title: Evidence of chemical reactions between di- and poly-glycidyl ether resins and tannins isolated from Pinus radiata D. Don bark.
abstract: This work evaluates the feasibility of reacting tannins isolated from Pinus radiata D. Don bark with epoxide resins of the diglycidyl and polyglycidyl ether type. To this end, gel times of aqueous tannin dispersions (40% w/w) with every one of nine selected resins (5% w/w), at previously established pH values (initial equal to 3.3, 4, 7 and 10), have been determined. Products of these reactions were analyzed by FT-IR spectroscopy, and the results were compared with those obtained from tannin-p-formaldehyde and (+)-catechin-p-formaldehyde systems, at the same pH values. Their mechanical properties were evaluated, by dynamic mechanical analysis, at two pH values (3.3 and 10). In general, it was concluded that tannin-epoxide resin systems behave similarly to tannin-paraformaldehyde systems, especially at basic pH values.
authors.affiliation: Renewable Resources Laboratory, Faculty of Chemical Sciences, Universidad de Concepción, Chile, P.O. Box 160-C, Concepción, Chile.
authors.forename: Roy
authors.initials: R
authors.lastname: Soto
authors.forename: Juanita
authors.initials: J
authors.lastname: Freer
authors.forename: Jaime
authors.initials: J
authors.lastname: Baeza
mesh_terms: D002392:Catechin / Q000378:metabolism; D004852:Epoxy Compounds / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D005557:Formaldehyde / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D028223:Pinus / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D012116:Resins, Plant / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D013634:Tannins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors
chemical_list: D004852:Epoxy Compounds; D010936:Plant Extracts; D012116:Resins, Plant; D013634:Tannins; C020344:glycidyl ethers; D005557:Formaldehyde; D002392:Catechin