Effect of heterophasic or random PP copolymer on the compatibility mechanism between EVA and PP copolymers

• Published in: Journal of applied polymer science Vol. 112; no. 4; pp. 2290 - 2297
• Main Authors: Ramírez-Vargas, Eduardo, Margarita Huerta-Martínez, Blanca, Javier Medellín-Rodríguez, Francisco, Sánchez-Valdes, Saúl
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.05.2009; Wiley
• Subjects: Applied sciences; blends; compatibility; Exact sciences and technology; Mechanical properties; Organic polymers; Physicochemistry of polymers; PP-EP/EVA; Properties and characterization; Structure, morphology and analysis; Propylene copolymer; Polymer blends; Olefin copolymer; Property composition relationship; Mechanical properties; Tensile property; Experimental study; PP-EP/EVA; Heterogeneous mixture; Structure composition relationship; Thermal properties; Random copolymer; EVA; Impact strength; Morphology; Ethylene copolymer; compatibility; blends
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.29827

Compatibility mechanisms between EVA and PP copolymers (C-PP) blends have been studied as a function of the type of copolymer, using a heterophasic PP copolymer (PP-EP) and a random PP copolymer (PP-r-EP), with similar ethylene content. The morphology and thermal and mechanical properties of PP/EVA blends with different levels of EVA containing 28% vinyl acetate (VA) were determined. The obtained results indicated compatibility for both systems showing interactions at the amorphous interfaces; however, this interaction was higher for the PP-r-EP/EVA, which showed a single glass transition temperature and changes in the PP crystalline fraction (changes in the fusion temperature and in the diffraction patterns). The evolution of the morphology from isolated spherical domains (20% EVA) to elongated shapes (40% EVA) was related to the observed changes in thermal and mechanical properties. The impact strength and deformation properties showed significant improvement with increasing EVA content above 40% where the highest values of elongation for the PP-r-EPand of impact strength for the PP-EP were obtained.