摘要:

This paper is concerned with the reaction of triphosphonitrilic chloride and ethylene glycol, and with the properties of the triphosphonitrilic glycol ester obtained. The reaction studied was a dehydrochlorination of triphosphonitrilic chloride with glycol by heating. The ester obtained from the reaction could be further hydrolyzed to produce ammonium chloride and ethylene chlorohydrin. It thus clarified the reaction mechanism of triphosphonitrilic chloride with ethylene glycol.

ISSN:0022-233X    

DOI:10.1080/00222338208077205

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The bond energy scheme is extended to nitrogen compounds by correlating experimental thermochemical data reviewed to 1980. Heats of formation and atomization energy terms are provided for bonds of nitrogen with other elements: H, C, O, N, S, and halogens. An overall precision of 3 kcal/mol was attainable at the best, which is rather low for chemical reaction kinetics purpose. This is attributable mainly to the intrinsically unpredictable bond energies of the nitrogen atom due to the “lone-pair” electrons participation in the valence bonding, rendering nitrogen bonds specific and less transferable. The nearest-neighbor interactions on nitrogen atom are also severe but predictable if sufficient energy terms are generated. The concept of ring strain in five-membered rings (about 5 × 2 kcal/mol in the background of thermochemical data) has been reviewed and amended by providing a special set of energy terms for the (C, O, N, S) -ring skeleton which is considered strain-free if the hydrogen atom is the only substituent. Heats of formation of some common molecular structures are predicted.

ISSN:0022-233X    

DOI:10.1080/00222338208077206

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A pentanuclear phenolic oligomer of uniform structure and molecular weight has been prepared by a known method of step-wise synthesis. The presence of intramolecular hydrogen bonding in this compound has been well established. Interactions of some transition metal ions (e.g., Fe3+, Cu2+, Co2+) with this chelating oligomer have been studied by conductance, EMF, and optical density measurements in nonaqueous media. Interpretations of the results have been sought in terms of charge on the metal ion as well as charge on the ligand molecule.

ISSN:0022-233X    

DOI:10.1080/00222338208077207

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Neat polymerization of bisphenol-linked phthalonitrile monomers, which contain no active hydrogen atoms, is extremely difficult and requires several days of continuous heating at 260–290°C before a viscosity increase becomes evident. In the presence of a nucleophilic compound such as an organic amine, the cure time and temperature can be greatly reduced. The amine-cured polymers are more thermally stable than their neat cured counterparts. Preliminary results indicate that the amine causes no significant changes in the mechanical properties of the cured polymer. The bisphenol-linked phthalonitrile resins are particularly appealing as matrices for composite formulations due to the projected low material cost, the greatly improved processability, and the nonreactivity of the prepolymer at ambient temperature.

ISSN:0022-233X    

DOI:10.1080/00222338208077208

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Friedel-Crafts self-polycondensation of 4,4′-dichloromethyl-diphenyl ether (DDE) is studied under various experimental conditions. These polymer samples are infusible and are insoluble in all solvents. The polymer samples, PDs, are characterized by elemental analysis, IR spectral study, and by TGA. Polymer reaction products of one polymer sample are prepared by subjecting it to Friedel-Crafts reaction with excess benzene and by treating it with triethylamine. Both the polymer reaction products are found to be less stable than the parent polymer sample.

ISSN:0022-233X    

DOI:10.1080/00222338208077209

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A study of copolymerization of castor oil prepolymers (COP) with styrene has been made at 75°C using benzoyl peroxide as initiator. It has been found that good yields of copolymers (high molecular weightMn= 123,989) are obtained at a low concentration of COP. With an increasing concentration of COP in the binary mixture, copolymers with decreasing molecular weight are obtained. This is explained as due to presence of a high percentage of oxygen (from COP) in the system which is acting as a chain transfer agent.

ISSN:0022-233X    

DOI:10.1080/00222338208077210

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A novel polyamideimide was synthesized by reacting p,p′-di-(amino phenyl) sulfone and N-(p-carboxy phenyl) trimellitimide or its diacid chloride derivative. The polymer was found to be soluble in highly polar solvents. The polymer was characterized by elemental analyses and IR spectrum. It is found to be amorphous and of low molecular weight. The polymer is fairly thermostable, having a T of 210–220°C. Thermogravimetric determination revealed that the polymer underwent 17% weight loss at 375°C in air. The dielectric constant of the polymer at 1 kHz was 3.74 at 30°C. The electrical conductivity of the polymer was also measured.

ISSN:0022-233X    

DOI:10.1080/00222338208077211

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Two alkyl-substituted cyclic ketene acetals, 4-n-hexyl-2-methylene-1,3-dioxolane (4) and 4-n-decyl-2-methylene-1,3-dioxolane (6), were shown to undergo free radical ring-opening polymerization with the introduction of an ester group into the backbone of an addition polymer. The spontaneous polymerization of4(presumable by an ionic mechanism) produced a polymer containing no ring-opened units; furthermore4and6could be stabilized with respect to spontaneous polymerization by the addition of small amounts of pyridine. On the other hand, the polymerization of 4 in a 50% (by weight) benzene solution at 110°C with di-tertbutyl peroxide as the catalyst gave quantitative ring opening to give a polyester containing both possible isomeric ring-opened units. Bulk polymerization of4at 60°C at 53% conversion gave 50% ring opening which was divided 31% to 19% between cleavage to give the intermediate secondary free radical and the intermediate primary radical. Copolymerization of4with equimolar quantities of styrene at 110°C gave at 56% conversion a copolymer consisting of 67% styrene units, 22% ester-containing units resulting from cleavage to form a secondary radical, 7% of the isomeric ester-containing units, and 4% nonring-opened units. Polymerization studies with monomer6gave results very similar to those obtained with4.

ISSN:0022-233X    

DOI:10.1080/00222338208077212

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The graft copolymerization of methyl methacrylate onto poly-(ethylene terephthalate) using metal complexes of Mn3+, Co3+, and Fe3+as initiators was studied. The rate of polymerization, Rp, increased with increasing complex concentrations.

ISSN:0022-233X    

DOI:10.1080/00222338208077213

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Kinetics of polymerization of methyl methacrylate initiated by Mn3+/1,2-propanedlol has been investigated in aqueous sulfuric acid at the temperature range of 25–35°C. The rate of polymerization (Rp) and the rate of manganic ion disappearance (-RMn) have been computed. The effects of organic solvents, certain cationic and anionic detergents, added electrolytes on the initial rate of polymerization, and maximum conversion have been examined. Depending on the kinetic results, a reaction scheme has been suggested involving the formation of a complex between Mn3+and the alcohol, which subsequently decomposed in an unimolecular step to generate the initiating free-radical which initiates polymerization and termination of the growing polymer chain by metal ion.

ISSN:0022-233X    

DOI:10.1080/00222338208077214

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor