding dienes and chloroform in the presence of a phase transfer catalyst (PTC), R4N+Cl−. Monomers Ia–Ic underwent a clean 1,5‐type radical ring‐opening process to afford the corresponding polymers in good yield. Further, the relative rate of polymerization and reaction of (I) with thiophenol were studied.
Electrochemical synthesis of conducting polymers from oligomers containing thiophene and furan rings
Authors: Galal Ahmed , Lewis Edmund T. , Ataman O. Yavuz , Zimmer Hans , Mark Harry B.
Published: April 2003

Oligomers containing 2,5‐thienylene and 2,5‐furanylene units were synthesized by NiCl2 (dppp) (dppp = Ph2PCH2CH2CH2PPh2) coupling of Grignard compounds with the appropriate bromothiophene or bromofuran; UV and electrochemical data are given and discussed in terms of number and kind of heterolene units in the oligomeric species.
Surface and solution properties of polysiloxane–poly(methyl methacrylate) graft copolymer
Authors: Chujo Yoshiki , Samukawa Hiroshi , Yamashita Yuya
Published: April 2003

A polysiloxane–poly(methyl methacrylate) (PMMA) graft copolymer was prepared by hydrosilylation reaction between a SiH containing polysiloxane and an allyl‐terminated PMMA. The obtained graft copolymer was blended with PMMA homopolymer. The addition of only 0.01 wt % of graft copolymer was sufficient to make PMMA surfaces hydrophobic. In acetone–cyclohexane mixed solvent, the graft copolymer formed a polymeric micelle by the aggregation of PMMA branches.
Preparation of monodisperse hydrophilic polyamide by anionic polymerization of bicyclic oxalactam
Authors: Hashimoto Kazuhiko , Sumitomo Hiroshi , Washio Atsuko
Published: April 2003

The preparation of a monodisperse hydrophilic polyamide was achieved in the anionic polymerization of a bicyclic oxalactam, 8‐oxa‐6‐azabicyclo[3.2.1]octan‐7‐one (abbreviated BOL) with the use of N‐benzoyl BOL and potassium pyrrolidonate (2 and 0.5 mol % to BOL, respectively) in dimethyl sulfoxide at 25°C. The number‐average molecular weight of the polyamide increased in direct proportion to the monomer conversion, and was consistent with the value calculated from the amounts of the consumed monomer and activator. The molecular weight distribution (MWD) of the polyamide obtained until the middle stage of polymerization (polymerization time, < 10 min; monomer conversion, < 60%) was found to be narrow (Mw/Mn = 1.1). The MWD was gradually broadened in the later stage of the polymerization, which may result from the redistribution of molecular weight of the resulting polyamide not only by the polymerization–depolymerization equilibrium, but also by transamidation between polymer chains.
Hydrolysis of alkyl cyanoacrylate and ethoxycarbonylpropenoylphosphonate polymers
Authors: Cooper A. W. , Harris P. J. , Kumar G. K. , Tebby J. C.
Published: April 2003

The polymers of ethyl α‐cyanopropenoate (widely known as cyanoacrylate) and dimethyl (α‐ethoxycarbonyl)propenoylphosphonate have been hydrolyzed and their rates of degradation to formaldehyde have been compared. The phosphate polymer produced much less formaldehyde than the cyanopropenoate polymer as required for an improved surgical adhesive. In a comparative study, the rate of aqueous hydrolysis of a high molecular weight cyanoacrylate polymer differed from a previous report. The nature and the hydrolytic properties of the end groups in the two types of polymer are discussed.
Synthesis of aromatic dicarboxyl‐terminated poly(methyl methacrylate) macromonomers
Authors: Chujo Yoshiki , Kobayashi Hisaaki , Yamashita Yuya
Published: April 2003

Hydroxyl‐ or amino‐terminated prepolymers were prepared by radical polymerization of methyl methacrylate in the presence of 2‐mercaptoethanol or 2‐aminoethanethiol hydrochloride, respectively, as a chain transfer agent. The resulting prepolymers were subjected to react with trimellitic anhydride to form aromatic dicarboxyl‐terminated poly(methyl methacrylate)s. These condensation‐type macromonomers and terephthalic acid were condensed with bisphenol‐A to produce polyester–poly(methyl methacrylate) graft copolymers.
Nomenclature of polymers (based on structure)
Authors: Sengupta Tapan Kumar
Published: April 2003

