Waterloo: cellulose coating for paper cups withstood abrasion better than polyethylene in lab tests
A coating of cellulose acetate and cellulose nanocrystals replaced the polyethylene liner on lab paper samples. The authors say it could simplify paper recycling.
A team at the University of Waterloo, led by Shirley Tang, professor of chemistry, has developed a fully cellulosic barrier coating for paper hot-beverage cups. The study was published on 10 August 2026 in ACS Sustainable Chemistry & Engineering (DOI 10.1021/acssuschemeng.6c03064). The coating is cellulose acetate (CA) reinforced with cellulose nanocrystals (CNCs), and both components come from plants doi.org
ACS Sustainable Chemistry & Engineeringdoi.orgOpen source ↗. The work is an experimental study on coated paper samples.
The goal is to replace the polyethylene liner, which is derived from fossil fuels and complicates recycling of used cups. Because the coating and the cup are both cellulose-based, the authors say the material could reduce the need to separate plastic liners from paper doi.org
ACS Sustainable Chemistry & Engineeringdoi.orgOpen source ↗.
Structure and mechanical properties
The formulation was dispersed in a sealed, shear-free process and applied to porous paper by blade coating. The coatings form continuous surface layers that bridge macropores and partly integrate with the upper fiber network doi.org
ACS Sustainable Chemistry & Engineeringdoi.orgOpen source ↗. Spectroscopy showed physical blending of CA, CNCs and paper, with hydrogen-bonding interactions between them. Raman spectra showed shifts consistent with stronger bonding at the coating–substrate interface
doi.org
ACS Sustainable Chemistry & Engineeringdoi.orgOpen source ↗.
Thermogravimetry showed delayed main-chain degradation and higher char yield as CNC content increased. Tensile strength and modulus rose steadily with CNC content and peaked at 5 wt %. Toughness improved up to 3 wt % CNC doi.org
ACS Sustainable Chemistry & Engineeringdoi.orgOpen source ↗.
Barrier properties and abrasion
The coatings stayed intact during a five-day immersion in protic and aprotic, acidic and basic media, with no film lift-off or channel formation. Oxygen transmission with CA alone fell by more than an order of magnitude compared with uncoated paper. With CNCs it reached low-permeability regimes doi.org
ACS Sustainable Chemistry & Engineeringdoi.orgOpen source ↗.
In extended abrasion tests, commercial polyethylene-lined cups showed progressive pitting, boundary opening and flake-like surface degradation. The CNC-CA surface stayed cohesive, adherent and low-defect doi.org
ACS Sustainable Chemistry & Engineeringdoi.orgOpen source ↗. According to the university, the coating also remained stable after prolonged exposure to boiling water, food oil and a range of solvents, and it worked on lightweight paper such as brown paper towels.
Sayan Ganguly, a research associate in the Tang Nanotechnology Lab, said the coating allowed much thinner paper to be used. In his view this could cut material use and cost. The project grew out of earlier work on lightweight materials for aviation. The researchers also see uses in food packaging and other applications where companies want to replace plastics with renewable alternatives.
