Free radical mechanism for reactive processing of polymers in the presence of organoclay/peroxide nanoreactors: Grafting maleic anhydride onto polypropylene

Autor(es)

Riveros Munoz, Pablo Andres ^[1] ; Canevarolo, Sebastiao Vicente ^[2] ; Prado Bettini, Silvia Helena ^[2]

Afiliação do(s) autor(es)

^[1] Programa Posgrad Ciencias & Engn Mat PPG CEM UFSC, Sao Carlos - Brazil

^[2] Dept Engn Mat DEMa UFSCar, Via Washington Luiz, Km 235, BR-13565905 Sao Carlos - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Chemical Engineering Science; v. 230, FEB 2 2021.
• Citações Web of Science: 0

Resumo

PP-graft-MA is a common PP compatibilizer, produced via reactive extrusion using peroxides as initiator, which causes severe molar mass reduction. To control PP degradation and increase maleic anhydride grafting, Shi and coworkers (2006), proposed the use of nanoreactors. In this paper we propose a complete new reactive mechanism involving nanoreactors during PP-graft-MA reactive processing. The samples were prepared via melt mixing using nanoreactors with different organoclay: peroxide ratios (oMMT:DCP). Organic MMT showed to absorb not more than 16 wt% of DCP, i.e., diffusional controlled release of alkoxy radical will not be observed at o-MMT:DCP ratios < 5:1. The presence of o-MMT tend to increase MA homopolymerization, which consumes the initiator, interfering with the grafting of succinic groups onto the PP backbone, due to increased hindrance of oligo (MA) formed, thereby reducing degradation of the PP chain. Thus, the use of nanoreactors promotes MA homopolymerization rather than grafting as previously proposed in the literature. (C) 2020 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 08/04334-2 - Graftização de anidrido maleico em polipropileno, por processamento reativo, na presença de nanopartículas
• Beneficiário: Silvia Helena Prado Bettini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/21313-1 - Estudo da cinética de reação e da adição de desativadores de metais na graftização de anidrido maleico em polipropileno, na presença e ausência de nanopartículas
• Beneficiário: Silvia Helena Prado Bettini
• Modalidade de apoio: Auxílio à Pesquisa - Regular