The effect of montmorillonite and compatibilizer quantities on stiffness and toughness of polyamide nanoblends

Abstract

Although polymer blend nanocomposites are widely studied, the balance between stiffness and toughness has not yet been investigated in detail. Some materials producers as well as some sectors in the automotive industry try to improve the toughness of materials without an important loss in stiffness. With this in mind, the aim of the study reported here was to obtain a good balance between toughness and stiffness of polymer blends with different amounts of clay and compatibilizer. In this context, the microstructure of polyamide 6/ethylene–propylene–diene metallocene terpolymer/(ethylene–propylene–diene copolymer)‐graft‐(maleic anhydride) blends with various amounts of clay (2, 3, 4 and 5 wt%) and compatibilizer (10 and 20 wt%) was studied to analyse the achieved morphology to understand the macroscopic properties. The morphology of the rubber phase and the dispersion of the montmorillonite (MMT) are the main factors that influence the mechanical properties. In this sense, the highest Young's modulus is achieved for nanoblends with 5 wt% of MMT, although this nanoblend has the lowest value of notched Izod impact strength. The results obtained suggest that there is a clear trade‐off between stiffness, toughness and temperature behaviour when the ratio of (ethylene–propylene–diene copolymer)‐graft‐(maleic anhydride) to MMT is 5:1. Copyright © 2009 Society of Chemical Industry

Influência da modificação da argila montmorilonita nas propriedades mecânicas, termo-mecânicas e morfológicas de nanocompósitos de blendas de poliamida 6/Acrilonitrila-EPDM-estireno

“…No entanto, estes polímeros tornam-se frágeis na presença de concentradores de tensão, tais como, um entalhe. Isto é, estes materiais são dúcteis quando não entalhados, mas fraturam de maneira frágil quando entalhados, devido a sua baixa resistência à propagação da trinca [8][9][10] . Para melhorar seu desempenho tem se utilizado a técnica de tenacificação da poliamida com materiais elastoméricos [11][12][13][14][15] .…”

“…Estudos com nanocompósitos de poliamida 6 tenacificada com borracha têm mostrado que quando a nanoargila está localizada na fase matriz ocorre uma redução do tamanho dos domínios da fase dispersa [3,4,8,16] . Isto muitas vezes foi atribuído ao efeito da nanoargila de prevenir a coalescência dos domínios dispersos e/ou a um efeito compatibilizante apresentado pela nanocarga localizada na interface entre os dois polímeros imiscíveis.…”

PMMA/SAN and SAN/PBT nanoblends obtained by blending extrusion using thermodynamics and microrheology basis

“…Usually those polymer blends are referred to as nanoblends [1]. Although, the same terminology can be found in the literature to describe mixture of inorganic nanoparticles with polymer, which should mostly be referred as nanocomposites [2]. Nanoblends have been developed to be applied in electronic, membrane, sensing probes and optical applications [3][4][5].…”

“…In addition, sometimes compatibilization is necessary to reduce the interfacial tension and to prevent the coalescence for higher disperse phase content in the polymer blend [21]. One of main rheological parameters is the viscosity ratio between the liquids, which can be determined by Equation (2) [22]: (2) where $ d and $ m are the viscosity values for the disperse and matrix phase at the mixing temperature, respectively. For simple shear flow at small Newtonian liquid deformations, the particle diameter D, due the drop breakup, can be determined by balancing interfacial tension (!)…”

The role of organic modification of layered nanosilicates on mechanical and surface properties of organic–inorganic coatings

“…[1][2][3][4] These organic-inorganic (O-I) nanocomposites contained only a few wt% of clay admixtures but showed significantly improved physical and mechanical properties in comparison with the corresponding pure nylon polymer. Since then, a number of O-I nanocomposites made from layered silicates and from various polymeric matrices, e.g., polyamide (PA) and PA blends, [5][6][7][8][9] polyolefins and their copolymers and blends, [10][11][12][13][14] rubber and derivates, 15,16 polyvinylchloride, 17 polyurethane, 18 epoxide, 19 polyaniline, 20 etc. (see also reviews 21,22 ) have been studied all over the world.…”