Terpolymers of Ethylene, Propylene, and Tricyclo [5.2.1.0]Deca-2,5,8-Triene

1975 ◽  
Vol 48 (4) ◽  
pp. 747-764
Author(s):  
S. Cesca ◽  
S. Arrighetti ◽  
A. Priola ◽  
P. V. Duranti ◽  
M. Bruzzone
Keyword(s):  
Chain Transfer ◽  
Lewis Base ◽  
Side Reactions ◽  
Conjugated Diene ◽  
Ethylene Propylene ◽  
Diene System ◽  
Methyl Derivatives ◽  
Low Levels ◽  
Catalyst Systems ◽  
Acid Character

Abstract Tricyclo[5.2.1.0]deca-2,5,8-triene (1) or a mixture of its methyl derivatives was used as termonomer to obtain ethylene—propylene—triene terpolymers (EPTM) having unusual properties in the curing process, even at low levels of triene (ca. 1 wt %). Three types of catalyst systems have been investigated, based on VCl4, VO[O(CH2)3CH3]3, or V(acac)3 and (C2H5)2AlCl. Several parameters of the terpolymerization process were studied (e.g. Al/V mole ratio; catalyst and termonomer concentration; polymerization time; presence of a Lewis base or chain transfer agent) and their influence on Mv and EPTM composition were evaluated. Fractionation data and the use of model compounds allow to conclude that 1 enters EPTM chains randomly and by selective opening of the norbornenic double bond, whereas the conjugated diene system is involved in side reactions if the catalyst has some acid character or the concentration of the triene is above some critical value.

REACTIONS OF THE ETHYL RADICAL: VI. ADDITION TO CONJUGATED DIENES

1965 ◽  
Vol 43 (5) ◽  
pp. 1102-1109 ◽  
Author(s):  
A. C. R. Brown ◽  
D. G. L. James
Keyword(s):  
Rate Constants ◽  
Chain Transfer ◽  
Conjugated Dienes ◽  
Energy Of Activation ◽  
Conjugated Diene ◽  
Kcal Mole ◽  
Hydrogen Atoms ◽  
Ethyl Radical ◽  
Diene System ◽  
Rate Constants For Addition

Arrhenius parameters have been measured for the addition of the ethyl radical to the conjugated diene system in three representative molecular environments. Significant differences are found among the values of the energy of activation for addition, which are: 4.5 ± 0.2 kcal/mole for 2,3-dimethylbutadiene-1,3, 5.2 ± 0.3 kcal/mole for cyclohexadiene-1,3, and 6.6 ± 0.3 kcal/mole for 2,5-dimethylhexadiene-2,4. The increase in the energy of activation in this series is paralleled by an increase in the degree of shielding of the terminal carbon atoms of the conjugated system by substituent groups. The energy of activation for metathesis is significantly lower for cyclohexadiene-1,3 (5.4 ± 0.5 kcal/mole) than for 2,5-dimethylhexadiene-2,4 (7.6 ± 0.4 kcal/mole); the activated hydrogen atoms of the former are all secondary, whereas those of the latter are all primary. The ratio of the rate constants for addition and metathesis at 60° indicate that the radical homopolymerization of cyclohexadiene-1,3 and 2,5-dimethylhexadiene-2,4 should be subject to extensive degradative chain transfer.

Enhancing the Feasibility of Pd/C-catalyzed Formic Acid Decomposition for Hydrogen Generation – Catalyst Pretreatment, Deactivation, and Regeneration

2021 ◽  
Author(s):  
Axel Kosider ◽  
Dominik Blaumeiser ◽  
Simon Schoetz ◽  
Patrick Preuster ◽  
Andreas Bösmann ◽  
...  
Keyword(s):  
Formic Acid ◽  
Low Temperatures ◽  
Hydrogen Generation ◽  
Side Reactions ◽  
Acid Decomposition ◽  
Catalyst Pretreatment ◽  
Formic Acid Decomposition ◽  
Catalyst Systems

Formic acid decomposition (FAD) generates H2 at low temperatures. However, many known catalyst systems suffer from deactivation due to competing side reactions during FAD. In this work, we focus on...

