Structure Analysis of PVC Nanocomposites

Abstract

In this paper poly(vinyl chloride)/clay nanocomposites were prepared by melt intercalation using a single screw extruder. Problems with thermal stability of these nanocomposites during compounding were largely eliminated by pre‐treatment of the organoclay with plasticizer (dioctyl phthalate), which created a barrier between polymer and quaternary amine. These nanocomposite materials were analyzed with respect to their morphology. The intercalation, exfoliation, nano‐phase dispersion and orientation were investigated using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X‐ray diffraction (XRD). Moreover, different types of sample preparation for these techniques were tested as well. It was found that partially intercalated and disordered structure arose in poly (vinyl chloride) composites containing sodium type of montmorillonite, while a fine dispersion of partial to nearly full exfoliation of individual montmorillonite layers in poly (vinyl chloride) matrix was observed when this clay was organically modified. Finally, the influence of different mixing time (in extruder) on nano‐phase morphology was surveyed.

Poly(vinyl chloride)/metallic oxides/organically modified montmorillonite nanocomposites: Preparation, morphological characterization, and modeling of the mechanical properties

“…16,[18][19][20][21][22][23] It is a natural MMT, modified with a methyl-2-hydroxyethyl based quaternary ammonium salt, coupled to a fatty chain of animal origin (tallow), with approximately 65% C 18 , 30% C 16 and 5% C 14 . 26 This clay has, as a reference, an interlayer spacing value (d 001 ) of 1.85 nm (XRD) and was incorporated in 2.5 and 5 wt % dosages.…”

Nanocompósitos de PVC com argila organicamente modificada: efeitos do processamento e do método de incorporação da argila

“…A argila utilizada neste estudo foi a Cloisite ® 30B, fornecida pela Southern Clay Minerals, Inc. (EUA), e amplamente utilizada em diversos outros estudos envolvendo a obtenção de nanocompósitos de PVC [16,[18][19][20][21] . Trata-se de uma montmorilonita natural, modificada com um sal de amônio quaternário baseado em metil-2-hidroxietil, acoplado a uma cadeia graxa de origem animal (sebo), contendo aproximadamente 65% C 18 , 30% C 16 e 5% C 14 [24] .…”

“…Este deslocamento do pico de difração principal da O-MMT, para valores menores de ângulo 2θ, é um importante indicativo do aumento do espaçamento entre as lamelas do silicato, resultante da intercalação de moléculas dos plastificantes e/ou de cadeias do PVC nas galerias da argila. Resultados de outros autores [16,[18][19][20][21][22][23] , sempre utilizando DOP como plastificante, indicam valores diversos para d 001 , variando entre 3,1 até 4,9 nm; ou seja, da mesma ordem de grandeza que os obtidos neste estudo.…”

“…A abordagem de se utilizar o DOP como agente intercalador da argila foi também explorada por Kovarova e colaboradores [19] . Utilizando-se de dois tipos de argila (montmorilonita sódica ou Na-MMT e O-MMT Cloisite ® 30B), prepararam uma mistura das mesmas com DOP por 30 minutos a 80 °C.…”

Poly(Vinyl Chloride) Nanocomposites Prepared in the Suspension Polymerization Process. Part I. PVC Filled with Hybrid Nanofiller

“…Majority of them concerns the nanofiller introduction in polymer processing or via melt blending. At first mainly the clays: montmorillonite (MMT) or bentonite [1][2][3][4] were used as nanofillers but also precipitated calcium carbonate [5][6] were tested. The clays are concerned not only as modifiers of polymer mechanical properties but also their effect on flame retardancy [7] and/or reduction of smoke evolution were studied.…”