The gel of poly(vinyl alcohol) polymer with boric acid, added as a crosslinking agent, was made with a mixture of dimethyl sulfoxide and water. The thermal and dynamic modulus properties of poly(vinyl alcohol) gel were measured by a differential scanning calorimeter and a dynamic mechanical thermoan
Surface grafting of a poly(organophosphazene) onto poly(vinyl alcohol) and poly(ethylene-co-vinyl alcohol) using triethoxysilane as a coupling agent
โ Scribed by Lydie Pemberton; Roger De Jaeger; L. Gengembre
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 209 KB
- Volume
- 69
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
โฆ Synopsis
Triethoxysilane HSi(OEt) 3 was used as coupling agent to graft a poly(organophosphazene) (POPZ) containing allylic functions to the surface of poly(vinyl alcohol) or poly(ethylene-co-vinyl alcohol) films. Hydrolyzed HSi(OEt) 3 , which contained both inorganic (Si-OH) and organic (Si-H) reactivities, acted at the interface between the hydroxylated substrates (via a condensation reaction) and the allylic functions in POPZ (via a hydrosilylation reaction). Starting materials and grafting surfaces were studied by ATR-IR and XPS spectroscopies and contact angle measurements. Data obtained indicated that different POPZ layers were produced, depending on whether the functionalization of materials with silane, and the grafting reaction were separately or simultaneously made. The POPZ layer thickness was higher when the grafting reaction was preceded by the POPZ functionalization. In each cases, the modified surfaces showed marked increases in hydrophobicity character.
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Poly(vinyl alcohol) (PVA) is a well-known biomedical polymer and is biocompatible. Methylmethacrylate and acrylic acid monomers were grafted onto PVA using a Ce(IV)-glucose redox system at three different temperatures (35, 45, and 55ยฐC) under nitrogen atmosphere. More than 80% grafting could be achi