Structure and Content of Dicyclopentadiene in Ethylene Propylene Dicyclopentadiene Terpolymers

1967 ◽  
Vol 40 (2) ◽  
pp. 563-568
Author(s):  
R. J. de Kock ◽  
A. Veermans
Keyword(s):  
Double Bond ◽  
Polymer Chain ◽  
Spectroscopic Methods ◽  
Double Bonds ◽  
Model Compounds ◽  
Ethylene Propylene ◽  
Infrared Spectroscopic ◽  
Polymerization Mixture ◽  
Derivatives Of

Abstract With the aid of model compounds—derivatives of endo- and exo-dicyclopentadiene—it has been established that a) the 9, 10-double bond (the double bond in the norbornane ring) is involved in the polymerization of dicyclopentadiene with ethylene and propylene, b) dicyclopentadiene, present in the polymerization mixture in the endo-configuration, occurs in the exo-configuration in the polymer chain. The same model compounds enable the dicyclopentadiene content of ethylene propylene dicyclopentadiene terpolymers to be determined by infrared spectroscopic methods. Use is made of the 3045 cm−1 band, which is characteristic of endo-cyclic double bonds in five-membered rings.

Sulfur Vulcanizable Ethylene-Propylene Rubbers

1963 ◽  
Vol 36 (4) ◽  
pp. 988-999 ◽  
Author(s):  
Giulio Natta ◽  
Giorgio Mazzanti ◽  
Giovanni Crespi ◽  
Alberto Valvassori ◽  
Guido Sartori
Keyword(s):  
Double Bond ◽  
Polymer Chain ◽  
Double Bonds ◽  
Rubber Industry ◽  
Ethylene Propylene ◽  
Homogeneous Composition ◽  
Interesting Solution

Abstract Our research directed to obtaining new rubbers based on the copolymerization of ethylene with propylene started some years ago. We soon succeeded in establishing that it was possible to prepare copolymers of these two monomers showing interesting elastomeric properties. From the beginning, the problem arose of how to vulcanize these copolymers: while certain interesting methods for direct vulcanization were investigated and identified, we also investigated the possibility of terpolymers containing unsaturation and therefore vulcanizable with the ingredients normally employed in the rubber industry, particularly for the low unsaturated rubbers. The problem involved some difficulties, due to the following three reasons. (1) In order to maintain the peculiar characteristics of resistance to aging and chemicals, typical of ethylene-propylene copolymers, it was necessary to obtain terpolymers in which the unsaturation was present in a very small amount. (2) To obtain valuable properties in the vulcanizates, the unsaturation had to be well distributed in all the macromolecules. (3) In order to avoid branching or crosslinks, the residual double bond of the diene entering the polymer chain must not be able to react further during polymerization. Our research led to a number of monomers which may copolymerize with ethylene and propylene and which, under suitable conditions, gave terpolymers having a sufficiently homogeneous composition. Investigation of the behavior, in anionic coordinated polymerization of hydrocarbons containing internal double bonds led to an interesting solution to the problem of producing terpolymers.

scholarly journals Phenolation of vegetable oils

2011 ◽  
Vol 76 (4) ◽  
pp. 591-606 ◽  
Author(s):  
Mihail Ionescu ◽  
Zoran Petrovic
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Double Bond ◽  
Vegetable Oils ◽  
Raw Materials ◽  
Complex Mixture ◽  
Double Bonds ◽  
Triflic Acid ◽  
Model Compounds ◽  
Phenol Alkylation

