Malaysian Journal of Analytical Sciences Vol 21 No 3 (2017): 754 - 761

DOI: https://doi.org/10.17576/mjas-2017-2103-25

 

 

 

CELLULOSE NANOCRYSTALS WITH ENHANCED THERMAL STABILITY REINFORCED THERMOPLASTIC POLYURETHANE

 

(Nanokristal Selulosa Dengan Ketahanan Haba Yang Tinggi Berasaskan Poliuretina  Termoplastik)

 

Khairatun Najwa Mohd Amin¹*, Pratheep Kumar Annamalai², Darren Martin²

 

¹Faculty of Chemical and Natural Resources Engineering,

Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia

²Australian Institute for Bioengineering and Nanotechnology (AIBN), Corner College and Cooper Rds (Bldg 75),

The University of Queensland, Brisbane QLD 4072 Australia

 

*Corresponding author: knajwa@ump.du.my

 

 

Received: 28 November 2016; Accepted: 5 February 2017

 

 

Abstract

Melt compounding processing approach for incorporating cellulose nanocrystals (CNC) into thermoplastic polyurethane (TPU) has not well been explored. This is primarily due to the poor thermal stability and dispersibility of CNCs. As they are typically obtained from sulphuric acid hydrolysis, they give rise to degradation and discolouration of the extruded nanocomposites. The investigation of this research demonstrates sulphuric acid hydrolysis (CNC-S), phosphoric acid hydrolysis (CNC-P) and a novel non-hydrolytic high energy bead milling method (CNC-MC) into a polyether based thermoplastic polyurethane via melt compounding using twin screw extruder. The TPU film incorporated with CNC-S obviously shows the sign of CNC degradation where TPU film was changed to brown colour. The tensile strength of TPU reinforced with CNC-S, CNC-P and CNC-MC shows 18%, 16% and 14% of improvement at CNC loading of 0 to 1 wt.% upon host polymer. CNCs isolated via mild acid hydrolysis and mechanical milling methods, can be easily processed via large scale melt-processing techniques for reinforcing thermoplastic polyurethane without affecting their physical appearance and elastic properties.

 

Keywords:  cellulose nanocrystals, thermoplastic polyurethane, nanocomposites

 

Abstrak

Kajian mengenai penggunaan nanokristal selulosa (CNC) di dalam termoplastik poliuritena (TPU) amat jarang diterokai. Ini adalah kerana CNC mempunyai ketahanan haba yang rendah. CNC yang dihasilkan melalui proses hidrolisis asid sulfurik mudah terdegradasi apabila digabungkan dengan polimer yang melalui proses meramu pencairan umumnya menggunakan suhu pemprosesan yang tinggi. Kajian ini menggunakan CNC yang dihasilkan daripada hidrolisis asid sulfurik (CNC-S), asid fosforik (CNC-P) dan kaedah novel pengisaran manik (CNC-MC) ke dalam poliuretana termoplastik berasaskan berasas polieter melalui proses meramu pencairan. Filem TPU yang digabungkan dengan CNC-S jelas menunjukkan tanda degradasi CNC apabila filem TPU bertukar warna kepada coklat. Kekuatan tegangan TPU diperkukuhkan dengan CNC-S, CNC-P dan CNC-MC menunjukkan 18%, 16% dan 14% peningkatan pada muatan CNC 0-1 wt.% di dalam komposit. CNC yang dihasilkan melalui hidrolisis asid berkekuatan sederhana dan melalui kaedah mekanikal boleh diproses melalui teknik meramu pencairan yang berskala besar dan mampu meningkatkan kekuatan poliuretana termoplastik tanpa menjejaskan penampilan fizikal mereka dan sifat elastiknya.

 

Kata kunci:  nanokristal selulosa, poliuritena termoplastik, nanokomposit

 

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