Properties of microfibrillar cellulose filled thermoplastic natural rubber: Morphology, mechanical properties, and melt flow index

Ihda Novia Indrajati,Dwi Wahini Nurhajati,Indiah Ratna Dewi

doi:10.20543/mkkp.v36i2.6522

Abstract

Microfibrillar cellulose (MFC) was derived from local pineapple leaf fiber (PALF) and employed as filler in thermoplastic natural rubber (TPNR), that was a blend of natural rubber (NR) and polypropylene (PP). The blends were prepared by dynamic vulcanization. The performance of MFC-filled TPNR on morphology, mechanical properties, aging behavior, and melt flow index (MFI) were evaluated in this study. MFC was synthesized through several processing steps, including extraction, bleaching, acid hydrolysis, and ball-milling mechanical treatment. The blends were made in a fixed ratio of 60/40 (NR/PP) with various fiber concentration. The blending of NR/PP was performed by Rheomix internal mixer at 160 °C for 15 minutes with turning rotor of 90 rpm. The results showed that the particle size distribution of MFC was rather broad with some web-like agglomerates. An improvement in tensile strength was observed at low fiber loading. Fiber improved the tear strength, but decreased the elongation at break as expected. The hardness was independent to fiber loading. The morphology of fractured sample of TPNR showed fibrous structure indicating plastic deformation. MFC decreased the melt flow index of TPNR. The MFI value ranges between 3 – 5 g/10 min. One phr of MFC resulted in ultimate mechanical properties with considerable melt flow.

Highlights

Thermoplastic elastomer (TPE) is a class of polymer that combines processing properties of thermoplastic with the functional performance of rubber
TPE can be prepared through simple blend which results in thermoplastic elastomer polyolefin (TPO), and crosslinked elastomeric phase which results in thermoplastic vulcanizate (TPV)
The mechanical properties and melt flow index of the thermoplastic natural rubber (TPNR) were studied with respect of Microfibrillar cellulose (MFC) loading

Summary

Introduction

Thermoplastic elastomer (TPE) is a class of polymer that combines processing properties of thermoplastic with the functional performance of rubber. It can be processed in conventional thermoplastic molding machines, but remains elastic characteristic of rubber. TPE can be prepared through simple blend which results in thermoplastic elastomer polyolefin (TPO), and crosslinked elastomeric phase which results in thermoplastic vulcanizate (TPV). TPV contains crosslinked rubber phase which is finely dispersed in continuous thermoplastic matrix. Dynamic vulcanization is the most common process to prepare the TPV. It is the selective crosslinking process of rubber phase during melt mixing with a thermoplastic material under high shear and deformation rate.

Methods

Results

Conclusion