New Synthesis Routes toward Improvement of Natural Filler/Synthetic Polymer Interfacial Crosslinking.

Mahmoud M A Nassar,Tasneem Pervez,Nasr Al-Hinai,Belal J Abu Tarboush,Khalid I Alzebdeh

doi:10.3390/polym14030629

Mahmoud M A Nassar, Tasneem Pervez + Show 3 more

Open Access

https://doi.org/10.3390/polym14030629

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Abstract

Among the critical issues dictating bio-composite performance is the interfacial bonding between the natural fibers and polymer matrix. In this regard, this article presents new synthesis routes comprising the treatment and functionalization of both date palm powder (DPP) filler and a polypropylene (PP) matrix to enhance filler–polymer adhesion in the newly developed bio-composites. Specifically, four bio-composite forms are considered: untreated DPP filled PP (DPP-UT/PP), treated DPP filled PP (DPP-T/PP), treated DPP filled functionalized PP using 2-isocyanatoethyl methacrylate (DPP-T/PP-g-IEM), and treated and functionalized DPP using 4-toluenesulfonyl chloride filled functionalized PP using 2-acrylamide ((DPP-T)-g-TsCl/PP-g-AcAm). The functional groups created on the surface of synthesized PP-g-IEM react with activated hydroxyl groups attached to the filler, resulting in chemical crosslinking between both components. Similarly, the reaction of TsCl with NH2 chemical groups residing on the mating surfaces of the filler and polymer generates an amide bond in the interface region. Fourier transform infrared spectroscopy (FTIR) is used to confirm the successful coupling between the filler and polypropylene matrix after applying the treatment and functionalization schemes. Owing to the introduced crosslinking, the DPP-T/PP-g-IEM bio-composite exhibits the best mechanical properties as compared to the neat polymer, unfunctionalized polymer-based bio-composite, and (DPP-T)-g-TsCl/PP-g-AcAm counterpart. The applied compatibilizers assist in reducing the water uptake of the manufactured bio-composites, increasing their durability.

Highlights

Bio-composites have undergone significant development in the last few decades
To the best of the authors’ knowledge, this study reports for the first time a functionalization scheme for PP with a 2-isocyanatoethyl methacrylate (IEM) compatibilizer to produce urethane bonding with the natural filler
The Fourier transform infrared spectroscopy (FTIR) spectra of the three samples show the presence of water, as revealed by the peak at 3372 cm−1, which is ascribed to the stretching frequency of the hydroxyl group of the natural filler (OH)

Summary

Introduction

Bio-composites have undergone significant development in the last few decades. these materials are presently being investigated for various engineering applications. When surface contaminants and hydroxyl group elements, such as pectin, lignin, and hemicellulose, are adequately extracted from the fibers, the interaction between the natural fibers and its polymer matrix improves [21] Numerous approaches, such as fiber treatment, inclusion of nano-fillers, and hybridization, have been developed to circumvent these restrictions. The utilization of these processes to develop natural fiber composite materials in recent years has expanded their range of applications to include structural, home, aerospace, sports, automotive, and other industries [22,23]. Materials the effectiveness of the newly established techniques for chemical bonding between the DPP filler and PP matrix

Materials and Methods

Chemical Functionalization

PP-g-IEM

Bio-Composite Characterization

Chemical Characteristics

Water Absorption