The membrane-forming process and the cross-linking reactions consisted of the addition reaction
between the silicon-hydrogen bond and the vinyl group can carry out together at room temperature.
Abstract Michael addition reactions
were utilized to form A[B.
This was already observed in the results section and it was explained by the decrease in residual unsaturation upon increasing the peroxide level, due to enhanced addition reactions
, and the subsequent decreased susceptibility for further crosslinking during aging.
Alkenes in general are known to undergo addition reactions
at lower temperatures and allylic substitution at higher temperatures.
13]C NMR and 13C NMR characterization of the linear polymer prepared by the polymerization of the model compound N-phenylmaleimide with BTA further supported the coexistence of the Michael addition reaction
and free radical polymerization mechanisms.
Of course, the desired reaction pathway for a polymer radical (Po) is crosslink formation either through coupling with another polymer radical or addition reactions
through in-chain or pendant double bonds (unsaturated elastomers).
This issue covers reactions of aldehydes and ketones and their derivatives; reactions of carboxylic, phosphoric and sulfonic acids and their derivatives; oxidation and reduction; carbenes and nitrenes; nucleophilic and electrophilic aromatic substitution; carbocations; nucleophilic aliphatic substitution; carbanions and electrophilic aliphatic substitution; elimination reaction; addition reactions
(polar addition and cycloaddition); and molecular rearrangements.
The R groups attached to the carbodiimide functionality determine selectively what type of addition reactions
occur and under what kinetically driven conditions.
The kinetic model simulation has to be able to either describe the complete cross-linking process phenomenologically (4) or mechanistically (5-7) including homolytic cleavage of the peroxide, beta cleavage of the oxy radical, hydrogen abstraction, addition reactions
, radical coupling (cross-link formation), polymer scission, and radical transfer for a wide range of compositions and an assortment of elastomers, using a single set of rate constants.
The general shortcoming of this type of kinetic models is the inability lo distinguish among several possible cross-linking reaction sites such as hydrogen aroms bonded to aliphatic carbon atom and double bonds, which are subjected lo hydrogen abstraction and addition reactions
The grafting of acrylic acid to the co-oligomer succeeded by radical addition reactions
between the double bonds of BuAA and acrylic acid, and also by addition reactions
between the acrylic rests.
A mechanism of reaction is proposed with the formation of crosslinked structures involving free-radical double bond addition reactions
The Formation of Carbon-Sulfur and Carbon-Selenium Bonds by Substitution and Addition Reactions
Catalyzed by Transition Metal Complexes
INTERMOLECULAR ADDITION REACTIONS
ONTO C-C MULTIPLE BONDS
1,3-dipolar cycloaddition and other addition reactions
of nitrile oxides.