Pecan nutshell: morphological, chemical and thermal characterization

Abstract Pecan nutshell (PNS) is generally treated as a residue or being used in low value applications. The understanding of thermal, chemical and morphologic characteristics of PNS is of great importance to determinate its application field possibilities. There are some studies for PNS applications, but none of them characterized it for polymer composites application. So, this study intends to characterize PNS focusing on polymeric composites application. PNS were characterized through morphological, chemical and thermal analysis. Degradation kinetics was performed through Flynn-Wall-Ozawa and Criado method. The results show that PNS presents a high extractive content (12.6%) and holocellulose as well (55.7%). PNS thermal degradation start at 250 °C and take place in three steps. PNS activation energy ranges from 156.25 kJ mol−1 to 264.21 kJ mol−1 and the degradation is governed by diffusion until conversion value of 0.5, when its higher multiple degradation mechanism takes place and it is not possible to determinate which one has taken place. Based on results, PNS has potential in polymer composites applications, limited to thermoplastic matrix with require a processing temperature below 220 °C.