In the complete absence of a systematic polymer nomenclature, a scheme of nomenclature based on structure is proposed. The problem of naming a “mer” has been solved for an addition polymer by adding “ne” to the monomer name, the justification being on withdrawal of a π bond a monomer becomes a mer. To furnish completeness to the nomenclature, condensation polymers were included in the system. The present nomenclature system of polymers is very arbitrary. Some polymers are not chemically named, some named incorrectly, and there are some fantastic names. After pointing these out, the possible solutions were shown, encompassing a systematic discussion on nearly every type of polymer–linear, branched, or crosslinked–and copolymer (including block or graft), and plastic, fiber, or rubber, and stereospecific polymer. One or more names were proposed for different cases.
13C‐NMR study of cellulose derivatives in the solid state
Authors: Hoshino M. , Takai M. , Fukuda K. , Imura K. , Hayashi J.
Published: April 2003

The application of NMR for natural organic compounds has been carried out from the early history of NMR. But they reported on the liquid state NMR and the samples were limited to the materials which dissolved in proper solvents. It has been possible to measure the samples in the solid state in 1970s and is widely used as a familiar analytical method in 1980s. Whereas some of the data is inadequate, concerning cellulose derivatives, in particular, only nitrate and acetate were reported by Patterson1 and Doyle,2 respectively. In this paper, the 13C CP/MAS solid state NMR spectra of several cellulose derivatives are shown and the relationship between the structure and spectrum is discussed.
A novel insertion reaction of epoxy compounds into phenyl ester linkages in polymer chains
Authors: Nishikubo Tadatomi , Shimokawa Tutomu , Hirano Toshiyuki , Shiina Atushi
Published: April 2003

The insertion reaction of various epoxy compounds such as phenyl glycidyl ether (PGE), methyl glycidyl ether, butyl glycidyl ether (BGE), and styrene oxide into the phenyl ester linkage in the polymer chain was investigated using quaternary ammonium salts as catalysts in diglyme, anisole, sulfolane, o‐dichlorobenzene, or DMSO at 100–150°C. The reaction of PGE with poly[4‐(4‐nitrobenzoyloxy)styrene] (polymer 1a) proceeded almost quantitatively to give the corresponding polymer using tetrabutylammonium bromide (TBAB) as catalyst in diglyme at 100°C for 24 h. The reactions of BGE with poly(4‐nitrophenyl methacrylate), and copolyarylate derived from 2,2‐bis(4‐hydroxyphenyl)‐1,1,1,3,3,3‐hexafluoropropane and iso‐ and terephthaloyl chlorides also produced the corresponding polymers with 86 and 89 mol% new structural units, respectively, using TBAB in sulfolane at 150°C for 24 h. Furthermore, it was found that the degree of insertion of the epoxy compound into the ester linkage in the polymer chain was affected by the kind of epoxy compound, reaction solvent, catalyst concentration, substituent group on the phenyl ester, and structure of the polymer. Chiral polymers were also synthesized with high degrees of insertion by the reaction of chiral epoxides such as (R)‐1,2‐epoxyhexane, (R)‐1,2‐epoxyheptane, and (R)‐1,2‐epoxydecane with polymer 1a and poly(2,4‐dichlorophenyl methacrylate) using TBAB in diglyme at 120°C for 24 h.
Functional metallomacrocycles and their polymers. XXII. Thermally stable metallophthalocyanine formaldehyde condensation resins
Authors: Itoh H. , Masuda E. , Koyama T. , Hanabusa K. , Shirai H. , Kurose A. , Takemoto K.
Published: April 2003

A novel class of urea‐formaldehyde condensation resins containing covalently bound metallophthalocyanine [M = A1(III), Co(II), Ni(II), or Cu(II)] was synthesized from [tetrakis(methyl‐olamide)phthalocyaninato] metal complexes and dimethylolurea in aqueous solution by heating at 120°C for 10 h, followed by heating at 150°C for about 1 day. The structures of the polymers obtained were characterized by infrared and reflection electronic spectra. The thermal stabilities of the resins were evaluated by dynamic thermogravimetric analyses. The resin containing 21.3 wt % Ni(II)‐metallophthalocyanine had the greatest thermal stability, with 82 wt‐% char yield at 600°C in air atmosphere.
Thermal decomposition processes in aromatic polythiocarbonates
Authors: Montaudo Giorgio , Puglisi Concetto , Berti Corrado , Marianucci Elisabetta , Pilati Francesco
Published: April 2003

