The Impact of Filler Geometry on Polylactic Acid-Based Sustainable Polymer Composites

Abstract

Recently, biocomposites have emerged as materials of great interest to the scientists and industry around the globe. Among various polymers, polylactic acid (PLA) is a popular matrix material with high potential for advanced applications. Various particulate materials and nanoparticles have been used as the filler in PLA based matrix. One of the extensively studied filler is cellulose. However, cellulose fibres, due to their hydrophilic nature, are difficult to blend with a hydrophobic polymer matrix. This leads to agglomeration and creates voids, reducing the mechanical strength of the resulting composite. Moreover, the role of the various forms of pure cellulose and its particle shape factors has not been analyzed in most of the current literature. Therefore, in this work, materials of various shapes and shape factors were selected as fillers for the production of polymer composites using Polylactic acid as a matrix to fill this knowledge gap. In particular, pure cellulose fibres (three types with different elongation coefficient) and two mineral nanocomponents: precipitated calcium carbonate and montmorillonite were used. The composites were prepared by a melt blending process using two different levels of fillers: 5% and 30%. Then, the analysis of their thermomechanical and physico-chemical properties was carried out. The obtained results were presented graphically and discussed in terms of their shape and degree of filling.

Propolis and Organosilanes as Innovative Hybrid Modifiers in Wood-Based Polymer Composites

“…Composites with raw wood and wood treated with propolis extract exhibited very low values of strain and relatively low impact strength. Such results are typical for composites of thermoplastic polymers with lignocellulosic fillers described in literature [67][68][69][70], which are characterised by poor adhesion. However, in the case of composites treated by propolis-silane preparations very high values of elongation at break and high impact strength were recorded, which was particularly evident for the PP + EPP-TEOS/OTEOS system.…”

Hydrophilicity Affecting the Enzyme-Driven Degradation of Piezoelectric Poly-l-Lactide Films

“…Both etched and non-etched PLLA films have the same initial Young's modulus measured at 23 • C (2.4 GPa), comparable to values observed in the literature for PLA polymer [26], which confirms that alkali etching was performed only on the surface without compromising the inner parts (Figure 6a). After the enzymatic degradation, the values are significantly lowered for the non-etched samples, even after 5 days of degradation, where the modulus is lowered by 92% (190 MPa), while it is only 1% for the etched samples (Figure 6a).…”

Influence of Newly Organosolv Lignin-Based Interface Modifier on Mechanical and Thermal Properties, and Enzymatic Degradation of Polylactic Acid/Chitosan Biocomposites

“…Chitosan is a natural polymer that possesses polar hydrophilic properties, whereas PLA is a nonpolar hydrophobic polymer. The differences in the affinities and polarity diminished the interaction on the filler-matrix interface [ 34 ]. The modified PLA/chitosan biocomposite with PAA-g-OSL, on the other hand, demonstrated a greater strength than those of the neat PLA and the unmodified biocomposites, which indicates the enhanced interfacial adhesion upon the existence of PAA-g-OSL on the chitosan surface.…”