Molecular characterization of maleic anhydride‐functionalized polypropylene

Abstract

S.A. Direction Centrale des Recherches, Laboratoire Central, 31 0 rue de Ransbeek, B-1 120 Bruxelles, Belgium SYNOPSIS This work deals with the molecular characterization of maleic anhydride melt-functionalized polypropylene ( PP-g-MA). The functionalization mechanism, the nature, the concentration, and the location of grafted anhydride species onto the polypropylene chain are discussed. The polypropylene functionalization was performed using a pre-heated Brabender Plastograph ( 190°C, 4 min of mixing time). Several concentrations of maleic anhydride and organic peroxide were used for this study. In those experimental conditions, the organic peroxide undergoes an homolytic rupture and carries out a polypropylene tertiary hydrogen abstraction. The resulting macroradical undergoes a 0-scission leading to a radical chain end which reacts with maleic anhydride. When a termination reaction occurs at this first step a succinic type anhydride chain end is obtained. However, oligomerization of maleic anhydride is found to occur more frequently leading to poly( maleic anhydride) chain end. Concentration of both anhydride types and minimal length of the grafted poly (maleic anhydride) were determined. A fraction of maleic anhydride does not react with polypropylene or homopolymerize leading to nongrafted poly (maleic anhydride). 0 1995 John Wiley & Sons, Inc.

Funcionalização do Polipropileno com Viniltrietoxisilano em Solução e no Estado Fundido

“…Em geral, as reações são feitas utilizando-se peróxidos, que geram radicais livres na cadeia polimérica, aos quais se adicionam moléculas polares [14] , tais como: fumarato de dietila [5] , anidrido maleico [9,15] , acetato de vinila [16] , ácido acrílico [17,18] , maleato de dietila [19,20] , anidrido itacônico [21] e isocianatos [22] . As primeiras etapas do mecanismo de incorporação de monômeros vinílicos ao PP são normalmente descritas na literatura como segue [23] : A quebra homolítica de cada molécula de peróxido orgânico produz dois radicais (Esquema 1), sendo que a velocidade de decomposição do peróxido depende somente da temperatura. Os radicais formados abstraem um átomo de hidrogênio da cadeia polimérica, produzindo macro-radicais.…”

Chemical Modification of Polypropylene by Maleic Anhydride: Melt Grafting, Characterization and Mechanism

“…As seen in this figure the FT-IR spectrum of PP-g-MA shows the absorption band at (1700-1740cm -1 ) that is due to the presence of DCP and absorption bands at (1760-1800cm -1 ) and around 1850cm -1 can be assigned to grafted anhydride because an intense absorption band near 1785cm -1 and a weak absorption band near 1850cm -1 is due to symmetric and asymmetric C=O stretching respectively. [8], [14], [15]. It has been shown that the intensity of peaks increased by increasing the DCP content from 1 to 4 phr that lead to increase the graft percentage but it decreased by more adding of DCP (6phr) that may be due to decomposition effect of initiator.…”

“…In fact, these kinds of grafted polymers have been widely used to improve interfacial adhesion between the components in polymer blends [2]- [7]. Maleic anhydride has been used recently for the functionalization of polyolefins due to the higher reactivity of the anhydride group toward successive reactions [8]- [10].…”

Preparation and Properties of Polyolefin Graft Polymer available as a Primer for Polyurethane Adhesive (I) Synthesis of polyolefins with cyclic acid anhydride by free radical graft polymerization

“…[12][13][14] Free radical grafting of maleic anhydride (MA) onto polyolefins has gained wide industrial application. [15][16][17] MA modified polyolefins are an essential part of many plastics formulations. They are used as chemical coupling agents, impact modifiers, and compatibilisers for blends and filler reinforced systems.…”