The Role of Inorganic-Organic Bio-Fillers Containing Kraft Lignin in Improvement in Functional Properties of Polyethylene

Abstract

In this study, MgO-lignin (MgO-L) dual phase fillers with varying amounts of lignin as well as pristine lignin and magnesium oxide were used as effective bio-fillers to increase the ultraviolet light protection and enhance the barrier performance of low density polyethylene (LDPE) thin sheet films. Differential scanning calorimetry (DSC) was used to check the crystalline structure of the studied samples, and scanning electron microscopy (SEM) was applied to determine morphological characteristics. The results of optical spectrometry in the range of UV light indicated that LDPE/MgO-L (1:5 wt/wt) composition exhibited the best protection factor, whereas LDPE did not absorb ultraviolet waves. Moreover, the addition of hybrid filler decreased the oxygen permeability factor and water vapor transmission compared with neat LDPE and its composites with pristine additives, such as lignin and magnesium oxide. The strong influence of the microstructure on thin sheet films was observed in the DSC results, as double melting peaks were detected only for LDPE compounded with inorganic-organic bio-fillers: LDPE/MgO-L.

The Influence of TiO2–Lignin Hybrid Fillers in Low-Density Polyethylene Composites on Photocatalytic Performance and UV-Barrier Properties

“…In some cases, introducing fillers into the polymer matrix also has economic reasons [ 6 ]. A variety of products are used to produce polymer composites, including biopolymers, such as lignin [ 1 , 7 , 8 , 9 , 10 , 11 , 12 ] and cellulose [ 13 , 14 , 15 , 16 , 17 , 18 , 19 ]; inorganic substances, e.g., titanium dioxide [ 20 , 21 , 22 , 23 ]; and hybrid materials, e.g., MgO/lignin [ 24 ] or TiO 2 /lignin [ 25 ].…”

“…Moreover, the advantage of using the mentioned biopolymer is the fact that lignin is an inexpensive, natural, and biodegradable material, which is a waste product in the paper industry and in biorefineries [ 7 ]. However, polyolefins and lignin in their original natural form, due to the highly hydrophilic nature of the biopolymer, are immiscible; therefore, additional modifications are required to change the properties of lignin and improve the dispersion of its particles in the polymer matrix [ 7 , 24 ].…”

Recent Advances in Development of Waste-Based Polymer Materials: A Review

“…Many scientific reports about grinding and granulation of waste polymers and rubber are still rather limited compared to other processing methods. Research about mechanochemistry in waste management [25] combined with novel technologies related to the synthesis of modified or hybrid fillers [26,27] or polymeric materials dedicated for special applications (e.g., polymeric powders dedicated for selective laser sintering 3D printing) indicate further development of grinding and granulation technologies in the coming years (especially those working in a continuous manner). Hoyer, Kroll, and Sykutera [24] compared the cryogenic grinding of waste tire rubber (passenger car and truck tires) technology with different ambient grinding processes, such as solid-state shear extrusion; cracker mill; wet grinding; or hyperboloidal cutting mill.…”

Polypropylene/Lignin/POSS Nanocomposites: Thermal and Wettability Properties, Application in Water Remediation

“…Most of the lignin is burned or discharged into rivers, which threatens the environment [ 23 , 24 ]. Lignin is known as the most abundant aromatic polymer in nature, with a complex and amorphous polyphenolic molecule composed of many functional groups, enhancing its potential for usage in several material applications and production of high-added-value products [ 26 , 27 ].…”