Recent advances in compatibilization strategies of wood-polymer composites by isocyanates

Abstract

Wood-polymer composites technologies are gaining more and more attention in the scientific community, positively affecting the increase in their industrial applications, for example, automotive, building, 3D printing, etc. Many research works are focused on the improvement in matrix–lignocellulosic filler interactions to produce highly filled composites with satisfying performance properties. In this field of research, using isocyanates due to their versatile structure and functionality seems to be a very promising approach. This paper aims at reporting on recent advances in compatibilization strategies of wood-polymer composites by isocyanates. Particular attention is focused on the correlation between isocyanate structure, as well as modification conditions on the matrix–lignocellulosic filler interactions and their impact on the structure–property relationships of wood-polymer composites. Furthermore, limitations and future research trends related to applications of isocyanate to wood-polymer composites technologies are also discussed.

Mater-Bi/Brewers’ Spent Grain Biocomposites—Novel Approach to Plant-Based Waste Filler Treatment by Highly Efficient Thermomechanical and Chemical Methods

“…Moreover, slight broadening of these signals for increasing extrusion temperature, and mainly for IPDI modification, may indicate the increase in the number of N-H bonds present in amine and amide groups, whose signals are noted above 3300 cm −1 [ 56 ]. Such an effect may be related to the Maillard reactions and the generation of urethane bonds between hydroxyls of fillers and isocyanate groups [ 40 ]. Peaks typical for the symmetric and asymmetric stretching vibrations of C-H bonds in CH 2 and CH 3 end groups were noted at 2854 and 2922 cm −1 [ 57 ].…”

“…To ensure more substantial improvement, it is beneficial to provide covalent bonding at the interface, which could be provided by the chemical treatment and introduction of functional groups on the fillers’ surface [ 40 ]. Such an approach could overcome the drawbacks related to insufficient interfacial adhesion and significantly enhance the performance of composites.…”

Enriching WPCs and NFPCs with Carbon Nanotubes and Graphene

“…Going forward, in future studies, a much more pragmatic approach to experimental planning needs to be adopted. It would be useful to consider the vast corpus of knowledge gathered in the manufacture of pure CNM and polymer composites [93][94][95][96], and to combine this with the state-of-the-art expertise already existing in the production of high-performance WPCs and NFPCs [97][98][99]. Such analysis could potentially help with the choice of specific CNMs, wood particles, compatible polymers, and methods of manufacture, as well as avoiding such issues as agglomeration or poor adhesion of components.…”

From Waste to Reuse: Manufacture of Ecological Composites Based on Biopolyethylene/wood Powder with PE-g-MA and Macaíba Oil

“…The compatibilizer PE-g-MA reacts with the hydroxyls of the wood powder and, at the same time, there is a physical entanglement with the BioPE polymer matrix chain. The macaíba oil has oleic acid in its constitution [51], which promotes interactions of hydrogen bonds with the hydroxyls present on the surface of the wood powder and plasticizes the composite, generating compatibility and increasing impact strength [52,53].…”