Preparation and Properties of Thermoplastic Polyurethane Composites Filled with Powdered Buckwheat Husks

Abstract

Bio-based fillers for the polymer composites are still interesting from the scientific and industrial point of view, due to their low cost and renewable nature. In this work partially green composites were obtained by the mixing of thermoplastic poly(ester-urethane) with the unmodified and modified (by acetylation) grinded buckwheat husks. Obtained biocomposites were characterized in the terms of their chemical structure (FTIR), microstructure (SEM), thermal stability (TGA), thermomechanical properties (DMTA), and selected mechanical properties. The results showed that introduction of grinded buckwheat husks (even if the amount is 60 wt%) permit retaining high values of tensile strength (around 8–10 MPa), but the increasing amount of applied filler is connected with the decreasing of elongation at break. It can result from good interaction between the polymer matrix and the bio-based filler (confirmed by high values of polymer matrix-filler interaction parameter determined from Pukánszky’s model for the tensile strength of composites). The applied chemical treatment results in changing of mechanical properties of filler and composites. Obtained results confirmed the possibility of using powdered buckwheat husks as filler for thermoplastic polyurethane.

Properties of Rigid Polyurethane Foam Filled with Sawdust from Primary Wood Processing

“…By-products from both the timber and agricultural industries have also become a source of fillers that can be used in the production of polymer-based composites [ 7 , 8 ]. Wood–Polymer composites (WPCs) combine the advantages of both synthetic polymers and lignocellulosic fillers [ 9 ].…”

“…The studies carried out so far show that agricultural waste is a material with high application potential in the production of composite PUR foams. It has been shown that waste products such as buckwheat husks [ 7 ], walnut shells [ 12 , 20 ], plum stones [ 22 ], straw fibre [ 24 ], hemp fibre [ 25 ], wheat slops [ 26 ], rapeseed cake [ 21 ], soy and potato protein [ 27 , 28 ], sugar beet pulp [ 15 ], egg shell [ 29 ], ground coffee [ 30 ], keratin chicken feathers [ 31 ] and many others have a beneficial effect on the properties of foams. Another source of naturally derived fillers is the timber industry.…”

Synthesis of composites based on waste natural Products and Polyurethane

“…(26,27). A schematic diagram for the set-up used is shown in Figure (15). All the measurement was carried out at chem-Dep.…”

“…Several different bio-based fillers were proposed, for example: hemp fiber, flax fibers, kenaf fiber], sugar palm fibers, roselle fibers, tea waste fibers, and cocoa pod husk fibers. Rice and buckwheat husks are examples of agriculture byproducts that can be applied as a filler in the preparation of polymer composites (14,15). On the other hand, the ablative properties of most polymers ablative composites (i.e., resistance to thermochemical corrosion and mechanical scouring as well as thermal stress caused by high-temperature and high-speed heat flux) are mainly determined by the structure of the polymer layer (16,17).…”

Failure Analysis of Abnormal Cracking of the Track Circuit Reader Antenna Baffle for High-Speed Trains

“…Due to its high hardness, good strength, high elasticity, wear resistance, tear resistance, and aging resistance [ 1 , 2 ], PUR is widely used [ 3 , 4 , 5 , 6 ]. However, it turns out that like other polymer materials [ 7 ], PUR also has its drawbacks.…”