The effect of polyoxypropylene‐montmorillonite intercalates on polymethylmethacrylate

Abstract

Polymethylmethacrylate (PMMA)-layered silicate nanocomposites have been prepared by in situ polymerization of commercial type of methylmethacrylate monomer (MMA), for denture base material, into organoclay. Organoclay was prepared through an ion exchange process between sodium cations in montmorillonite and NH 3 1 groups in polyethertriamine hydrochloride and polyoxypropylene triamine hydrochloride with different molecular weight (5000, 440). X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) have been used to investigate the structure of the resulting composites. Both intercalated and exfoliated nanocomposites were obtained depending on the type and amount of organoclay. The thermal decomposition temperatures of the nanocomposites were found to be higher than that of pristine polymer. PMMA was strongly fixed to inorganic surfaces, due to cooperative formation of electrostatic bonding between NH 3 1 group and negatively charged surface of layered silicate and amide linkage between PMMA and polyethertriamine or polyoxypropylene triamine. The effect of the organoclay on the hardness, toughness, tensile stress, and elongation at break of the polymer was studied and was compared with pristine polymer. The hardness and Izod impact strength of PMMA-organoclay nanocomposites were enhanced with the inclusion of clay. Tensile properties appear to be enhanced at certain organoclay content. However, the water absorption is slightly higher than the pristine PMMA.

Physical and mechanical properties of nanocomposite barrier film containing encapsulated nanoclay

“…Water uptake of the as‐prepared latex films was measured according to the following procedure: the dry films were weighed ( m 1 ) and immersed in deionized water for 48 h. After the storage in water, the films were blot‐dried and weighed ( m 2 ) 18, 23. The water uptake was then calculated as follows: which represents the adsorbed water percentage on the surface and absorbed into the nanocomposite.…”

“…The platelet structure of the nanoparticles increases the tortuosity of the path for the diffusion of oxygen, water, and other gases and liquids17 throughout the nanocomposite. These layered silicate/polymer nanocomposites, as advanced materials, have also been reported to offer high stiffness and high heat resistant superior to conventional reinforced composites attributed to the high surface area between the silicate layers and polymeric material 10, 18…”

Fabrication and characterization of nanoclay-reinforced thermoplastic composite films

“…Independent of the filler concentration, both the hardness and Izod impact strength values increased, while the tensile properties were enhanced only for a certain clay content. 11 Vasiliu and her co-workers investigated the optical transparency characteristics of PMMA/MMT films. According to their results, the layered silicate/PMMA films had an optical transmission of greater than 80 % in the visible-light region.…”

Reinforcement of polymethyl methacrylate denture base resin with ZnO nanostructures

“…The first approach is to increase the strength of denture base polymer by adding a cross‐linking agent of poly‐functional monomer such as polyethylene glycol dimethacrylate. The second approach is to devise a reinforcement of denture base polymer with rods or fibers such as rubber phase, metal oxides, metal wires or metal nets, or clays . There are many factors such as matrix structure, dispersed phase content, shape, size, and distribution having a leading effect on the mechanical properties of reinforced resin …”