Grantee Research Project Results
Final Report: Planet-friendly and scalable approach towards 100% recyclable water- and oil-resistant paper
EPA Grant Number: SU839830Title: Planet-friendly and scalable approach towards 100% recyclable water- and oil-resistant paper
Investigators: Rabnawaz, Muhammad
Institution: Michigan State University
EPA Project Officer: Page, Angela
Phase: I
Project Period: October 1, 2019 through September 30, 2020 (Extended to July 30, 2021)
Project Amount: $24,947
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2019) RFA Text | Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Chemical Safety
Objective:
This research was aimed to develop a planet-friendly and scalable approach to fabricate 100% recyclable water- and oil-resistant paper coatings. After use, the paper pulp can be readily separated from the coating materials and thus rendered recyclable via a simple pulp washing process. Our research team used reversibly attached water- and oil-resistant coatings made of polyvinyl alcohol/chitosan-graft-polydimethylsiloxane (PVOH/chitosan-g-PDMS) to coat paper substrates. Chitosan and PVOH migrate to the paper pores and mask them, while low surface energy PDMS enriches the surface to render that surface water-, oil-, and grease-resistant. This work offers a multitude of benefits, including: i) mitigation of microplastics originating from the disposal of packaging products made of plastic or plastic-coated paper, ii) elimination of the flow of harmful per- and polyfluoroalkyl substances (PFAS) from paper coating applications, and iii) a reduction of pulp loss and the minimization of damage to the environment and ecosystems.
Objectives: The above goal of this project were achieved via the following two specific objectives:
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Objective 1 involved the fabrication of water- and grease-resistant paper coatings using PVOH/chitosan-g-PDMS, and the evaluation of their performance, such as water- and oil resistance, as well as tensile and rigidity properties.
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Objective 2 involved investigations on the recyclability of pulp derived from the PVOH/chitosan-g-PDMS-coated paper.
Conclusions:
Low-cost PVOH was added into relatively expensive chitosan-g-PDMS to yield a waterborne solution. This solution was applied to unbleached kraft paper substrates as a waterborne coating. The coated paper was subsequently subjected to performance analysis (e.g., water- and grease-resistance measurements). The microscopic analysis confirmed the successful masking of the papers’ pores by the coating. The minimum water absorptivity obtained was 20±2.1 g/m2 for paper coated with a blend of 80wt% PVOH and 20wt% chitosan-g-PDMS, which showed an improvement of almost 70% in comparison with the unmodified paper. The coated paper exhibited a maximum kit rating (oil repellency) of 7.6/12, which suggests that it possessed average oil repellency. The coating was also successfully extracted, and the pulp was recycled via washing with water. In summary, the addition of PVOH makes our paper coating approach more commercially viable as PVOH ($2-3/kg) is only ~10% of the cost of chitosan (~$20/kg). Thus, we have successfully achieved the milestones set for this EPA Phase I study, and this work was published in the Journal of Applied Polymer Science.
Both the water and oil resistance of the PVOH/chitosan-g-PDMS coatings were average only, which limits their suitability for single-use packaging applications to only less demanding water and oil resistant applications. Therefore, we went beyond the initial scope of the Phase I work (e.g., coating with PVOH/chitosan-g-PDMS) and tested starch as a potential replacement for PVOH. Starch, which is 2-4-fold cheaper than PVOH, was successfully blended with chitosan-g-PDMS and coated onto paper substrates. The starch/chitosan-g-PDMS-coated papers showed a ~82% decrease in water absorptivity (Cobb60 value: 13 g/m2, which was better than those of PVOH/chitosan-g-PDMS-coated samples) and a kit value of 12/12 (drastically improved from that achieved with PVOH/chitosan-g-PDMS coatings). This significant improvement in water- and grease-resistant properties is attributed to the starch/chitosan-g-PDMS coating’s ability to mask the pores of the unmodified paper better than the other PVOH counterpart, as was confirmed via SEM studies. In addition, the mechanical properties of the starch/chitosan-g-PDMS-coated paper were also improved, thus making it suitable for practical applications. Furthermore, the repulping tests of starch/chitosan-g-PDMS-coated paper confirmed that the coating could be successfully extracted from the paper, thus ensuring that these coated papers are completely recyclable. This coating approach employing starch/chitosan-g-PDMS also offers ~ 20-fold cheaper coating than is provided by chitosan-g-PDMS alone while still imparting excellent grease resistance and moderate to good water properties. The results obtained from starch/chitosan-g-PDMS are published in the journal of Nano Select.
References:
Sustainable Materials Group, Rabnawaz
Muhammad Rabnawaz Google Scholar
Journal Articles on this Report : 2 Displayed | Download in RIS Format
Other project views: | All 6 publications | 2 publications in selected types | All 2 journal articles |
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Type | Citation | ||
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Nair A, Kansal D, Khan A, Rabnawaz M. Oil‐and water‐resistant paper substrate using blends of chitosan‐graft‐polydimethylsiloxane and poly (vinyl alcohol). Journal of Applied Polymer Science 2021;138(21):50494. |
SU839830 (2020) SU839830 (Final) |
Exit Exit |
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Nair A, Kansal D, Khan A, Rabnawaz M. New alternatives to single‐use plastics:Starch and chitosan‐graft‐polydimethylsiloxane‐coated paper for water‐and oil‐resistant applications. Nano Select 2021. |
SU839830 (Final) |
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Supplemental Keywords:
Packaging, PFAS-free, Sustainability, MicroplasticsProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.