Rheological and mechanical characterization of poly (methyl methacrylate)/silica (PMMA/SiO2) composites

Abstract

The search for new materials with properties suitable for specific applications has increased the number of research studies to fill the market demands. The development of polymer composites by the addition of inorganic fillers to the poly(methyl methacrylate) (PMMA) increases the potential use of this polymer in various application fields. The main objective of this work was to study the rheological and mechanical behavior of composites obtained from the addition of silica in two different types of PMMA matrix: a common (PMMAc) and an elastomeric copolymer (PMMAel). The results showed that the addition of silica particles to the PMMA matrix promoted an increase in torque, a decrease in the melt flow index of composites and an increase in hardness compared to pure polymers. The composites also showed a reduction of the maximum tensile strength for composites with PMMAc matrix and maintenance of tensile strength for composites with PMMAel matrix. The average width of scratch decreased due to a change in wear mechanism, attributed to the increase of hardness in the composites obtained.

Preparation of poly(methyl methacrylate)‐Silica nanoparticles via differential microemulsion polymerization and physical properties of NR/PMMA‐SiO2 hybrid membranes

“…For the blend ratio of 60/40, the modulus at 300% strain of NR/PMMA‐SiO 2 was increased to 5.0 MPa, compared with unfilled NR (1.0 MPa). This is due to the high modulus of PMMA polymer and the reinforcement effect of silica (rigid particle) which reduced the flexibility of rubber chains, thus the material with higher silica content also exhibited higher modulus . The elongation at break of the nanocomposite membranes was decreased with increasing PMMA‐SiO 2 content.…”

Obtention of higher refractive index and transparent polymeric nanocomposite systems with small amounts of fillers for lenses application

“…However, the greater or lesser impact observed in each study may reflect changes in the content, dispersion and distribution of these particles. 44,45…”

Silica and its Peculiarities

“…43,44 As condições de reação (velocidade de adição dos reagentes, concentração, agitação, temperatura e pH) determinam as propriedades da sílica precipitada, nomeadamente, a dimensão das partículas. 45,46 A sílica precipitada pode ser usada para adsorção de impurezas em líquidos e gases, como aglutinante em concretos e cerâmicas e também como agente anti-aglutinante no setor de alimentos. 47…”

“…55 Assim, a sílica gel desempenha um papel importante na função de suporte para uma grande gama de substâncias com extensa aplicabilidade prática. 45,52 A modificação da sílica permite ainda a obtenção de compostos de maior versatilidade e com propriedades específicas relacionadas às espécies ligadas à sua superfície. 56 A sílica apresenta-se em unidades tetraédricas, com os grupos SiO4 distribuídos aleatoriamente (Figura 5).…”