Phase transitions in biodegradable films based on blends of gelatin and poly (vinyl alcohol)


Autoria(s): Sobral,Paulo José do Amaral; Carvalho,Rosemary Aparecida de; Moraes,Izabel Cristina Freitas; Bittante,Ana Mônica Quinta Barbosa; Monterrey-Quintero,Ednelí Soraya
Data(s)

01/06/2011

Resumo

The aim of this work was to study the effect of the hydrolysis degree (HD) and the concentration (C PVA) of two types of poly (vinyl alcohol) (PVA) and the effect of the type and the concentration of plasticizers on the phase properties of biodegradable films based on blends of gelatin and PVA, using a response-surface methodology. The films were made by casting and the studied properties were their glass (Tg) and melting (Tm) transition temperatures, which were determined by diferential scanning calorimetry (DSC). For the data obtained on the first scan, the fitting of the linear model was statistically significant and predictive only for the second melting temperature. In this case, the most important effect on the second Tm of the first scan was due to the HD of the PVA. In relation to the second scan, the linear model could be fit to Tg data with only two statistically significant parameters. Both the PVA and plasticizer concentrations had an important effect on Tg. Concerning the second Tm of the second scan, the linear model was fit to data with two statistically significant parameters, namely the HD and the plasticizer concentration. But, the most important effect was provoked by the HD of the PVA.

Formato

text/html

Identificador

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612011000200015

Idioma(s)

en

Publicador

Sociedade Brasileira de Ciência e Tecnologia de Alimentos

Fonte

Food Science and Technology (Campinas) v.31 n.2 2011

Palavras-Chave #protein #glass transition #melting #surface-response
Tipo

journal article