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Electrostatic interactions can form nanogels through the combination of anionic and cationic polymers in an aqueous solution. [3] The size and surface charge of the resulting nanogels can be modulated by changing the molecular weight or the charge ratio of the two different polymers. [ 3 ]
Other polymers formed by cationic polymerization are homopolymers and copolymers of polyterpenes, such as pinenes (plant-derived products), that are used as tackifiers. In the field of heterocycles, 1,3,5-trioxane is copolymerized with small amounts of ethylene oxide to form the highly crystalline polyoxymethylene plastic.
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.
Nanoparticles range in size from 10 - 1000 nm (or 1 μm) and they can be made from natural or artificial polymers, lipids, dendrimers, and micelles. [ 1 ] [ 5 ] Most polymers used for nanoparticle drug delivery systems are natural, biocompatible , and biodegradable , which helps prevent contamination in the CNS.
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.
Since polymer chains are often in close proximity to other parts of the same chain or to other chains, like-charged parts of the polymer repel each other. This repulsion leads to a swelling of the polymer. [citation needed] Polymers can also form micelles (spheres) in response to a change in pH. This behavior can occur with linear block copolymers.
Polylysine is a homopolypeptide belonging to the group of cationic polymers: at pH 7, polylysine contains a positively charged hydrophilic amino group. Structure of α-polylysine. α-Polylysine is a synthetic polymer, which can be composed of either L-lysine or D-lysine. "L" and "D" refer to the chirality at lysine's central carbon.
In anhydrous form, 2-ethyl-2-oxazoline is mostly used as a monomer. [2]The cationic ring-opening polymerization of 2-ethyl-2-oxazoline [12] can be initiated by alkylation with e.g. methyl tosylate or triflates (in particular methyl triflate) and leads to the water-soluble poly(2-ethyl-2-oxazoline) which is a propionyl-substituted linear polyethylenimine and can also be seen as a pseudo ...