Search results
Results From The WOW.Com Content Network
cationic polymerization: An ionic polymerization in which the kinetic-chain carriers are cations. [ 1 ] In polymer chemistry , cationic polymerization is a type of chain growth polymerization in which a cationic initiator transfers charge to a monomer , which then becomes reactive.
Styrene-butane co-polymers include PS-I and SBC (see below), both co-polymers are impact resistant. PS-I is prepared by graft co-polymerization, SBC by anionic block co-polymerization, which makes it transparent in case of appropriate block size. [62] If styrene-butane co-polymer has a high butylene content, styrene-butadiene rubber (SBR) is ...
Twenty years later, living polymerization was demonstrated by Szwarc through the anionic polymerization of styrene in THF using sodium naphthalene as an initiator. [10] [6] [11] The naphthalene anion initiates polymerization by reducing styrene to its radical anion, which dimerizes to the dilithiodiphenylbutane, which then initiates the ...
Living cationic polymerization is a living polymerization technique involving cationic propagating species. [1] [2] It enables the synthesis of very well defined polymers (low molar mass distribution) and of polymers with unusual architecture such as star polymers and block copolymers and living cationic polymerization is therefore as such of commercial and academic interest.
Because, by definition, polymerization reactions only take place in the presence of monomer, chain transfer to monomer determines the theoretical maximum molecular weight that can be achieved by a given monomer. Chain transfer to monomer is especially significant in cationic addition polymerization and ring-opening polymerization.
Living anionic polymerization is a living polymerization technique involving an anionic propagating species. Living anionic polymerization was demonstrated by Szwarc and co workers in 1956. Their initial work was based on the polymerization of styrene and dienes.
In polymer chemistry, ionic polymerization is a chain-growth polymerization in which active centers are ions or ion pairs. [2] It can be considered as an alternative to radical polymerization, and may refer to anionic polymerization or cationic polymerization. [3] As with radical polymerization, reactions are initiated by a reactive compound.
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. [1] [2] [3] There are many forms of polymerization [4] and different systems exist to categorize them. IUPAC definition for ...