Effects of concentration and surface silanization of barite on the mechanical and physical properties of poly(lactic acid)/barite composites

Abstract

Neat and surface silanized barite (BR) was compounded with poly(lactic acid) (PLA) at the loading range of 5, 10, 15, and 20 wt% by melt blending process. Surface characteristics of BR samples were examined by infrared spectroscopy in attenuated total reflectance mode. Mechanical, thermal, water resistance, melt flow, and morphological characterizations of composites were performed by tensile and impact tests, dynamic mechanical analysis, water absorption test, melt flow rate (MFR) test, and scanning electron microscopy (SEM) analysis, respectively. BR additions lead to increase in tensile strength and modulus of PLA. The maximum improvement is obtained for 15 wt% of silanized BR containing composite. In contrast, percent elongation of PLA decreases with the incorporation of BR. Treated BR-loaded composites give higher impact energy values compared to untreated BR. Impact performance of composites increases with concentration. Silanized BR-filled composite at 5 wt% concentration exhibits higher storage modulus than unfilled PLA, where other composites yield relatively lower values in the case of storage modulus. Glass transition temperature of PLA extends to higher values by the addition of BR. Inclusions of BR samples cause a slight decrease in MFR of unfilled PLA. Water absorption of composites is found to be higher than that of PLA. Silanized BR-filled composites display lower water absorption values compared to untreated BR, thanks to hydrophobic nature of Si containing surface. According to SEM microimages of composites, more homogeneous dispersion in PLA matrix is achieved for treated BR particles than neat ones due to enhancement for interfacial adhesion of BR to PLA after silanization.

Effect of the Antimicrobial Agents Peppermint Essential Oil and Silver Nanoparticles on Bone Cement Properties

“…More homogeneous distribution of barite can be correlated with improved mechanical properties, such as the elastic modulus in flexure and the flexural strength. This is coherent with the experimental evidence obtained from the mechanical tests carried out in this work and also in good agreement with the literature results, as barite is a well-known additive for polymers-based composites, able to improve mechanical properties and, in particular, tensile strength and hardness if homogeneously distributed within the composite [ 50 , 51 ].…”

Advances in Natural-Fiber-Reinforced Composites: A Topical Review

“…Thus, crosslinks between the matrix polymer and fibers are formed with a uniform molecular hydrocarbon chain, which restrain the fiber with the matrix material when a load is applied. The silane treatment significantly increases the specific strength of the natural-fiber composites [85][86][87][88][89] The benzoylation treatment involves the use of benzoyl chloride to reduce the hydrophilic nature of natural fibers, which significantly improves the thermal stability and interfacial adhesion between the fiber surface and matrix [90][91][92].…”

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

“…The main reason of finding lower water absorption for modified mineral containing samples compared to neat ones is the hydrophobic character of silane layer. [60][61][62][63] Silane coating on mineral surface gave resistant against water molecules, hence silane modified BRT and BNT absorb much less water than neat ones in composite system. The lack of adhesion between polymer matrix and unmodified mineral surface might be the another reason since the poor adhesion contributes to form micro-voids on fillerpolymer interface and water molecules penetrate through these micro-voids by the help of capillary action.…”