Physical and mechanical performance of bentonite and barite loaded low density polyethylene composites: Influence of surface silanization of minerals

Abstract

In this study, two kinds of mineral fillers, bentonite (BNT) and barite (BRT), were incorporated into low density polyethylene (LDPE) by extrusion process. Silane treatment was applied to BRT and BNT surfaces in order to increase their compatibility with LDPE matrix. Surface characteristics of fillers were examined by Fourier transformed infrared spectroscopy (FTIR). LDPE-based composites were prepared at a constant concentration of 10%wt for each additives. Test samples were shaped by injection molding process. Mechanical, thermo-mechanical, water repellency, melt-flow and morphological characterizations of LDPE and its composites were performed by tensile and impact tests, dynamic mechanical analysis (DMA), water absorption test, melt flow index (MFI) measurements and scanning electron microscopy (SEM) technique, respectively. Test results showed that surface treatments led to increase for final properties of composites since they promoted to stronger adhesion between minerals and LDPE matrix compared to untreated ones. Tensile and impact strength values, storage modulus and glass transition temperature of LDPE were improved by inclusion of silane treated minerals. BRT and BNT additions caused no remarkable changes with regard to MFI of LDPE. Additionally, silane modified mineral filled composites exhibited remarkable water resistance behavior. According to SEM analysis of composites, silane treated BNT and BRT containing samples displayed homogeneous dispersions into LDPE phase whereas debondings were observed for untreated BNT and BRT filled composites due to their weak adhesion to polymer matrix.

Contribution of surface silanization process on mechanical characteristics of TPU‐based composites involving feldspar and quartz minerals

“…Si‐related peaks gave higher intensities for Si‐FLS compared to neat FLS thanks to the formation of a silane layer on the mineral surface. [ 25,26,33,34 ]…”

“…FLS and QRZ minerals were subjected to a silane modification process according to similar routes in the literature. [25,26] Silane treatment to FLS and QRZ minerals was applied by mixing powders in a 2 wt% APTES/ethanol solution at pH of 5.0 for nearly 150 min at room temperature and dried at a laboratory owen at 80 C overnight. Silanemodified FLS and QRZ samples were coded as Si-FLS and Si-QRZ, respectively.…”

“…Si-related peaks gave higher intensities for Si-FLS compared to neat FLS thanks to the formation of a silane layer on the mineral surface. [25,26,33,34] Since the composition of QRZ mostly consists of silicate (SiO 2 ) according to Table 1 (98.5%wt), the shoulder peaks observed around the wavelength of 800 cm À1 in Figure 2 were linked to Si O vibrations. The intensities of these peaks were found to be slightly increased after silane treatment.…”

The Influence of Selected Fillers on the Functional Properties of Polycarbonate Dedicated to 3D Printing Applications

“…An example of such a mineral is bentonite-a naturally occurring clay mineral with very small particle sizes and a high degree of plasticity [22]. Studies showed that the introduction of an additive to the polymer matrix has a positive effect on the thermal and mechanical properties of the composite, such as hardness, tensile strength and elongation [23][24][25][26].…”

The use of recycled low‐density polyethylene films from protective prepreg for the development of nanocomposites with bentonite clay

“…Furthermore, bentonite has a high sorbent property, expansion capacity, and high elastic modulus. Therefore, the incorporation of low levels of BNT in polymeric matrices can induce a decrease in water vapor permeability and increase the thermal, gas barrier and mechanical properties, which are desirable for application in packaging, the purpose of the present study 12,14 …”