Observations on the homogeneity of crosslinked copolymers prepared by γ-irradiation

“…Crosslinked PNVP has the potential to be use as vitreous substitute (61). Because of its hydrophility, NVP is copolymerized with hydrophobic comonomers to improve the mechanical strength (62)(63)(64). NVP copolymerized with methyl methacrylate (MMA) using 1,1,1-trimethylol propane trimethacrylate (TPTA) as cross-linker, is highly permeable and transparent (65).…”

Section: Poly(n-vinyl 2-pyrrolidone) Hydrogels Hydrogel Based On Nvpmentioning

confidence: 99%

Hydrogels

Cai¹,

Gupta²,

Staff³

2012

Kirk-Othmer Encyclopedia of Chemical Technology

View full text Add to dashboard Cite

Hydrogels are hydrophilic polymer networks that are able to swell and retain large amounts of water and maintain three‐dimensional swollen structures. These hydrogels do not dissolve in water. Common monomers and polymerization methods are discussed as well as synthesis and mechanism of biodegradable hydrogels. Responsive hydrogels can reversibly change volume in response to slight changes in the properties of the medium including pH, temperature, electric field, ionic strength, salt type, solvent, external stress or light. Microgels are cross‐linked microparticles that are swollen by a good solvent and have globular structure. Due to their compact structure the intrinsic viscosities of these microgels are much lower than those of the corresponding liner or branched polymers. Hydrogels are used in molecular separation based on size exclusion, protein isolation by conjugating, in drug delivery, as artificial organs, in tissue engineering, in wound dressings, as fire protection, as superabsorbent material in diapers, water sealing, agricultural applications, and in cosmetics products. For cosmetics, hydrogels provide emulsion stability and conditioning, and therapeutics agents can be added to the hydrogel.

show abstract

“…If the polymerization is carried out incorrectly, significant amounts of uncross-linked soluble polymer may be present that must be removed before a meaningful physical analysis such as swell ratio can be accomplished. The solution to this problem is to balance the reactivity ratios of the cross-linker and other comonomers with those of VP to obtain uniform copolymerization and cross-linking (60,61). Not only does this reduce the level of soluble uncross-linked polymer but affords crystal-clear hydrogels so important for use in contact lenses.…”

Section: Pvp Hydrogelsmentioning

confidence: 99%

N‐Vinylamide Polymers

2000

Kirk-Othmer Encyclopedia of Chemical Technology

View full text Add to dashboard Cite

N ‐Vinyl lactams and their corresponding polymers and copolymers have received considerable attention in the academic literature and significant commercial success. However, until recently this interest centered on N ‐vinyl pyrrolidinone and its polymers and copolymers. N ‐Vinyl caprolactam is now emerging commercially because copolymerization with N ‐vinyl pyrrolidinone results in copolymers with high levels of lactam functionality but with controlled hydrophobicity desired in many hair‐fixative products designed to resist drop in high humidity environments. Polyvinylpyrrolidinone (PVP) is a unique water‐soluble polymer that forms lustrous, continuous films on dry‐down that are very adhesive because of hydrogen‐bonding to substrates such as skin and hair. This adhesive characteristic also results in a wide variety of useful applications such as pharmaceutical tablet binding, hot‐melt, and paper adhesive applications. PVP is relatively nontoxic and contributes mildness to formulations. PVP will also complex with a variety of small and large molecules because the pyrrolidinone carbonyl group can accept a proton in the presence of large anions, becoming pseudocationic. In addition, because of lactam polarity where significant charge can appear on the nitrogen and oxygen atoms, it can interact with electron‐rich aromatics. Ligands such as anionic dyes and surfactants or triiodide or phenolic or polynuclear aromatics or polyacids, etc, will interact and complex with PVP. PVPHI 3 or povidone‐iodine is probably the most successful of these complexes, retaining a reservoir of iodine even in dilute solution, affording fresh germicidal iodine as free iodine is consumed. Cross‐linked PVP or crospovidone can be employed to remove bitter tannins (phenolics) from beer and wine. Dry crospovidone can be compressed because of interhydrogen‐bonding, only to rapidly swell when exposed to moisture. For this reason it has achieved success as a tablet disintegrant.

show abstract

Observations on the homogeneity of crosslinked copolymers prepared by γ-irradiation

Cited by 24 publications

References 8 publications

Effect of γ-dose rate and total dose interrelation on the polymeric hydrogel: A novel injectable male contraceptive

Effect of γ-dose rate and total dose interrelation on the polymeric hydrogel: A novel injectable male contraceptive

Hydrogels

N‐Vinylamide Polymers

Contact Info

Product

Resources

About