Investigation of mechanical properties of nanocellulose reinforced synthetic polymer composite

K D H N Kahawita,D A S Amarasinghe,L Karunanayake,A M P B Samarasekara

doi:10.4038/tar.v30i2.8309

K D H N Kahawita, D A S Amarasinghe + Show 2 more

Open Access

https://doi.org/10.4038/tar.v30i2.8309

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Abstract

In Sri Lanka, a considerable percentage of agricultural waste such as rice straw and sugarcane bagasse is discharged to the environment without a commercial use and forms a huge organic environmental pollution. Therefore, the agricultural wastes can be used to extract cellulose and indirectly apply an additional value to the abundant priceless wastes. Nanocellulose is a cellulosic material which has at least one dimension in the nanometre range and has a potential for polymer reinforcement. Based on their structure nanocellulose extracted from plant species are categorised into two; nanofibrillated cellulose (NFC) and nanocrystalline cellulose (NCC). The present paper discussed the surface modification of NFC using Silane coupling agent (Si-69) and fabrication of silylated NFC reinforced polypropylene (PP) composites with different loadings of NFC from 0-5 wt. % by adding 0.5 wt. % per sample. The mechanical properties of the composite samples were compared with respect to neat PP and Scanning electron microscope (SEM), Fourier-transform infrared spectroscopy, X-ray diffraction, mechanical tests (tensile strength, percentage elongation at break, impact strength and hardness), percentage water absorption and melt flow index (MFI) were used to characterize the developed composites. The experimental results emphasize the wide improvement of mechanical properties with extremely narrow reduction of water absorption and processability of silylated NFC based PP than pure PP. The 3.5% silylated NFC reinforced PP composite indicated the highest improvement in mechanical properties such as hardness, tensile and impact strength, a 7.4%, 12.6%, and 86.1% higher than the neat PP, respectively.

Highlights

Natural fibres are used to reinforce with synthetic polymer composite due to the abundance, economic benefits and biodegradable properties (Samarasekara et al, 2018a; Samarasekara et al, 2018b; Samarasekara et al, 2014)
The 3.5% silylated nanofibrillated cellulose (NFC) reinforced PP composite indicated the highest improvement in mechanical properties such as hardness, tensile and impact strength, a 7.4%, 12.6%, and 86.1% higher than the neat PP, respectively
The peak at 2917 cm–1 demonstrates C-H stretching vibrations and the band shifted to high values from 2900 cm–1 which can be further proved the amorphous structure of nanocellulose

Summary

Introduction

Natural fibres are used to reinforce with synthetic polymer composite due to the abundance, economic benefits and biodegradable properties (Samarasekara et al, 2018a; Samarasekara et al, 2018b; Samarasekara et al, 2014). Plant cell wall contains lamella structure of cellulose microfibrils and after separation. Nanocellulose contains many favorable features than natural cellulose; such as distinctive tensile strength, high stiffness and Young’s modulus with lightweight (Dufresne 2013; Kalia et al, 2009). In respect to nanocrystalline cellulose (NCC), nanofibrillated cellulose (NFC) consists of a bundle of long chains, flexible cellulose molecules with high aspect ratio. Production of NFC reinforced Polypropylene (PP) composite could improve the performance of the material than pure PP. A proper surface modification is needed to improve the compatibility between the matrix and the reinforcement.

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Conclusion