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.
It is produced by polymerization of styrene in the presence of polybutadiene dissolved (in styrene). Polymerization takes place simultaneously in two ways: [64] Graft copolymerization: The growing polystyrene chain reacts with a double bond of the polybutadiene. As a result, several polystyrene chains are attached to one polybutadiene.
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.
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 ...
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, chain transfer is a polymerization reaction by which the activity of a growing polymer chain is transferred to another molecule: [1] [2] + + where • is the active center, P is the initial polymer chain, X is the end group, and R is the substituent to which the active center is transferred.
Solution styrene-butadiene rubber (sSBR) is produced by anionic polymerization in hydrocarbons leading to rubber with better properties for making tires than emulsion polymerization type. Polyvinyl acetate used further for polyvinyl alcohol is manufactured by radical polymerization in methanol solution.
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 ...