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That is, the polymer is unstable in a water based environment. This is the prevailing mechanism for the polymers degradation. This occurs in two stages. 1. Water penetrates the bulk of the device, attacking the chemical bonds in the amorphous phase and converting long polymer chains into shorter water-soluble fragments.
Fluorinated polymers like PTFE and PVDF are especially thermally stable due to strong carbon-fluorine (C–F) bonds, the strongest in organic chemistry, which contribute to the durability of these materials under heat. PVDF is semi-crystalline, giving it a balance of rigidity and flexibility across temperatures from −35 °C to 160 °C.
This material can be used for biodegradable, homogeneous, dense films that are very useful in the biomedical field. Alginate: Alginate is the most copious marine natural polymer derived from brown seaweed. Alginate biopolymer applications range from packaging, textile and food industry to biomedical and chemical engineering.
Polyphosphazenes include a wide range of hybrid inorganic-organic polymers with a number of different skeletal architectures with the backbone P-N-P-N-P-N-. [1] In nearly all of these materials two organic side groups are attached to each phosphorus center. Linear polymers have the formula (N=PR 1 R 2) n, where R 1 and R 2 are organic
The polymer is dissolved in an organic solvent (such as dichloromethane). Powdered drug and filler (typically an inert sugar) are added to the liquid solution and rapidly mixed to obtain a homogeneous mixture. The drug-filler-polymer mixture is then cast into a mold at −80 °C and freeze-dried until solid.
Polyvinylpyrrolidone (PVP), also commonly called polyvidone or povidone, is a water-soluble polymer compound made from the monomer N-vinylpyrrolidone. [1] PVP is available in a range of molecular weights and related viscosities, and can be selected according to the desired application properties.
Vinyl polymers are subject of several structural variations, which greatly expands the range of polymers and their applications. With the exception of polyethylene, vinyl polymers can arise from head-to-tail linking of monomers, head-to-head combined with tail-to-tail, or a mixture of those two patterns. Additionally the substituted carbon center in such polymers is stereogenic (a "chiral center")
Pages in category "Vinyl polymers" The following 26 pages are in this category, out of 26 total. This list may not reflect recent changes. ...