Insight into the Molecular Weight of Hydrophobic Starch Laurate-Based Adhesives for Paper
Issued Date
2023-04-01
Resource Type
eISSN
20734360
Scopus ID
2-s2.0-85152860540
Journal Title
Polymers
Volume
15
Issue
7
Rights Holder(s)
SCOPUS
Bibliographic Citation
Polymers Vol.15 No.7 (2023)
Suggested Citation
Watcharakitti J., Nimnuan J., Krusong K., Nanan S., Smith S.M. Insight into the Molecular Weight of Hydrophobic Starch Laurate-Based Adhesives for Paper. Polymers Vol.15 No.7 (2023). doi:10.3390/polym15071754 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/81987
Title
Insight into the Molecular Weight of Hydrophobic Starch Laurate-Based Adhesives for Paper
Author(s)
Author's Affiliation
Other Contributor(s)
Abstract
Instead of using finite petroleum-based resources and harmful additives, starch can be used as a biodegradable, low-cost, and non-toxic ingredient for green adhesives. This work employs K3PO4 catalyzed transesterifications of cassava starch and methyl laurate at varying reaction times (1–10 h), resulting in the enhanced hydrophobicity of starch laurates. At longer reaction times, starch laurates having higher degrees of substitution (DS) were obtained. While starch laurates are the major products of transesterification, relatively low-molecular-weight byproducts (1%) were detected and could be hydrolyzed starches based on gel permeation chromatography results. Contact angle measurements confirmed the relatively high hydrophobicity of the modified starches compared with that of native starch. The modified starches were then employed to prepare water-based adhesives on paper (without any additional additives). Notably, the shear strength of the esterified starch adhesives appears to be independent of the DS of esterified samples, hence the transesterification reaction times. Additionally, the shear strength of water-based adhesives (0.67–0.73 MPa) for bonding to paper substrates is superior to that of two other commercially available glues by a factor of 10 to 80 percent.