New Article: Biobased Epoxidized Starch Wood Adhesives: Effect of Amylopectin and Amylose Content on Adhesion Properties

A new article out of Ning Yan’s lab has been published in ACS Sustainable Chemistry and Engineering written by Nicole Tratnik, Pei-Yu Kuo, Nicolas R. Tanguy, Pitchaimari Gnanasekar, and Ning Yan.
In this article studies the effect on amylopectin and amylose content in corn starches on modification through epoxidization and adhesion properties to wood

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Abstract

Formaldehyde-free, water-resistant, and environmentally friendly wood adhesives were prepared from starches via a simple one-step epoxidation reaction followed by cross-linking using diethylenetriamine. This study focused on the effect of amylose/amylopectin ratio of starch (high amylose, low amylose, and amylopectin) on the epoxidation reaction and on the bonding performance of the prepared epoxidized starches. The epoxidation of starches altered the fluid behavior of the resins, from Newtonian for pristine epoxy to shear thinning, that corroborated the successful integration of starch chains as part of the epoxy resin. Epoxidized amylopectin had the highest viscosity, 114 Pa.s, and a high degree of substitution, 2.33 ± 0.10, among the starches that indicated that amylopectin is more favorable for the grafting of epoxy groups and for the integration of starch chains in epoxy resins compared to the starches with high amylose content. Bonding strengths were determined by lap shear tests on yellow birch specimens in dry, wet, and boiled conditions. High amylopectin epoxidized starch showed the highest lap shear bonding performance under wet conditions (5.50 ± 0.451 MPa). Under boiled conditions, all three epoxidized starches showed equally better performance than the unreacted starch-filled epoxy blends. This study provides fundamental insights into the effect of starch molecular structure on epoxidation reaction and adhesion properties and suggests a promising approach for developing strong formaldehyde-free sustainable biobased wood adhesives.

New Article: Facile synthesize of phosphorus containing sustainable bio molecular platform from vanillin for the production of mechanically strong and highly flame-retardant resins

A new article out of Ning Yan’s lab has been published in ACS Sustainable Chemistry and Engineering written by Pitchaimari Gnanasekar, Martin Feng and Ning Yan

In this article a novel vanillin-based building block was used for synthesizing flame-retardant bio-based epoxy and polyurethane resins.

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Facile Synthesis of a Phosphorus-Containing Sustainable Biomolecular Platform from Vanillin for the Production of Mechanically Strong and Highly Flame-Retardant Resins Pitchaimari Gnanasekar, Martin Feng, Ning Yan*
ACS Sustainable Chem. Eng. 2020, Publication Date: November 18, 2020

Abstract

A novel chemical architecture, vanillin based phosphorus containing flame-retardant building block (VP)  was successfully synthesized as a sustainable platform biomolecule to be converted into  fire-retardant epoxy (VPE) and polyurethane (VPU) resins for application as environmentally-friendly adhesives. Structural characterizations confirmed the successful functionalization through their molecular structures. A series of VPU and VPE blends were prepared that showed excellent dry and wet bonding strengths and superior self‐extinguishing fire‐retardancy. The highest bonding strength of VPE80 for dry, cold and hot water treatment were noted about 3.64, 3.62 and 3.35 MPa respectively and the best fire‐retardant properties with the maximum LOI value of 29.6% and the lowest heat release rate according to cone calorimetry tests, due to the strong synergistic interpenetrating networks formed between the epoxy and PU macromolecules. The GC-MS analysis of the char residues indicated that the mechanisms for fire-retardancy were a combination of the quenching effect from the phosphorus-containing free radicals and the diluting effect of the non-flammable gases in the gas phase, plus the formation of phosphorus-rich char layers in the condensed phase. This study showcased a highly promising approach to develop environmentally-friendly high-performance fire-retardant chemicals using non-toxic vanillin as the starting material.

New Article: Lignin as a Key Component in Lignin-Containing Cellulose Nanofibrils for Enhancing the Performance of Polymeric Diphenylmethane Diisocyanate Wood Adhesives

A new article out of Ning Yan’s lab has been published in ACS Sustainable Chemistry + Engineering written by Heyu Chen, Pitchaimari Gnanasekar, Sandeep S. Nair, Wenbiao Xu, Prashant Chauhan, and Professor Ning Yan

In this article, lignin-containing cellulose nanofibrils (LCNFs) were used in polymeric diphenylmethane diisocyanate (pMDI) wood adhesives as a functional compound to significantly reinforce bonding properties.