Novel bio-based compounds containing phenols suitable for the synthesis of polyurethanes were prepared. The direct alkylation of phenols with different vegetable oils in the presence of superacids (HBF4, triflic acid) as catalysts was studied. The reaction kinetics was followed by monitoring the decrease of the double bond content (iodine value) with time. In order to understand the mechanism of the reaction, phenol was alkylated with model compounds. The model compounds containing one internal double bond were 9-octadecene and methyl oleate and those with three double bonds were triolein and high oleic safflower oil (82% oleic acid). It was shown that the best structures for phenol alkylation are fatty acids with only one double bond (oleic acid). Fatty acids with two double bonds (linoleic acid) and three double bonds (linolenic acid) lead to polymerized oils by a Diels Alder reaction, and to a lesser extent to phenol alkylated products. The reaction product of direct alkylation of phenol with vegetable oils is a complex mixture of phenol alkylated with polymerized oil (30-60%), phenyl esters formed by transesterification of phenol with triglyceride ester bonds (<10 %) and unreacted oil (30%). The phenolated vegetable oils are new aromatic-aliphatic bio-based raw materials suitable for the preparation of polyols (by propoxylation, ethoxylation, Mannich reactions) for the preparation of polyurethanes, as intermediates for phenolic resins or as bio-based antioxidants.

The Vulcanization of Highly Elastic Polymers. 81. Sulfur Vulcanization of Ethylene-Propylene Terpolymers Containing Varying Amounts of Double Bonds

1975 ◽  
Vol 48 (5) ◽  
pp. 889-895
Author(s):  
W. Scheele ◽  
S. Fleige
Keyword(s):  
Double Bond ◽  
Supermolecular Structure ◽  
Stoichiometric Ratio ◽  
Technological Properties ◽  
Sulfur Concentration ◽  
Double Bonds ◽  
Ethylene Propylene ◽  
Rate Laws ◽  
Chemical Constitution ◽  
Double Bond Content

Abstract The results of unaccelerated and accelerated vulcanizations of ethylene-propylene terpolymers (EPDM) demonstrate that the reaction of sulfur with allyl systems (such as those which the 1,5-polyenes contain at concentrations far exceeding the quantity of sulfur introduced for crosslinking purposes) tends toward an order above unity and eventually towards second order, as the sulfur concentration and the double bond content approach the stoichiometric ratio. This could be shown with unaccelerated vulcanizations of EPDM in the absence of ZnO, as well as those accelerated by zinc mercaptobenzothiazole. This is so, in our opinion, because in the one case autocatalysis by the polysulfidic sulfur is inhibited, and in the other it becomes negligible because of the very rapid reaction rate. According to Scheele and Huischen, the reaction order for sulfur decrease for the unaccelerated vulcanization of nitrile rubber is first order, both with respect to time and (very important!) with respect to concentration (nt=no=1), and the reaction is not subject to autocatalysis because of disulfidic crosslinks. Accordingly, we arrive at the conviction, in view of the relations obtained with the EPDM rubbers, that all the rate laws determined for sulfur decrease in 1,5-polyene vulcanizations with an excess of double bonds have as their basis pseudo-reaction orders or pseudo-molecularities. In spite of these generally revealing differences in the kinetics of sulfur decrease and in its chemistry between the 1,5-polyenes with their excess of double bonds and the EPDM rubbers with double bond content that is commensurate with the sulfur concentration, the fact still remains that the reaction of sulfur with polymers containing allyl groups has all the characteristics of a multistep reaction of of catalysis by an intermediate and that these characteristics are obviously those generally found in reactions between sulfur and any kind of compound that contains allyl groups. Even the great differences observed between the chemical constitution and the macromolecular structure of the various homo- and copolymers of the 1,3-dienes (natural rubber and poly butadiene), of polypentenamer, and of the EPDM rubbers under consideration here, cannot alter that circumstance, since each situation involves an analogous reaction of sulfur with the allyl units which sulfur-crosslinkable rubbers contain. Any quantitative differences noted can be attributed to the concentration ratios of all the participating reactants as well as the chemical constitution and reactivity of the allyl units. Thus one cannot escape the conclusion that the submolecular, molecular, and supermolecular structure of the rubbers, as well as the polymerization degree and the molecular weight distribution, are of greater importance for the physical, mechanical, and technological properties of the vulcanizates than the vulcanization itself, which, incidentally, should always be carried out so as to realize optimum technological properties in order to meet the industrial technological requirements.