The thermal degradation of some polythiocarbonates obtained from bisphenol A bischloroformate and dithiols have been investigated by thermogravimetry and by direct pyrolysis in the mass spectrometer operating both in electron and chemical ionization. Poly(bisphenol A‐co‐tri‐methylenedithiocarbonate) decomposes by an intramolecular exchange process (back‐biting) producing trimethylene‐1,3‐dithiocarbonate and bisphenol A polycarbonate. The latter undergoes further thermal degradation at higher temperature yielding cyclic oligomers. Polymers containing tetramethylene‐1,4‐dithiocarbonate and hexamethylene‐1,6‐dithiocarbonate units decompose by the same mechanism, but the elimination of the dithiocarbonate units is not as fast and selective as the previous case. Some bisphenol A units are eliminated in the first thermal degradation stage and a rearrangement reaction producing ether linkage also occurs. Poly(phenylene‐1,3‐dithiocarbonate) decomposes by CO and COS loss with formation of sulfide and disulfide bridges along the polymer chains, which undergo further thermal degradation by a back‐biting process yielding a series of cyclic compounds. The thermal degradation of Poly(bisphenol A‐co‐phenylenedithiocarbonate) takes place through an interchange reaction producing phenylene‐1,3‐dithiocarbonate sequences which further decompose as the corresponding polymer. The remaining bisphenol A polycarbonate decomposes at higher temperature producing cyclic carbonates.
Synthesis and characterization of poly[N‐((10‐phenothiazinyl)‐6‐hexanoyl)ethylenimine] and N,N‐diethyl‐6‐(10‐phenothiazinyl)‐hexanamide
Authors: Kim Jinbaek , Litt Morton H.
Published: April 2003

A new oxazoline monomer was made containing a chloroalkyl substituent which can be transformed to other functional groups by nucleophilic substitution. Oxazoline monomer containing the N‐phenothiazinyl substituent was made by reacting lithiated phenothiazine with the chloroalkyl substituted oxazoline and subsequently polymerized. N,N‐diethyl‐6‐chlorohexanamide was synthesized and N,N‐diethyl‐6‐(10‐phenothiazinyl)‐hexanamide, a model compound for the phenothiazine polymer, was made by reacting lithiated phenothiazine with this chloroamide. TCNQ did not complex with the polymer. The iodine and perchlorate complexes of the phenothiazine polymer had conductivities of 4.4 × 10 −8 and 6.9 × 10−6 S/cm, respectively, at room temperature. Each of these are higher than the corresponding values reported for complexes of the analogous model compounds or 3‐substituted phenothiazine polymer reported earlier.13, 22 This was attributed to the very short chain repeat distance for the present, symmetrically substituted polymer.
Structural aspects of polyimides. I. Polymerization and degradation of endo‐N‐phenylnadimide and endo‐N‐isobutylnadimide
Authors: Vijayakumar C. T. , Lederer K. , Kramer A.
Published: April 2003

The isomerization, polymerization, and degradation aspects of endo‐N‐phenylnadimide and endo‐N‐isobutylnadimide (NPNI‐N and NIBNI‐N) were investigated using infrared analysis (IR), differential thermal analysis (DTA), gel permeation chromatography (GPC), thermogravimetric analysis (TG), and capillary gas chromatography‐mass spectroscopic (GC–MS) techniques. Although the endotherm related to the retro‐Diels–Alder reaction is not registered in the DTA thermographs, on‐line mass spectrometric studies revealed the occurrence of this process. The formation of the Diels–Alder adduct of cyclopentadiene with N‐isobutylnadimide (NIBNI) during the polymerization of NIBNI‐N is proved. GPC studies on NPNI‐N and NIBNI‐N cured at 300°C for 3.0 h showed the average degree of polymerization to be three to four. The polymers obtained by curing NPNI‐N and NIBNI‐N at 300°C for 3.0 h showed 109.8 kJ/mol as the activation energy for degradation. The dynamic and isothermal pyrolysis studies clearly indicated the presence of intact norbornyl units in the polymer, and the breakage of CH2 bridges in the strained norbornyl structural elements was found to be the point of aromatization during degradation.
Thermal deesterification and decarboxylation of alternating copolymers of styrene with β‐substituted t‐butyl α‐cyanoacrylates
Authors: Ito Hiroshi , Padias Anne B. , Hall H. K.
Published: April 2003

