| Journal: | Materials research |
| Database: | PERIÓDICA |
| System number: | 000312977 |
| ISSN: | 1516-1439 |
| Authors: | Paranhos, Caio Marcio1 Oliveira, Renata Nunes Soares, Bluma Guenther Pessan, Luiz Antonio2 |
| Institutions: | 1Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Rio de Janeiro. Brasil 2Universidade Federal de Sao Carlos, Departamento de Engenharia de Materiais, Sao Carlos, Sao Paulo. Brasil |
| Year: | 2007 |
| Season: | Ene-Mar |
| Volumen: | 10 |
| Number: | 1 |
| Pages: | 43-46 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Nota breve o noticia |
| Approach: | Experimental |
| English abstract | Poly(vinyl alcohol) (PVA) hydrogels were obtained by freezing (-22 °C) and thawing (+25 °C) process, resulting in a semi-interpenetrating polymer network (s-IPN) with a sulfonated polyester (PES). The cryo-gels samples were analysed in terms of its water uptake capacity (WU) as a function of pH, temperature and ionic strength. WU of all samples were relatively high, and they showed a reasonable sensitivity to both pH and ionic strength. The pH- and ionic strength dependence is attributed to the dissociation of ionizable groups of PES. The degrees of crystallinity of the cryo-gels, determined by using differential scanning calorimetry (DSC), are lower than pure PVA. Besides, decrease of glass transition temperature (Tg) of the samples when compared with pure PVA was observed. This results are due interactions between PVA and PES, which lead to an increase on the amorphous content of the hydrogels. Our results show that, despite of changes in the microstructure of the hydrogels due the presence of the polyelectrolyte, the cryo-gels reveal a long-term stability |
| Disciplines: | Ingeniería, Química |
| Keyword: | Ingeniería de materiales, Química de polímeros, Hidrogeles, Alcohol polivinílico, Fuerza iónica, Temperatura, Microestructuras |
| Keyword: | Engineering, Chemistry, Materials engineering, Polymer chemistry, Hydrogels, Polyvinyl alcohol, Ionic strength, Temperature, Microstructures |
| Full text: | Texto completo (Ver HTML) |