Structure of Ethylene Propylene Dicyclopentadiene Terpolymers

1966 ◽  
Vol 39 (4) ◽  
pp. 964-968
Author(s):  
W. Cooper ◽  
D. E. Eaves ◽  
M. E. Tunnicloffe ◽  
G. Vaughan
Keyword(s):  
Double Bond ◽  
Infrared Spectra ◽  
Ring Opening ◽  
Iodine Monochloride ◽  
Model Compounds ◽  
Ethylene Propylene

Abstract Terpolymers of ethylene, propylenc and C14-dicyclopentadiene have been compared with model compounds to determine the structure of combined termonomer units. Reactions with iodine monochloride, bromine and the infrared spectra of the terpolymers indicate that dicyclopentadiene polymerizes at the 9,10 double bond without ring-opening or disproportionation.

scholarly journals Refractive dispersion of organic compounds. V-Oxygenated derivatives of cyclohexane the inadequacy of the Ketteler-Helmholtz equation

1934 ◽  
Vol 146 (857) ◽  
pp. 300-312 ◽  
Keyword(s):  
Double Bond ◽  
Preceding Paper ◽  
Hydroxyl Group ◽  
Double Bonds ◽  
Ring Compounds ◽  
Wide Range ◽  
Olefinic Double Bond ◽  
The One ◽  
Conjugated Compounds ◽  
Derivatives Of

In the preceding paper of this series, refractive indices and molecular extinction coefficients over a wide range of wave-lengths were recorded for the two cyclic hydrocarbons cyclohexene and 1:3- cyclohexadiene . These observations completed a study of the refractive dispersions of the series of 6-ring compounds C 6 H 12 , C 6 H 10 , C 6 H 8 , C 6 H 6 ; they also provided a basis for the study of the phenomenon of "optical exaltation," which is exhibited by compounds containing conjugated double bonds, since the last two members of the series belong to this type. Conjugation, however, may be effected, not only between two olefinic double bonds, but also between an olefinic double bond and an oxygenated radical, such as the carboxyl, carbonyl, or hydroxyl group. The present paper, therefore, records the absorption spectra and refractive dispersions of three oxygenated derivated of cyclohexane, namely, cyclohexanol , cyclohexanone , and ethyl hexahydrobenzoate , in the molecules of which each of the preceding groups is exemplified. Dispersion curves are thus now available for typical compounds of the cyclohexane series containing "unsaturated" radicals of all the principal types which are used in constructing conjugated systems, and the way has been prepared for a detailed study of conjugation, as exemplified on the one hand by cyclo hexadiene, and similar compounds containing two olefinic radicals, and on the other hand by a variety of compounds containing a double bond in addition to a hydroxyl, carbonyl, or carboxyl group. It is anticipated that, with the help of the date set out in the preceding and present papers, it will be possible in a later communication to demonstrate in what respect the behaviour of conjugated compounds differs from that which might be anticipated from a merely additive behaviour of the chromophoric radicals, and thus to determine the nature, and if possible to discover the origin, of the phenomenon of optical exaltation.

Determination of Double Bonds in Ethylene Propylene Terpolymer Rubbers

1967 ◽  
Vol 40 (3) ◽  
pp. 936-946 ◽  
Author(s):  
R. Hank
Keyword(s):  
Double Bond ◽  
Conjugated Dienes ◽  
Butyl Rubber ◽  
Double Bonds ◽  
Ethylene Propylene ◽  
Qualitative And Quantitative ◽  
Considerable Success

Abstract Developments in the field of sulfur vulcanized unsaturated ethylene propylene terpolymer rubbers, also known as EPT rubbers, have progressed rapidly in recent years. Considerable success has been achieved in producing EPT rubbers from ethylene, propylene, and various dienes. Initial difficulties, involving introduction of double bonds into already known ethylene propylene copolymers, were soon overcome when it became clear that it was not the then commonly conjugated dienes such as butadiene and isoprene, but rather nonconjugated dienes, which were required for successful terpolymerization with ethylene and propylene, according to the Ziegler process. As with butyl rubber, it is sufficient, for vulcanization purposes, to incorporate one or two mole per cent of such dienes into the terpolymer. It is especially important, not only for polymerization, but also for rubber processing, to know the type and amount of unsaturation. In this article we wish first of all to report on double bond determinations in general and then, in particular, on qualitative and quantitative dicyclopentadiene determinations in ethylene propylene terpolymers. It is especially important, not only for polymerization, but also for rubber processing, to know the type and amount of unsaturation. In this article we wish first of all to report on double bond determinations in general and then, in particular, on qualitative and quantitative dicyclopentadiene determinations in ethylene propylene terpolymers.