Alternating copolymers of styrene with β‐carboalkoxy‐substituted t‐butyl α‐cyanoacrylates undergo facile deesterification at 150–190°C, about 60°C below the deprotection temperature of poly(t‐butyl methacrylate), and decarboxylation at 170–200°C. When the β‐substituent is a methyl ester, the two events are clearly separated, with the deesterification occurring at a maximum rate at 165°C and decarboxylation at 193°C. Anhydride formation is negligible in this case. The copolymer with t‐butyl cyanofumarate exhibits simultaneous deesterification and decarboxylation events at 180°C with concomitant minor dehydration.
A rapid method for the determination of Mark–Houwink constants from GPC and viscosity data on a single sample
Authors: Price G. J. , Moore J. W. , Guillet J. E.
Published: April 2003

A straightforward and rapid method for the determination of Mark–Houwink constants from GPC and viscometry is described. A single original polymer is sufficient since other samples were prepared by sonication. The use of a number of samples in this way is shown to improve the accuracy over determinations where only two polymer samples are used.
Zerovalent metal polymer composites. I. Metallized beads
Authors: Warshawsky A. , Upson D. A.
Published: April 2003

Binding of a noble metal salt, e.g., PdCl to a functional ligand on a polymer surface, e.g., amine, quaternary ammonium, sulphonic acid, followed by reduction to zerovalent state and subsequent reductive deposition of transition metal ions, such as copper, nickel, and cobalt, provides a sequence of events leading to controlled zerovalent metal polymer composites. Metallization of submicron and larger beads are described. Large amounts of metal can be incorporated. The metallized beads retain the shape of the starting beads, even at high bonding of metal. They adapt the properties of the metal, e.g., magnetic properties. The submicron particles are sensitive to hydrolysis. Multicomponent systems, such as multimetallic beads, are provided by additive codeposition of metal ions, or by codeposition of metal and dye. Direct deposition of metal to preimmobilized dye ligands is also possible, leading to magenta, cyan, or yellow metallic beads, with no adverse influence on the magnetic properties. Further deposition of noble metals by subtractive deposition on active metal surfaces is also described. Submicron latices can be immobilized by coating on polyester‐based films, e.g., KODAK ESTAR base, and then activated with palladium and metallized to form highly conductive film surfaces.
The products of the reaction of polyphenylene sulfide with SO3 and SOCl2
Authors: Montoneri E.
Published: April 2003

Two polymer fractions, respectively with 28–38% and 6–9% sulphonated (SO3H) phenylene rings, may be isolated in the solid‐liquid reaction between p‐polyphenylene sulfide and SO3 in refluxing dichloroethane‐liquid SO2. The products relative yield depends on the experimental conditions of the reaction. No solvent has been found for these polymers.

The reaction of the sulphonated polymers with SOCl2 leads to formation of higher substitution products containing both and functional groups. The polymers in chlorophenyl phenylsulphonylchloride form are soluble in excess SOCl2 and/or CHCl3, depending upon the concentration of ring chlorine.

The mechanism of sulphonation in the heterogeneous medium and the presence of cross‐links in the reaction products are discussed.
Ring‐opening polymerization of 1‐(p‐substituted phenyl)‐2‐vinylcyclopropanes by Ziegler–Natta catalysts
Authors: Cho Iwhan , Song Soo Suk
Published: April 2003

1‐(p‐Substituted phenyl)‐2‐vinylcyclopropanes such as 1‐phenyl‐2‐vinylcyclopropane (Ia), 1‐(p‐chlorophenyl)‐2‐vinylcyclopropane (Ib), 1‐(p‐anisyl)‐2‐vinylcyclopropane (Ic), and 1‐(p‐tolyl)‐2‐vinylcyclopropane (Id) were prepared and polymerized radically, cationically and with Ziegler–Natta catalysts. Ia and Ib polymerized exclusively in 1,5‐fashion with radical initiators. However, Ic and Id polymerized in 1,5‐fashion only with Ziegler–Natta catalysts. All polymers were soluble in ordinary organic solvent and solution‐cast films were clear and flexible, showing Tg values in the range of 39–71°C. Spectral data indicated that the double bonds of the polymer chains were in trans form in all cases. The difference between the polymerizabilities of different monomers are interpreted in terms of electronic properties of substituents.
Attaching chelating ligands to polybenzimidazole via epoxidation to obtain metal selective sorbents
Authors: Chanda M. , Rempel G. L.
Published: April 2003

