Thermal stability of novolak-type thermosettings made by the condensation of bark and phenol

• Published in: Polymer degradation and stability 2000-01, Vol.68 (3), p.413-418
• Main Authors: Hakkı Alma, M, Kelley, S.Steve
• Format: Article
• Language: English
• Subjects: Applied sciences; Bark; Chemical reactions and properties; Degradation; Exact sciences and technology; Novolak resin; Organic polymers; Phenol; Phenolated bark; Physicochemistry of polymers; Thermal properties
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/S0141-3910(00)00029-X

The barks of calabrian pine ( Pinus brutia) and Anatolia chestnut ( Cestanea sativa) tree species have been condensed with phenol in the presence of sulfuric acid as a catalyst at a temperature of 130°C for 1 h. The phenolated bark species obtained was cured with hexamethylenetetramine (HMTA) at 190°C for 5 min and then, some thermal properties [thermogravimetric weight changes and glass transition point ( T g)] of the cured phenolated barks were investigated by using thermal gravimetric analysis (TGA) and differential scanning calorimetric (DSC) methods as a function of the catalyst concentrations. The results showed that themogravimetric weight losses and glass transition points ( T g) of the cured phenolated bark decreased with increasing catalyst concentration. The thermogravimetric weight loss of the cured phenolated barks was found to be comparable to those of cured commercial novolak resin and phenolated wood. Furthermore, the T gs of the phenolated bark samples were found to increase with increasing catalyst concentration and to be obviously lower than those of commercial novolak resin.