Utility of the Cleavage of Nitrosamides for the Preparation of Chiral Acids after Chromatographic Separation of their Diastereomeric Amides

1977 ◽  
Vol 32 (1) ◽  
pp. 98-104 ◽  
Author(s):  
Franz P. Schmidtchen ◽  
Peter Rauschenbach ◽  
Helmut Simon
Keyword(s):  
Double Bond ◽  
Carboxylic Acids ◽  
Chromatographic Separation ◽  
Optical Resolution ◽  
Double Bonds ◽  
Reaction Conditions ◽  
Double Bond Migration ◽  
Enantiomerically Pure ◽  
Amide Derivatives ◽  
Derivatives Of

A method for optical resolution of chiral acids is described. It consists of the conversion of racemic acids to diastereomeric amides, their chromatographic separation and subsequent deamidation via the nitrosamide route. Reaction conditions for cleavage of amide derivatives of phenylalanine and methylbenzylamine are given. No or only negligible racemization of carboxylic acids, chiral in α-position takes place under those conditions. The extent of Ε,Ζ-isomerization of double bonds is very small, as is the extent of double bond migration from the Δ3-position into conjugation with the carboxyl function. Enantiomerically pure R- or S[2-3H]2-methylbutanoic acid and (-)methyl-3(p-chlorophenyl)-2-chloropropionate (Bidisin®) were prepared by this procedure.

Sirosterol and dehydroazasirosterol, unusual steroidal adducts from a Sirococcus species

1992 ◽  
Vol 70 (7) ◽  
pp. 1905-1913 ◽  
Author(s):  
William A. Ayer ◽  
Yu-Ting Ma
Keyword(s):  
Double Bond ◽  
Monomethyl Ether ◽  
Spectroscopic Methods ◽  
Model Compounds ◽  
Shoot Blight ◽  
Selective Hydroxylation

Two unusual compounds, which are made up of a sterol portion fused at C-5 and C-6 to an atrovenetin-like part, have been isolated from a fungus that causes Sirococcus shoot blight of spruce. The structures of these compounds, sirosterol (4) and dehydroazasirosterol (13), were determined by spectroscopic methods and comparison with appropriate model compounds. Sirosterol is an adduct of ergosterol and atrovenetin (5) and dehydroazasirosterol is an adduct of 9(11)-dehydroergosterol and an azaatrovenetin. Both compounds give a monomethyl ether when treated with diazomethane and both have been transformed to the corresponding 3-ketosteroids. The preparation of the triol 6 resulting from the selective hydroxylation of the 5,6-double bond in ergosterol is described. A possible biogenesis of sirosterol from ergosterol endoperoxide and a desoxyatrovenetin is discussed.

MNDO CI study of the photoisomerization of pentadieniminium

1990 ◽  
Vol 55 (12) ◽  
pp. 2874-2879 ◽  
Author(s):  
Peter Ertl
Keyword(s):  
Schiff Base ◽  
Double Bond ◽  
Configuration Interaction ◽  
Mndo Method ◽  
Double Bonds

Photoisomerization mechanism in model retinal-like protonated Schiff base pentadieniminium was investigated by using MNDO method with configuration interaction. Isomerizations around various double bonds were studied and twisted biradical geometries in S0 and S1 states were optimized. Photoisomerization proceeds exclusively around the central double bond where the twisted S1 state is strongly stabilized and the S0-S1 gap is minimal.

Sign in / Sign up

Export Citation Format

Share Document