Microporous polybenzimidazole of 250–500 μm spherical bead size from Celanese has been reacted with epichlorohydrin and sodium hydroxide and the resulting product with pendant epoxy groups has been reacted with various chelating ligands in order to augment the metal sorption capacity and selectivity of the resin. The chelating ligands used include ethylenediamine, diethylenetriamine, diethanolamine, dimethylglyoxime, L‐cysteine, thiourea, dithiooxamide, glyoxal‐bis‐2‐hydroxyanil, salicylaldehyde‐ethylenediimine, and glyoxal‐bis‐2‐mercaptoanil. The aminolysis of the pendant epoxy groups with the oligoamines has been performed in pyridine under reflux conditions, while the addition reactions with the other ligands which are alkali soluble have been carried out at room temperature in a mixture of dioxane and aqueous KOH using tetra‐n‐butylammonium iodide as the phase transfer catalyst. The products are found to possess high capacity and selectivity in metal sorption depending on the ligand attached.
Preparation and properties of fluorine‐containing aromatic polyamides from tetrafluorophthaloyl chlorides and aromatic diamines
Authors: Oishi Yoshiyuki , Harada Shigeyuki , Kamimoto Masa‐Aki , Imai Yoshio
Published: April 2003

New fluorine‐containing aromatic polyamides with inherent viscosities of 0.4–1.8 dL/g were prepared by the low temperature solution polycondensation of tetrafluoroisophthaloyl and tetrafluoroterephthaloyl chlorides with N,N′‐bis(trimethylsilyl)‐substituted aromatic diamines. The aromatic polyperfluoroisophthalamides were amorphous polymers with glass transition temperatures around 280°C, whereas the polyperfluoroterephthalamides were crystalline. Most of these aromatic polyamides were soluble in organic solvents, and began to decompose around 330°C in air or nitrogen atmosphere.
Investigation of the formation of poly(ethylene terephthalate) with model molecules. III. Metal‐catalyzed esterification and alcoholysis reactions: Influence of the structure of the reactants and of the nature of the reaction medium
Authors: Otton Jean , Ratton Serge , Vasnev Valerii A. , Markova Gali D. , Nametov Kahirman M. , Bakhmutov Vladimir I. , Vinogradova Svetlana V. , Korshak Vasilii V.
Published: April 2003

With a reaction conducted on model molecules with low amounts of catalysts and at low temperatures (170–225°C), it was shown that esterification is mainly catalyzed by the carboxylic acid groups and by the titanium derivatives; the activity of the other metals can only be seen when the concentration in carboxylic acid groups is low. In the alcoholysis reaction, the activity of Zn, Mn, and (much less) Ti, decreases when the percentage of ester in the reaction medium decreases, whereas it is the opposite with Sb. Moreover, Zn, Mn, and Co are sensitive to trace amounts of carboxylic groups (their activity decreases), whereas Ti is much less affected.
Syntheses of 4‐methacryloxy‐2,3,5,6‐tetrabromobenzyl phosphonates and effects of flame retardancy on their Co‐PMMA
Authors: Yang Chin‐Ping , Wang Sheng‐Sung
Published: April 2003

4‐Methacryloxy‐2,3,5,6‐tetrabromobenzyl phosphonates (MTBBP) are prepared by the reaction of corresponding 4‐hydroxy‐2,3,5,6‐tetrabromobenzyl phosphonates (HTBBP) with methacryloyl chloride. Comparisons of flame retardancy among the copolymers of methylmethacrylate (MMA) with MTBBP or with 4‐methacryloxy‐2,3,5,6‐tetrabromotoluene(MTBT) and the mixture of poly(methyl methacrylate) (PMMA) with triphenyl phosphite reveal that the combination of phosphorus and bromine elements produces a synergistic effect on flame retardancy, and the chemical grafting of the fire‐resistant elements into the polymer backbone gives a better effect than the physical mixing of their compounds with polymer. The unsatisfactory results of homopolymers of the synthesized methacrylate monomers prepared by free radical polymerization in solution may be due to their less reactivities; however, they can readily copolymerize with a liquid vinyl monomer such as MMA by means of bulk polymerization.
The free radical distribution in emulsion polymerization using oil‐soluble initiators
Authors: Asua J. M. , Rodriguez V. S. , Sudol E. D. , El‐Aasser M. S.
Published: April 2003

