摘要:

AbstractThermoplastic resins have been prepared by the reaction of formaldehyde and aroyl propionic acids derived from the succinoylation of aromatic hydrocarbons. A study has been made of the condensation reaction, and nuclear magnetic resonance (n.m.r.) spectroscopy has been found to be extremely useful in the elucidation of the reaction mechanism. Two types of initial reaction with formaldehyde have been shown to occur: firstly, attack at the aromatic nucleus to give a substituted benzyl alcohol (which may condense further); and, secondly, reaction at the CH2groups α to C = O groups leading to the formation of a γ‐lactone. The relative extents of the two reactions are determined by the activity of the aromatic nucleus to formaldehyde attack. In the case of resins from 2,4,6‐trimethylbenzoylpropionic acid, γ‐lactone formation is virtually absent and attempts have been made to consider the further condensation reactions of the substituted benzyl alcohol formed i

ISSN:0021-8871    

DOI:10.1002/jctb.5010171101

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010171108

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractCracking of methane in anomalous glow‐discharges in a small bench‐scale apparatus (25mm diameter, 42 mm inter‐electrode distance) at pressures of 20–80 torr, feed flow rates of 5–40 l/h and power inputs of 100–300 W has resulted in high degrees of total conversion (up to 98% on carbon basis) and acetylene formation (up to 60%). Dependence on these process variables of the formation of diffuse and concentrated discharges is described and the desirability of the latter for acetylene formation pointed out. The effect of the process variables on yields is complex, but for a given temperature or contact time, specific energy input is the underlying factor which determines yields. Electron‐activation plays an important role in the cracking reactions. The possibility of practical applications

ISSN:0021-8871    

DOI:10.1002/jctb.5010171102

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractMethods for the separation and identification by infra‐red absorption spectroscopy of styrene‐butadiene, acrylic, vinyl‐acrylic and polyvinyl acetate homopolymer and vinyl acetate‐dibutyl maleate copolymer in emulsion paints based on these materials are presented. Detailed procedures for their quantitative determination are di

ISSN:0021-8871    

DOI:10.1002/jctb.5010171103

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractCarbon‐14 tracer techniques have been used to measure directly the carbon deposition resulting from the radiolysis of methane by itself and in the presence of carbon dioxide, oxygen and graphite. It is shown that carbon deposition is increased in the presence of carbon dioxide and decreased in the presence of oxygen. at high carbon dioxide pressures (40 cm Hg) and high doses (>100 Mrad), the majority of the methane is decomposed to deposit. Irradiation of methane by itself produces less deposit than in the presence of graphite and there is an enhancement of the surface deposit compared with that within the bulk of the graphite.The results of the analyses for light hydrocarbons produced during methane radiolysis over a range of conditions are also briefly discusse

ISSN:0021-8871    

DOI:10.1002/jctb.5010171104

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractThe synthesis of formaldehyde and methanol from methane and water vapour initiated by a d.c. discharge has been carried out in a two‐phase gas‐liquid reactor in which liquid water was present as a pool covering one electrode. Decomposition reactions, responsible for the low energy efficiency, are limited by a shorter residence time of the soluble products in the gas phase. The experimental results, when compared with those obtained in the absence of water, show a considerable increase in the energy yi

ISSN:0021-8871    

DOI:10.1002/jctb.5010171105

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractThe presence of large quantities of Ca(OH)2in hydrated Portland cement suggests that a study of the length change‐sorption characteristics of Ca(OH)2in the form of compacts should provide useful information.Length change‐sorption data were obtained for water from 0 to 76% RH and various cycling experiments between 0 to 58 and 0 to 93% RH were performed during which length change data were obtained. Preliminary experiments were also performed in relation to the carbonatation of Ca(OH)2compacts.Large irreversible shrinkages were observed while repeatedly determining the isotherms during the cycling experiments and it is suggested that these were the result of ionic diffusion from the points of contact of crystallites and the pulling together of these crystallites by van der Waals forces.The carbonatation of calcium hydroxide also produced shrinkage and it is considered that this could also be due to van der Waals surface for

ISSN:0021-8871    

DOI:10.1002/jctb.5010171106

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractThe most important dissipative mechanisms contributing to hysteresis when a rubber is stretched to breaking point are discussed. A quantitative examination of the influence of hysteresis on the work required to break the rubber produces a sensitive criterion of failure for a number of rubbers with and without carbon‐black fille

ISSN:0021-8871    

DOI:10.1002/jctb.5010171107

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY