Banca de DEFESA: DJALMA ALVES DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DJALMA ALVES DE OLIVEIRA
DATE: 26/07/2023
TIME: 08:30
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

THERMAL RESPONSIVE BLENDS FORMED BY POLY(N-VINYLCAPROLACTAM) AND POLYURETHANE

KEY WORDS:

Poly(N-vinylcaprolactam); TPU/PNVCL blends; Thermoplastic Polyurethane; thermoresponsive polymers; Miscible and thermoresponsive blends.

PAGES: 70
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Smart polymeric materials capable of responding to external stimuli have great potential for application in the industrial or biomedical area as sensors, electronic devices, packaging, dressings, systems for controlled drug release, support for cell growth, among others. Poly(N- vinylcaprolactam), PNVCL, is a thermoresponsive polymer, whose change from hydrophilic to hydrophobic behavior occurs by changing the temperature, and shows promise due to its non-toxicity, biocompatibility and for having a phase transition temperature of hydrophilic to hydrophobic close to physiological temperature. However, the production of finished products with PNVCL is difficult due to its high mechanical fragility. The improvement of PNVCL properties can be achieved through physical mixing with other polymers, making a polymer blend. In addition, mixing with other polymers also allows changing the phase transition temperatures of PNVCL, which can broaden its application spectrum. In the present work, thermoresponsive plastic films produced by molding in solution from polymeric blends containing different mass proportions of PNVCL and thermoplastic polyurethane (TPU) in the proportions 90/10 70/30 and 50/50, respectively, were made. The films were resistant, flexible and with varied thermal responsiveness depending on the formulated composition. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy by attenuated total reflection (FTIRATR), thermogravimetry (TGA) and differential scanning calorimetry (DSC) analysis confirmed the miscibility of the blends formed and the angle analysis contact test showed that the films present thermal response. It was possible to induce a change in solid films from transparent to opaque by varying the temperature and verify the reversibility of this change. In addition, mechanical tests of traction/deformation were carried out, which proved the mechanical improvement of the PNVCL blends when incorporating TPU. The material developed in this work is innovative and has potential for application in many areas.

COMMITTEE MEMBERS:
Externo à Instituição - JULIANO MARINI - UFSCAR
Presidente - 1356402 - CAROLINA LIPPARELLI MORELLI
Interno - 1354207 - SEVERINO ALVES JUNIOR