Shear Rheology and Molecular Properties of Biobased Adhesives Through Molecular Dynamics Simulation

Agbogo Victor,Muktari Suleiman,Sunday Simeon,Sunmonu Olufemi,Dauda Benjamin,Rajesh Haldar

doi:10.47514/phyaccess.2021.1.1.002

Agbogo Victor, Muktari Suleiman + Show 4 more

Open Access

https://doi.org/10.47514/phyaccess.2021.1.1.002

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Abstract

The study of shear rheology and molecular architecture through molecular dynamics simulation of starch-based and gelatin-based adhesives formulated from Eleusine coracana, and cow hide has been successfully achieved. This research has revealed that esterification of natural dextrins with 20 % polyvinyl acetate (PVAc) will yield adhesives product with improved gel properties suitable for applications. Method of extraction, production of the adhesives by varying the quantity of fatty acid ester and quality assessment was performed and 20% PVAc incorporation found to be suitable for application. The physical features of the macromolecular complexes formed by the synergistic interaction of starch/gelatin and PVAc in the presence of tetraethylamine (TEA) has been studied from the rheological point of view. On examining the impact of the molecular structure and electronic properties of the adhesive molecules on the adhesive efficiency, quantum chemical calculations were carried out. Rheological analysis shows the adhesives are consistent and the computed free energy obtained from molecular dynamics simulation reveals that the adhesive molecules are spontaneous, hence efficient.

Highlights

Adhesives are used to join surfaces, typically by changing their phase from liquid to solid
The computational quantum mechanics (QM) and molecular dynamics (MD) investigations were carried out to obtain a detailed electronic/atomic scale insight into the experimentally found observations; in particular, the chain−chain interactions governing the behavior of Eleusine coracana (ECS)/ polyvinyl acetate (PVAc) systems
On examining the impact of the molecular structure and electronic properties of the adhesive molecules on the adhesive efficiency, quantum chemical calculations were carried out utilizing density functional theory (DFT) adopting the B3LYP function with the 6-31G + (d, p) basis set for all molecules, using the Hyperchem

Summary

INTRODUCTION

Adhesives are used to join surfaces, typically by changing their phase from liquid to solid. Molecular rheology is the missing link between the macromolecular structure of polymeric materials and their viscoelastic properties in the melt state It complements the engineering or continuum mechanics aspects of rheology, which generally ignores the molecular details of the objects under study [2]. Gelatin is a protein obtained by boiling skin, tendons, ligaments, and/ or bones with water It is an irreversibly hydrolyzed form of collagen, wherein the hydrolysis reduces protein fibrils into smaller peptides; depending on the physical and chemical methods of denaturation. The computational QM and MD investigations were carried out to obtain a detailed electronic/atomic scale insight into the experimentally found observations; in particular, the chain−chain interactions governing the behavior of Eleusine coracana (ECS)/ PVAc systems These techniques allow us to attain microscopic view of adhesives characteristics and to elucidate new information, such as inter/intramolecular hydrogen bonds, interaction. PHYSICSAccess energy and correlation between ECS/ PVAc or BGT/ PVAc, which cannot be achieved through experimental efforts

FORMATION OF ADHESSIVE FROM NATURAL RESINS

Adhesive Rheology Test

Quantum Molecular Simulations

Quantum Chemical Calculations

Rheology of the Adhesives Formulation

CONCLUSION