Polyhydroxyurethanes (PHUs) Derived from Diphenolic Acid and Carbon Dioxide and Their Application in Solvent- and Water-Borne PHU Coatings

Abstract

To develop biobased polyurethanes (PUs) via a less hazardous, nonisocyanate route, herein we synthesize a series of biobased polyhydroxyurethanes (PHUs) by reacting a new biobased cyclocarbonate (derived from renewable diphenolic acid and carbon dioxide) with ethylenediamine (EDA), diethylenetriamine (DETA), and isophoronediamine (IPDA), corresponding to PHU-EDA, PHU-DETA, and PHU-IPDA, respectively. Their molecular structures are identified from 1H NMR and FTIR analyses. Gel permeation chromatography (GPC) analysis shows that the molecular weights of these PHUs grow to as high as 5 kDa in a short reaction time (4 h) at a relatively low reaction temperature (80 °C). Subsequently, the solvent-borne (in acetone) coatings of these PHUs are successfully fabricated with diglycidyl ether of bisphenol A as the cross-linker. The cured PHU coatings on aluminum panels show the high pencil hardness (up to 4 H), adhesive force (up to grade 1), glass transition as high as 116 °C, and initial thermal degradation temperature up to 190 °C. Furthermore, we realize the good dispersion of these PHUs in water by introducing chemically bonded carboxylic anions into the molecular backbone to form a stable aqueous emulsion with well-controlled particle sizes and further demonstrate its application in a water-borne PHU coating with good mechanical and thermal properties. Overall, we develop a facile yet effective method to prepare sustainable, biobased PHUs based on diphenolic acid and carbon dioxide via a safer, greener nonisocyanate route and furthermore demonstrated their use as solvent-borne coatings and greener water-borne coatings of reduced environmental impact.

Polymers Based on Cyclic Carbonates as Trait d'Union Between Polymer Chemistry and Sustainable CO2 Utilization

“…Finally,c arbonation was carriedo ut in DMF at 80 8Cw ith 20 bar CO 2 ,u sing LiBr as catalystf or 24 h( Scheme 14). [152] 4u, which is analogoust o4a,w as preparedf rom diphenolic acid (DPA), ad erivativeo fc ellulose-based levulinic acid, [153] and phenol.W hereas phenol is generally derived from oil by the cumene process, its synthesis from the pyrolysiso fl ignocellulosic biomass is possible. [150] Sinapyl alcohol, an aturallyo ccurring compound, was converted into syringaresinol (SR) by a biocatalytic oxidative coupling using laccase (Scheme 14).…”

“…Water-resistant coatings are of crucial importance for applications as filter membranes, materials for automotives, and PHU-4u-EDAcopolymer of 4u and EDA (1:1 molar ratio) cured with BPA-epoxy resin in acetone adhesion gradeA l: "grade 1" [d] [152] P(VDF-co-MAF-SiO 1.5 )c opolymer of VDF and 2h cured with APTES and hydrolyzed at the siloxane group adhesion grade (tapet est) [e] steel:"grade0 " [80] [a] Name of the polymer as given in the original manuscript. [b] [192] Polysiloxanes carrying pendantc arbonate groups were subjected to aminolysis with structurally different diaminess uch as IPDA, 4,4'-diaminodicyclohexylmethane (PACM), 1,2-propylenediamine (PDA), and HMDA to form PHU coatings.…”

“…[151] Another approach to ap otentially renewable, rigid aromatic bis-5CCf or PHU synthesis was reportedb yM ae tal. [152] 4u, which is analogoust o4a,w as preparedf rom diphenolic acid (DPA), ad erivativeo fc ellulose-based levulinic acid, [153] and phenol.W hereas phenol is generally derived from oil by the cumene process, its synthesis from the pyrolysiso fl ignocellulosic biomass is possible. [154] 4u was prepared in moderate yields from its diglycidyl ether precursor by cycloaddition reaction with CO 2 under harsh conditions (120 8C, 50 bar,i nT HF) catalyzed by DMCC/CTAB (Scheme 15).…”

“…[182] Ma et al copolymerized bio-based 4u with ethylenediamine (EDA), diethylenetriamine (DETA), and isophoronediamine (IPDA) to produce PHU-4u-EDA, PHU-4u-DETA, and PHU-4u-IPDA, respectively. [152] The PHUs were then coated on aluminum panelsi na cetonew ith BPAe poxy resin as ac ross-linker (epoxide/secondary amino groups molar ratio 1:1). AFM images showed very low roughness( < 5nm).…”

Lignin‐Based Polyurethane: Recent Advances and Future Perspectives

“…[ 11 ] Fan and Wan modified biomass biphenolic acid with epichlorohydrin, then reacted it with carbon dioxide to obtain bio‐based cyclo‐carbonate, followed by a reaction with a polyamine to obtain polyhydroxy urethane that can be used as a solvent‐ and water‐borne coating. [ 12 ] Although the preparation of polyurethane without isocyanate is desirable from environmental standpoint, the technology is still immature and high cost and needs more development.…”