The effect of a p‐phenylen‐bis‐maleamic acid grafted atactic polypropylene interfacial agent on the dynamic‐mechanical properties of iPP/Mica composites measured at the polymer transitions

Abstract

This work deals with the study of the evolution (with temperature) of the in‐phase (E′) and the out‐of‐phase (E″) moduli of polypropylene/mica composites with improved interfacial interactions by the presence of an industrial waste based interfacial modifier named as p‐phenylen‐bis‐maleamic (pPBMA) acid grafted atactic polypropylene (aPP–pPBMA). This additive contains 15% w/w grafted pPBMA (5.0·10−4 g mol−1) obtained from polymer industrial wastes in the Polymer Engineering Group (GIP) labs. The purpose of the work is twofold. One, dynamic mechanical analysis (DMA) has been used to evidence the improvement in properties due to the interfacial modifications by the addition of the novel interfacial modifier (aPP–pPBMA). And two, to obtain a mathematical model to predict the DMA moduli of the composite at α and β transition temperatures. So, a Box–Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables, and the modulus as the dependent ones at each transition was used. Thus, the final purpose of the work is obtaining forecasts for the DMA parameters as a function of the composite components and of the type of temperature dependent relaxation phenomena taking place. POLYM. ENG. SCI., 57:746–755, 2017. © 2017 Society of Plastics Engineers

The Variance of the Polypropylene α Relaxation Temperature in iPP/a-PP-pPBMA/Mica Composites

“…This aspect was confirmed by SIRM (Synchrotron Infra-Red Microscopy) spectroscopy [3,4,12,23]. Furthermore, the existence of the same critical point in terms of the component amount in the composite was found independently of the characterization method used (tensile, flexural, impact, DSC, TGA, SEM, FESEM, and so on) [3,4,8,[23][24][25].…”

“…The definition of nano-composite by the International Union of Pure and Applied Chemistry (IUPAC) implies considering that one (or both) phase domains in the material are in the nano-metric scale at least in one dimension [7]. This definition agrees with the iPP/mica composites, with mica exhibiting one dimension (thickness) in the nano-scale order close to 30 nm, even if non-exfoliated [3,8].…”

“…Moreover, very often, a small amount of this additive is not only enough, but mandatory to optimize the properties of the iPP-based composite as a whole. The interfacial agent used in this work was obtained by the authors from polymer wastes by grafting a novel functionality (p-phenylen-bis maleamic acid) to the polymer backbone instead of the usual maleic anhydride grafts, which imply several shortcomings for green chemistry and eco-friendly framework [8,15]. This type of organic-inorganic composite is a multi-component compound exhibiting at least one of the components (the polymers and/or the reinforcement) in the submicrometric or better in the nano-metric size domain [16,17].…”

“…As a result, the interphase between components becomes weak. Despite the vast amount of investigation conducted on the interfacial interactions, it is a fact that the precise interpretation of such complex phenomena is still open [3,8,9,[11][12][13][14][15][16][17]22]. One of the most efficient strategies to improve the composite properties is by using additives (the so-called inter-facial agents).…”

“…The study of these complex systems requires experimental designs able to detect the critical points of the system. Perhaps it is well worth noting what a complex system represents, which is one consisting of many blocks able to exchange stimuli between them and the surroundings depending on the contour conditions [3,4,8,28,29]. Therefore, a route to model this type of system is using "agent-based models" [28,29].…”