Modification of Cellulose Nanocrystals With 2-Carboxyethyl Acrylate in the Presence of Epoxy Resin for Enhancing its Adhesive Properties

Amjad Ali,Li Guo,Fazal Haq,Sehrish Manan,Jieyuan Zheng,Qaiser Javed,Muhammad Naeem Shah,Ameer Ali Kubar,Mahamed F Awad,Fan Hong,Asmat Ullah,Tariq Aziz

doi:10.3389/fbioe.2021.797672

Abstract

Cellulose nanocrystals (CNCs) have unparalleled advantages in the preparation of nanocomposites for various applications. However, a major challenge associated with CNCs in nanocomposite preparation is the lack of compatibility with hydrophobic polymers. The hydrophobic modification of CNCs has attracted increasing interest in the modern era standing with long challenges and being environmentally friendly. Here, we synthesized CNCs by using cotton as raw material and then modified them with 2-carboxyethyl acrylate to improve their corresponding mechanical, adhesive, contact angle, and thermal properties. Different concentrations (1–5 wt%) of CNCs were used as modifiers to improve the interfacial adhesion between the reinforced CNCs and E-51 (Bisphenol A diglycidyl ether) epoxy resin system. CNCs offered a better modulus of elasticity, a lower coefficient of energy, and thermal expansion. Compared with the standard sample, the modified CNCs (MCNCs) showed high shear stress, high toughness, efficient degradation, thermal stability, and recycling due to the combined effect of the hyperbranched topological structure of epoxy with good compatibility. The native CNCs lost their hydrophilicity after modification with epoxy, and MCNCs showed good hydrophobic behavior (CA = 105 ± 2°). The findings of this study indicate that modification of CNCs with 2-carboxyethyl acrylate in the presence of epoxy resin and the enhancement of the features would further expand their applications to different sectors.

Highlights

Cellulose nanocrystals (CNCs) or nanoparticles have drawn a lot of attention due to their abundance, biocompatibility, renewability, and excellent mechanical properties, paving the way to innovative and sustainable applications
Cotton was supplied by the Guangzhou Liqi textile industry (China). 2-Carboxyethyl acrylate was purchased from ChemSrc China (98% purity)
A TEM view of the native CNCs produced from cotton through acid hydrolysis is shown in Figure 4A, which shows the typical showed a cluster-like behavior, which may be higher and improve the interface, which is reflected in the rough surface layer

Summary

Introduction

Cellulose nanocrystals (CNCs) or nanoparticles have drawn a lot of attention due to their abundance, biocompatibility, renewability, and excellent mechanical properties, paving the way to innovative and sustainable applications. CNCs are crystalline and rod-shaped, depending on their source These have been used as reinforcing agents due to their excellent mechanical properties (Dhar et al, 2012; Aziz et al, 2020a; Cao et al, 2020; Satam et al, 2020). The cellulose-based aerogels are novel third-generation aerogels that have recently attracted much attention due to their high adsorption efficiency, eco-friendly nature, and cost-effectiveness Such aerogels acquire several properties, especially with their low cost and chemical stability (Aziz et al, 2021a; Aziz et al, 2021b; Aziz et al, 2021c), and are used as modifiers to enhance the interfacial adhesion between the matrix of nanocrystals (Aziz et al, 2019b; Li et al, 2020; Rincón-Iglesias et al, 2020). The uses of CNCs as a modifier have been studied in combination with a wide range of natural or synthetic polymers, especially in an epoxy emulsion (Dastjerdi et al, 2018; Kamtsikakis et al, 2021)

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Results

Conclusion