Zein and PVOH-Based Bilayer Approach for Plastic-Free, Repulpable and Biodegradable Oil- and Water-Resistant Paper as a Replacement for Single-Use Plastics

Abstract

Biodegradable coated paper materials represent one of the most promising alternatives to petroleum-based materials, including plastics and plastic−paper composite materials. Herein, fully biodegradable and food-safe coated paper substrates are reported with excellent water-and oil-resistant properties. The fabrication approach is facile and economical and utilizes a dual-layer coating that is obtained via the application of a base layer comprising polyvinyl alcohol to offer oil repellency and the subsequent application of a zein-based coating as a hydrophobic top layer. The water and oil resistances of the obtained coated paper were evaluated based on their Cobb60 values, water vapor transmission rate, kit rating, and contact angles. The obtained coated paper shows outstanding water-and oil-resistant performance with Cobb60 values below 3.00 g/m 2 and kit ratings reaching up to 12/12. Scanning electron microscopy results validated the absence of any pores on the coated paper. Thermogravimetric analysis was performed to determine the thermal stability along with the coating content of the paper substrate. The closed-loop nature of this approach was validated via pulp recovery from coated paper with benign solvents.

A Proteomic Approach to Identify Zein Proteins upon Eco-Friendly Ultrasound-Based Extraction

“…Zein proteins have found wide applications as excipients in the production of inks [ 9 ], adhesives [ 10 ], water resistant paper coating [ 11 , 12 ], plastic-free replacement [ 13 ], encapsulated foods [ 14 ], and a controlled release matrix of active medical components [ 15 , 16 , 17 , 18 ]. Moreover, among various protein sources, zein (the primary storage protein in corn endosperm) has been extensively studied for its capacity to create innovative polymeric films, a feature we want to explore in the future [ 19 , 20 , 21 ].…”

Oxygen and water vapor barrier properties of polyvinyl alcohol and zein bilayer‐coated paper

“…PVOH and zein bilayer-coated paper was prepared via our recently reported approach (See Figure 1(a)). 13 In particular, PVOH is applied as the first layer onto a paper substrate and then zein is applied as the top layer. Three different types of paper substrates were studied, including bleached kraft paper (12 pt, with a thickness of 4.23 mm, unbleached kraft paper (UnBK), and bleached kraft paper (18 pt, with a thickness of 6.34 mm, Figure 1(b)).…”

“…6,11 Our group has been active in developing water and oil repellent coated paper as an alternative to plastics. 7,[12][13][14] Recently, we reported polyvinyl alcohol (PVOH)-and zein bilayer-coated paper with good water and grease resistance. 13 PVOH is a biodegradable synthetic polymer, while zein is a biodegradable material that is extracted from corn during bioethanol production.…”

“…7,[12][13][14] Recently, we reported polyvinyl alcohol (PVOH)-and zein bilayer-coated paper with good water and grease resistance. 13 PVOH is a biodegradable synthetic polymer, while zein is a biodegradable material that is extracted from corn during bioethanol production. Currently the cost of PVOH is 2-3 USD/kg, while that of zein is 20 USD/kg.…”

Sustainable and Repulpable Barrier Coatings for Fiber-Based Materials for Food Packaging: A Review

“…Recently, a bipartisan bill has been introduced to ban PFAS in the United States, and at least seven states have adopted a law to ban it in food packaging applications. Therefore, alternative bio-based, bio-degradable, and compostable organic or inorganic hydrophobic coating materials have been widely researched, which can allow either repulpability or promote compostability (Shankar and Rhim, 2018;Hamdani et al, 2020;Kansal et al, 2020;Nechita and Roman, 2020;Xiong et al, 2020;Glenn et al, 2021). Such coatings can promote the circular economy and reduce the landfill burden and environmental contamination.…”