Advances in the use of bio-based components in aqueous polyurethane dispersions for coating and adhesive applications

摘要

The use of solvent-free waterborne urethane dispersions(PUDs) is widely discussed in literature and growing across various industries due to environmental factors.The introduction of 1,3-propanediol(1,3-PDO) as a bio-based component of chain diols is accepted as shown by its use on commercial scale to produce polyester and polyether polyols.Solvent-free bio-based systems must offer all the same required properties of current commercial products with the added advantage of being eco-friendly and sustainably sourced.To obtain PUDs with good performance,the effects of varying the block components must be understood.The introduction of dimethyol propanoic acid(DMPA) pendant ionic groups into hard segment blocks facilitates the formation of stable PUDs of acceptable solids loading by increasing hydrogen bond interactions.The use of lower molecular weight bio-based polyester/polyether soft segments based on 1,3-PDO with increased hard segment blocks builds on our understanding of the structural relationships and properties in coatings and adhesives applications.The bio-based films prepared in this investigation provide an extended useful thermal range compared to reference commercial petroleum based PUDs as well as equivalent toughness and flexibility for these one-component waterborne polyurethanes.