Preparation, Structural Characterization, and Thermomechanical Properties of Poly(methyl methacrylate)/Organoclay Nanocomposites by Melt Intercalation

Abstract

Poly(methyl methacrylate) (PMMA) based nanocomposites were synthesized by melt intercalation technique using organoclays (Cloisite 30B and Cloisite 20A) as fillers. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to determine the dispersion and the morphology of the nanocomposites obtained. Thermomechanical tests including tensile test and dynamic mechanical analysis (DMA) were used to evaluate the Young's modulus, storage modulus and the glass transition temperature. Thermogravimetric analysis (TGA) is conducted on the poly(methyl methacrylate) based nanocomposites to determine their thermal stability. The effect of filler content is studied by considering samples with filler contents varying from 1 to 5 wt%. The mechanical properties obtained from the tensile tests show an increase in the Young's modulus and a decrease in the strain to failure as function of the nanoclays concentration. Relative to the pure poly(methyl methacrylate), the dynamic mechanical analyses show an increase in the storage modulus and the glass transition temperature of both nanocomposites. The thermogravimetric analysis shows an increase of the thermal stability of both nanocomposites.

Investigation of the Stiffness and Yield Behaviour of Melt-Intercalated Poly(methyl methacrylate)/Organoclay Nanocomposites: Characterisation and Modelling

“…In the both cases the yield stress (defined as the maximum stress) appears to increase with the organoclay concentration. This result is in agreement with the observations reported in our previous work 12 where we mentioned the restriction of polymer chains motion in both nanocomposites due to the presence of organoclay layers. The behaviour of both organoclay nanocomposites materials is very similar to the typical behaviour of most thermoplastics.…”

“…The effective activation volume of both nanocomposites appears to decreases slightly (see Table IV) with increasing organoclay concentration due to the confinement of PMMA chain segments. 12 In fact it was demonstrated in our previous work 12 that the glass transition temperature of both organoclay nanocomposites shifts to higher values. However the effective activation energy increases slightly with increasing clay concentration (see Table IV).…”

“…Detailed information about the material fabrication, characterization and thermomechanical properties (glass transition temperature, storage and Young's modulus and thermal stability) has been reported elsewhere. 12 The tensile tests were carried out with an instron tensile testing machine (model 4204, USA), at temperatures from 40 to 100 C and at constant strain rates from 10 −4 to 10 −2 S −1 . Specimens for experimental analysis are obtained by injection molding.…”

“…This is mainly due to the fact that during the fabrication of samples by injection molding, the organoclay layers in the intercalated PMMA/C20A organoclay nanocomposites (who generally do not have better mechanical properties than the exfoliated PMMA/C30B) were very oriented in the tensile loading direction. 12 …”

Dynamic Compressive Behavior of a Melt Mixed Polypropylene/Organoclay Nanocomposites

“…These materials are stimulating both fundamental and applied research because the incorporation of layered silicate into the polymeric matrix provides several improvements in physical and mechanical properties 11,2). Improvements in properties include increase in Young's modulus, yield stress, heat resistance, gas barrier, and flame retardancy as compared with conventional composites or unfilled polymers [3][4][5][6][7][8]. Among the different methods used for the preparation of polymer clay nanocomposites, the melt interaction technique is one of ihe most useful methods [7,9].…”