Malays. J. Anal. Sci. Volume 30 Number 2 (2026): 1718

 

Research Article

 

Comparative impact of natural crosslinking, plasticization, and hydrophobic additives on the physicochemical properties of rice husk-starch biodegradable straws

 

Nur Irdina Kamarul Bahrin1, Rozaini Abdullah1,2*, Ku Syahidah Ku Ismail1,3, and Muhammad Akmal Amir4

 

1 Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis, 02600, Arau, Perlis, Malaysia

2 Centre of Excellence for Frontier Materials Research, Universiti Malaysia Perlis, No. 64-66, Blok B, Taman Pertiwi Indah, Jalan Kangar - Alor Setar, Kampung Seriab, 01000 Kangar, Perlis, Malaysia

3 Centre of Excellence for Biomass Utilization, Kompleks Pusat Pengajian Jejawi 3, Kawasan Perindustrian Jejawi, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia

4 Ada Biotech Sdn Bhd, Lot 5497, Tingkat Mak Mandin 4, Mak Mandin Industrial Estate, 13400 Butterworth, Pulau Pinang, Malaysia

 

*Corresponding author: rozainiabdullah@unimap.edu.my

 

Received: 24 September 2025; Revised: 30 March 2026; Accepted: 6 April 2026; Published: 28 April 2026

 

Abstract

Starch-based biodegradable straws offer a sustainable alternative to petroleum-based plastics, yet their practical application is limited due to poor water resistance and insufficient mechanical strength. In the present study, drinking straws made of corn starch, rice husk, carboxymethyl cellulose, and water were prepared using a twin-screw extrusion process. To systematically evaluate different chemical pathways, candelilla wax, glycerol, and citric acid were introduced separately to investigate the effect of hydrophobic modification, plasticization, and crosslinking under identical processing conditions. The resulting drinking straws underwent comprehensive physicochemical characterization, encompassing water uptake behavior, mechanical flexural performance, FTIR spectroscopy analysis, and thermogravimetric (TGA) profiling, followed by soil burial biodegradation. The candelilla wax formulation exhibited the lowest water absorption (53.90 ± 2.99%) and the highest flexural strength (16.54 ± 1.86 MPa), whereas the citric acid formulation achieved the lowest strength (9.33 ± 1.38 MPa), indicating increased brittleness. All formulations demonstrated biodegradability, with the control showing a degradation rate of 76.45 ± 8.27% after 28 days, while the modified formulations showed lower degradation due to limited moisture diffusion. Overall, hydrophobic modification via candelilla wax was the most balanced in performance by improving moisture resistance and mechanical stability while maintaining biodegradability.

 

Keywords: drinking straw, natural crosslinking, candelilla wax, biodegradable, water resistance

 

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