Iranian Researchers Enhance Plastic with Tea Waste

A team of Iranian researchers has utilized black tea waste as an eco-friendly and recyclable additive to improve the mechanical properties of polylactic acid (PLA), a type of biodegradable thermoplastic.

According to Mehr News Agency, PLA is a bioactive, biodegradable thermoplastic derived from renewable resources like corn starch, tapioca, or sugarcane.

Mehdi Badaqi from Nottingham Trent University in the UK, alongside Javad Khodad Hetakposhti, Naser Kordani, and Mohammad Akbarzadeh Pasha from the University of Mazandaran, developed a method to treat black tea waste with warm water to remove its color. The tea waste was then ground into a fine powder, which was mixed with PLA using an extruder.

Samples of PLA and biocomposites containing 3% to 5% tea waste were created with a hot press at 200°C, producing strands suitable for 3D printing. Scanning electron microscope images showed that the tea particles were evenly dispersed in the PLA matrix, especially in the 3% tea-PLA composite.

Tensile tests indicated that the 3% tea biocomposite had the highest mechanical performance, with a tensile strength of 67 MPa—a 34% increase compared to pure PLA. Thus, this PLA-tea biocomposite offers a promising, eco-friendly alternative to traditional PLA.