Banca de QUALIFICAÇÃO: CARLOS HENRIQUE RODRIGUES MILFONT

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : CARLOS HENRIQUE RODRIGUES MILFONT
DATE: 28/11/2024
TIME: 13:00
LOCAL: Hibrido
TITLE:

STUDY OF THE INTERACTION BETWEEN DIFFERENT STARCHES IN THE DEVELOPMENT OF THERMOPLASTIC STARCH

KEY WORDS:

starch, thermoplastic starch, casting, extrusion, optimization

PAGES: 163
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Polímeros, Aplicações
SUMMARY:

This study aimed to evaluate the influence of the interaction of starches from different botanical origins on the optical, physical, chemical, thermal, and mechanical properties of thermoplastic starches (TPS). A simplex-centroid mixture design {3,2} was used with three components: corn starch (Mi), cassava starch (Ma), and potato starch (Ba). The TPS were obtained through casting and extrusion techniques. Preliminary characterizations indicated that the starch granules from corn, cassava, and potato had amylose contents of 29.52%, 18.19%, and 34.77%, respectively. Rheological results from starch solutions in parallel plates showed that corn starch had the highest values for apparent viscosity and thixotropy, while the starch mixtures displayed intermediate values of G' (elastic modulus), G'' (viscous modulus), and |η*| (complex viscosity) compared to their pure components. In films obtained by casting, the interaction between starch types influenced opacity and crystallinity, with higher opacity and crystallinity observed in films containing a greater proportion of potato starch. The ternary mixtures Mi/Ma/Ba with higher proportions of Mi and Ba showed the lowest percentage values for water solubility. Thermal analysis results indicated that mixtures with a higher proportion of cassava starch tend to be more thermally stable. Mechanical characterization results of the films indicated that the starch mixtures exhibited synergism in increasing the maximum tensile strength of the films. In extruded TPS, increasing the proportion of cassava starch resulted in materials with smoother and shinier surfaces, but with greater susceptibility to moisture. Thermal analysis and mechanical testing results for the extrudates indicated that the materials exhibited intermediate thermal and mechanical properties compared to their pure components. Overall, the results indicated a considerable influence of amylose content, molecular weight of the starches, and the TPS production technique on the interaction between the starches. The contour surfaces obtained for the material properties showed that mixing different starches could be an interesting solution for producing TPS with optimized properties.

COMMITTEE MEMBERS:
Presidente - 1639676 - EDSON NORIYUKI ITO
Externo à Instituição - ADRIANO LINCOLN ALBUQUERQUE MATTOS - EMBRAPA
Externa à Instituição - JUCIKLÉCIA DA SILVA REINALDO - UEA
Externo à Instituição - MEN DE SÁ MOREIRA DE SOUZA FILHO - EMBRAPA