Fabrication of Food-Safe Water-Resistant Paper Coatings Using a Melamine Primer and Polysiloxane Outer Layer

Abstract

Paper-based materials are highly desirable as packaging materials due to their numerous advantages that include low cost, renewability, and biodegradability. However, their hydrophilicity has limited their range of applications. Reported herein is a facile and economical approach for the preparation of biodegradable water-resistant paper for food-contact applications. Commercial printing paper and cup papers are coated with melamine, which is FDA approved for food-contact applications. Subsequently, a water-repellent outer layer is applied using poly(dimethylsiloxane) (PDMS)–isocyanate. A relationship between the PDMS concentration and water contact angles (WCAs) of the obtained coating was studied. Typically, the coated cup paper and printing paper had coating loadings of 1.61 ± 1.10 and 0.93 ± 0.74 wt %, respectively. After the coatings had been applied, the WCAs were very high (>125°), and water absorption had decreased by 70% for printing paper and by 35% for cup paper. Considering the facile fabrication method and the low-cost food-safe raw materials, herein, this approach will have great potential for the large-scale production of materials for use in food- and nonfood contact applications.

Dual-Layer Approach toward Self-Healing and Self-Cleaning Polyurethane Thermosets

“…The IR spectra of this finished coating did not exhibit any NCO peaks at 2270 cm −1 , indicating a complete curing treatment (SCH-7). In addition, a peak appeared at 1260 cm −1 corresponding to the Si-CH 3 stretching vibration of the indicates the successful grafting of PDMS-NH 2 [40,49].…”

“…However, due to the harmful and persistent nature of fluorine-containing compounds in the environment, fluorine-free alternatives are highly desirable. In this regard, PDMS has recently been employed by our group and others to introduce self-cleaning properties [38,39,40,41,42,43,44,45]. In a recent study, polydopamine (PDA) coated fabric was treated with stearic acid to impart excellent water repellency.…”

Oil‐ and water‐resistant paper substrate using blends of chitosan‐graft‐polydimethylsiloxane and poly(vinyl alcohol)

“…The ATR-FTIR analysis, as shown in Figure 2, confirmed the grafting of PDMS in the PVOH/chitosan-g-PDMS coated paper by the presence of characteristic PDMS peaks at 1257.59 and 790.81 cm −1 which corresponds to Si CH 3 stretching and Si O Si bending vibrations in the PVOH/chitosan-g-PDMS coated paper. 11,28 Basis weight and thickness are important basic properties that highly influence the mechanical, barrier, and optical properties of the paper. 29 Therefore, selected samples were subjected to basis weight and thickness analysis as shown in Table 1.…”

“…9 To address the above challenges, our group is actively working towards developing plastic-free, PFAS-free, costeffective water-and oil-resistant surfaces. [10][11][12][13][14][15] One of the key focus is the use of benign polydimethylsiloxane (PDMS) as an alternative to PFAS because PDMS is known for imparting water and oil repellent properties while still acceptable for food contact applications. [16][17][18][19][20][21][22] In a recent breakthrough study, we reported the fabrication of water-and grease-resistant coating using Chitosan-grafted-PDMS (Chitosan-g-PDMS), and the coated paper was 100% recyclable by washing the coating off.…”

Fabrication of oil‐ and water‐resistant paper without creating microplastics on disposal

“…Polysaccharides and proteins are biodegradable in nature and their use for paper coating is very appealing, but they are hydrophilic in nature and hence they have poor water resistance 10,19–21 . Recently, our group has developed chitosan‐ graft ‐silicone oil coatings for paper with good water and oil repellent properties 22–26 . Silicone oil was chosen because of its relatively food safe nature and exceptional water and oil repellent properties that have been demonstrated in various coatings 27–34 .…”