For the first 12 months of publication, 50 free e-prints are available for interested colleagues.

Click here to see the article and get your free e-print.

Lignin as a Key Component in Lignin-Containing Cellulose Nanofibrils for Enhancing the Performance of Polymeric Diphenylmethane Diisocyanate Wood Adhesives Heyu Chen, Pitchaimari Gnanasekar, Sandeep S. Nair, Wenbiao Xu, Prashant Chauhan, and Ning Yan ACS Sustainable Chemistry & Engineering Article ASAP
DOI: 10.1021/acssuschemeng.0c05642

Recent article from Prof. Yan group accepted in Green Chemistry

In this article, Dr. Heyu Chen, Dr. Prashant Chauhan, and Prof. Ning Yan reported a novel strategy to effectively utilize the bark waste stream as a promising starting material to synthesize environmental-friendly polyurethanes without using hazardous isocyanate/phosgene. Full details can be found here as the Accepted Manuscript.

Barking” up the right tree: biorefinery from waste stream to cyclic carbonate with immobilization of CO2 for non-isocyanate polyurethanes, Green Chemistry, 2020, DOI: 10.1039/D0GC02285C.

Recent Papers

A new paper from the Yan lab has been published in ACS Sustainable Chemistry + Engineering titled From Wastes to Functions: A New Soybean Meal and Bark-Based Adhesive written by Jing Luo, Ying Zhou, Qiang Gao, Jianzhang Li, and Ning Yan

For the first 12 months of publication, 50 free e-prints are available for interested colleagues.

Click here to see the article and get your free e-print.

Recent Publication is Now Featured on “Advances in Engineering” as a Key Scientific Article

Advances in Engineering—which recognizes important findings in engineering fields and reports timely engineering research news—has recently labeled a research work that came from Professor Ning Yan’s group as a “key scientific article contributing to science and engineering research excellence.”

Report link: https://advanceseng.com/lignin-containing-cellulose-nanofibril-application-pmdi-wood-adhesives-drastically-improved-gap-filling-properties-robust-bondline-interfaces/

This work was done by University of Toronto researchers: Heyu Chen (PhD candidate), Dr. Sandeep Nair, Dr. Prashant Chauhan and led by distinguished professor, Prof. Ning Yan; they investigated the effect of lignin-containing nanocellulose (LCNF) on the reinforcing performance of pMDI wood adhesives. As concluded by Advances in Engineering: “Sustainable LCNF from renewable biomass will advance the development of high-performance pMDI adhesives for wider practical applications.”

For further information, this work is published in Chemical Engineering Journal.

Chen, H., Nair, S., Chauhan, P., & Yan, N. (2019). Lignin containing cellulose nanofibril application in pMDI wood adhesives for drastically improved gap-filling properties with robust bonding line interfaces. Chemical Engineering Journal, 360, 393-401.

Recent article from Dr. Tanguy accepted in ACS Applied Materials & Interfaces

In this article, Dr. Tanguy and Prof. Yan, in collaboration with M.S. Whiltshire, Prof. Arjmand and Prof. Zarifi from the University of British Columbia reported the design of novel sensors for the contactless detection of ammonia gas at concentration as low as 1 ppm.

https://pubs.acs.org/doi/abs/10.1021/acsami.9b21063

Abstract: Ammonia is a key-compound in a variety of industrial sectors, including automotive, chemical and food. Its hazardous effects on the environment and human health require the implementation of proper safety guidelines and monitoring techniques. An attractive approach is to add sensing functionality to low-cost wireless communication devices to allow for the monitoring/mapping of the chemical environment across a large area. This study outlines a highly sensitive contactless ammonia gas sensor with the potential for the continuous and wireless mapping of ammonia emissions by integrating an antenna on the device. The devices were fabricated by casting a novel advanced sensing nanocomposite, polyaniline (PANI) and phosphate functionalized reduced graphene oxide (P-rGO) on split-ring resonators (SRRs). P-rGO incorporation in PANI produced a positive sensing synergistic effect to multiply the sensing response severalfold to ammonia and dimethylamine gases. Furthermore, we identified that the modification of the semiconductive behavior of the nanosheets, achieved via phosphate functionalization, is the key factor to the positive sensing synergy observed in the nanocomposites due to the formation of localized heterojunctions. The prepared SRRs exhibited remarkably low detection limit, ~1 ppm, to ammonia gas, as well as good stability and selectivity, which paves the path for a novel generation of wireless, chipless, potentially fully printable and passive sensor platforms.