| Texto completo | |
| Autor(es): |
Roberta Ranielle Matos de Freitas
;
Karina Palmizani do Carmo
;
Franciane Andrade de Pádua
[3]
;
Vagner Roberto Botaro
Número total de Autores: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 28, 2025-03-03. |
| Resumo | |
This study investigated the kinetics and thermodynamics of starch acetylation and examined the influence of the degree of substitution (DS) on the properties of acetylated starches. Starch acetylation kinetics followed a pseudo-first-order model, reaching a degree of substitution of 2.62 after 50 minutes. Negative enthalpy and entropy values revealed a non-spontaneous reaction requiring catalysis. Fourier Transform Infrared Spectroscopy confirmed acetylation through the appearance of a carbonyl band and the reduction of the glycosidic bond peak. Increasing degree of substitution caused granule breakage, agglutination, and reduced crystallinity, as evidenced by Scanning Electron Microscopy and X-Ray Diffraction. Dynamic Mechanical Analysis demonstrated that these structural changes reduced the glass transition in high degrees of substitution (DS 2.62) and enhanced thermal stability and viscoelastic properties due to the loss of crystallinity. Understanding these processes facilitates the industrial optimization of starch acetylation, resulting in modified starches with improved properties for diverse applications. (AU) | |
| Processo FAPESP: | 16/19896-2 - Estudo do comportamento térmico dinâmico-mecânico de filmes poliméricos de hidrogéis visando a aplicação como futuros materiais biocompatíveis |
| Beneficiário: | Vagner Roberto Botaro |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |