Thermal, mechanical, and water vapor barrier behavior of polypropylene composite containing modified kaolinite

• Published in: Journal of applied polymer science Vol. 135; no. 5
• Main Authors: Albach, Breidi, Munaro, Marilda, Santos, Pedro H., Zawadzki, Sônia F., Schreiner, Wido H., Rampon, Daniel S., Barbosa, Ronilson V.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 05-02-2018
• Subjects: Compatibility; compatibilization; Coupling agents; extrusion; Fourier transforms; Heat measurement; Kaolinite; Materials science; Modulus of elasticity; Polymer matrix composites; Polymers; Polypropylene; spectroscopy; Spectrum analysis; Stability analysis; thermal properties; Thermal stability; Thermogravimetric analysis; Water vapor; X ray photoelectron spectroscopy; X-ray diffraction; X-rays; X‐ray
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.45785

ABSTRACT
Polypropylene composites containing modified kaolinite were prepared using melt processing and the morphological, thermal, mechanical and their water barrier properties were analyzed. To improve compatibility with polypropylene, kaolinite was modified with silane as a coupling agent. Characterization techniques (X‐ray diffraction, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy) confirmed the effective grafting of these compounds on the surface and edges of the kaolinite with no functionalization on the inner surface. The differential scanning calorimetry and X‐ray diffraction techniques demonstrated that the addition of grafted kaolinite affected the iPP crystallinity. The thermogravimetric analysis helped to determine the thermal stability of the composites, being this, dependent on the amount of kaolinite and silane. The stress–strain tests demonstrated an increase in Young's modulus and obtained a 70% reduction in water vapor permeation. These improvements were mainly related to the increased compatibility between the iPP/Kaol interfaces promoted by the silane. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45785.