Ethylene-Propylene Copolymers Produced with Soluble Catalysts

1962 ◽  
Vol 35 (4) ◽  
pp. 1101-1113
Author(s):  
R. J. Kelly ◽  
H. K. Garner ◽  
H. E. Haxo ◽  
W. R. Bingham
Keyword(s):  
Physical Properties ◽  
Heterogeneous Catalysts ◽  
Accelerated Aging ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Ethylene Propylene ◽  
Aging Properties ◽  
Aluminum Halide ◽  
Catalyst Systems ◽  
Catalyst Efficiency

Abstract Soluble catalyst systems derived from alkyl aluminum halides in combination with vanadium oxytrichloride or tetrachloride produce highly random ethylene-propylene copolymers with high catalyst efficiency. By the choice of the alkyl aluminum halide and molar ratio of aluminum to vanadium, variations in polymerization efficiency and molecular weight are possible. The copolymers prepared with these soluble catalysts show advantages in both processing and physical properties over those prepared with heterogeneous catalysts. Vulcanizates of these copolymers show somewhat different accelerated aging properties depending on the additive used along with the peroxide. Low temperature properties of copolymers containing less than 70 weight % propylene show a tendency for crystallization which is not shown by X-ray diffraction. Overall physical properties and tire tests show some preference for the 65 weight % propylene copolymer over the 50% material.

THE POLYMERIZATION OF ISOPRENE AND 2, 3-DIMETHYLBUTADIENE AND COPOLYMERIZATION WITH STYRENE AT −18 °C. IN EMULSION

1952 ◽  
Vol 30 (2) ◽  
pp. 108-123 ◽  
Author(s):  
R. J. Orr ◽  
H. Leverne Williams
Keyword(s):  
Transfer Reaction ◽  
Chain Transfer ◽  
Price Equation ◽  
Side Reactions ◽  
Polymerization Temperature ◽  
Reactivity Ratios ◽  
Molecular Weights ◽  
Rate Of Polymerization ◽  
Chain Transfer Reaction ◽  
Cyclic Compounds

The rate of polymerization increased with purification of the monomers. It was possible that the dienes formed cyclic compounds or dimers in side reactions. The 1,2 addition of the monomer decreased with decreasing polymerization temperature. A study was made of the copolymerization of isoprene and dimethylbutadiene with styrene at −18° C. From analyses of bound diene in the product at various conversions and initial diene to styrene ratios the reactivity ratios for these diene-styrene systems were calculated to be r1 = 1.30 ± 0.02 and r2 = 0.48 ± 0.01 for isoprene and styrene and r1 = 0.92 ± 0.02, r2 = 0.42 ± 0.02 for dimethylbutadiene and styrene (styrene always being considered monomer 2). Q and e values from the Alfrey-Price equation were calculated as Q = 119 and e = −0.112 for isoprene and Q = 1.09 and e = −0.181 for dimethylbutadiene relative to Q = 1.0 and e = −0.8 for styrene. Fom these and the values previously determined for butadiene, reactivity ratios for all combinations of the three dienes were calculated. The chain transfer reaction between dienyl radicals and mixed tertiary mercaptans was studied and it was found that isoprenyl and dimethylbutadienyl radicals were much more reactive than butadienyl. The effect of this was illustrated by number and viscosity average molecular weights. Intrinsic viscosities of homo- and copolymers formed in a mercaptan-free recipe were measured and compared.

scholarly journals Mass spectra of lepidopterous sex pheromones with a conjugated diene system.

1988 ◽  
Vol 52 (6) ◽  
pp. 1415-1423 ◽  
Author(s):  
Tetsu ANDO ◽  
Yasushi OGURA ◽  
Masaaki UCHIYAMA
Keyword(s):  
Mass Spectra ◽  
Sex Pheromones ◽  
Conjugated Diene ◽  
Diene System

scholarly journals Lepidopterous sex attractants with a conjugated diene system.

1987 ◽  
Vol 51 (10) ◽  
pp. 2691-2694 ◽  
Author(s):  
Tetsu ANDO ◽  
Mizue KOIKE ◽  
Masaaki UCHIYAMA ◽  
Hiroshi KUROKO
Keyword(s):  
Conjugated Diene ◽  
Sex Attractants ◽  
Diene System

Photodegradation of Ethylene/Propylene/Polar Monomers Co‐ and Terpolymers. I—Prepared by Group 4 Catalyst Systems

2005 ◽  
Vol 42 (9) ◽  
pp. 1259-1270
Author(s):  
Susete Fernandes ◽  
Sandra Correia ◽  
A. Vishwa Prasad ◽  
K. Raghunatha Reddy ◽  
S. Rana ◽  
...  
Keyword(s):  
Ethylene Propylene ◽  
Group 4 ◽  
Polar Monomers ◽  
Catalyst Systems

The compositional inhomogeneity of ethylene-propylene copolymers formed by polymerization with the (C2H5)2AlClVOCl3, and (iso-C4H9)2AlClVOCl3 catalyst systems

1980 ◽  
Vol 22 (8) ◽  
pp. 1841-1848 ◽  
Author(s):  
Ye.G. Brenburg ◽  
I.A. Livshits ◽  
Ye.O. Osipchuk ◽  
Ye.R. Gershtein ◽  
S.P. Yevdokimova ◽  
...  
Keyword(s):  
Ethylene Propylene ◽  
Catalyst Systems
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