A new approach is presented to calculate both the distribution of particles with iradicals and the average number of radicals per particle in emulsion polymerizations carried out using oil‐soluble initiators. The convergence and accuracy of the approach were examined. It was found that, in agreement with previously published experimental results, the present approach predicts a kinetic behavior similar to that found for water‐soluble initiators. This effect is primarily due to the desorption of initiator radicals from the polymer particles rather than the contribution of the fraction of oil‐soluble initiator dissolved in the aqueous phase.
A study on the plasma polymerization of some cyano‐containing compounds and their electrical properties
Authors: Osada Y. , Yu Q. S. , Yasunaga H. , Kagami Y. , Wang F. S. , Chen J.
Published: April 2003

Plasma polymerization of some cyano‐containing organic compounds was carried out at 13.56 MHz from the gas phase. The resulting polymer films were smooth and pinhole free. The electrical conductivities of the polymer films varied from 10−12 to 10−7 S cm−1 depending upon which cyano‐containing monomer was used. The Al/polymer film/ITO (indium‐tin oxide) sandwich cells made from the films demonstrated a photovoltaic effect, and some of them showed good rectifying behavior. Infrared spectroscopy (IR) and ultraviolet spectroscopy (UV) were utilized to characterize the structure of the product polymers. The effects of the original structure in the starting monomers on the structure of the resulting polymers are investigated. The influence of incident light intensity on the photovoltaic characteristics was also investigated.
Radical polymerization of styrene initiated by styrene–arsenic sulfide complex
Authors: Shukla Prerna , Srivastava A. K.
Published: April 2003

Styrene forms a complex with arsenic sulfide which in DMF at 85°C initiates radical polymerization yielding high molecular weight polymer. The order of reaction, with respect to initiator and monomer, is 0.5 ± 0.02 and unity, respectively. The energy of activation for the system computed as 96 kJ mol−1 and the polymerization is retarded by hydroquinone. A possible mechanism for reaction has also been proposed.
Investigation of the ceriumIV oxidation of poly(vinyl alcohol)
Authors: Storey Robson F. , Goff Leslie J.
Published: April 2003

Initiation of ceric ion‐induced grafting from poly(vinyl alcohol) (PVOH) was studied by examining the formation and lifetime of colored complexes between ceriumIV and (1) a commercial PVOH, (2) a diol‐free PVOH, and (3) several model 1,2‐diols. UV/visible spectroscopy was employed using a wavelength of 520 nm. Results showed that the 1,2‐diols, which are an inherent defect in PVOH, are the sites most reactive toward ceric ion. The observed rate constant for the reaction was found to increase with decreasing [CeIV] until the maximum rate was reached at which time reaction took place exclusively with 1,2‐diols. The activation energy for oxidation of commercial PVOH at the maximum rate was 15.4 kcal/mol while that for diol‐free PVOH was 22.4 kcal/mol. The 1,2‐diols of PVOH displayed a high equilibrium constant for complexation with ceric ion, compared to the model 2,3‐butanediol. It was suggested that the PVOH chain segments bring about crowding of the diol group, and this leads to a higher equilibrium constant for complexation. The lowest energy conformation of a PVOH chain segment containing a 1,2‐diol linkage was calculated using the CHEMLAB‐II molecular design program, and the 1,2‐diol was predicted to be at the center of a sharp bend in the chain brought about by its presence.
Preparation and properties of some water‐soluble, comb‐shaped, amphiphilic polymers
Authors: Wesslén Bengt , Wesslén K. Bodil
Published: April 2003

Water‐soluble comb‐shaped polymers were prepared through grafting of poly(ethylene glycol) monomethyl ethers (MPEG) onto acrylic and methacrylic ester copolymers by transesterification reactions. The grafting was alkali‐catalyzed, and performed in refluxing toluene solution or in melt at 155°C. The grafting efficiency was found to be on the order of 1 graft/10 monomer units. Epoxy groups in glycidyl methacrylate copolymers were also utilized for grafting. The crude graft copolymers were purified through chromatography and characterized by NMR and IR spectroscopy. Polymers prepared from MPEG 2000 were crystalline with melting points 10–15°C lower than the MPEG used. All polymers were shown to be surface active with CMC on the order of 1.5 g/L, and surface tensions of 38–45 dyn/cm. When used as emulsifiers the graft copolymers containing bulky lipophilic ester groups (2‐ethylhexyl t‐butyl) gave oil‐in‐water (o/w) and water‐in‐oil (w/o) emulsions from xylene/water with higher stability than those containing straight chain ester groups (methyl nbutyl n‐docecyl). The most stable emulsions were obtained by dissolving the polymers in the organic phase.