REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

PhosphorYLATED KRAFT LIGNIN BASED FLAME RETARDANT: efficient METHOD for improvement of lignin flame Retardancy AND MECHANICAL ACTION in POLYESTER

Jelena Rusmirović

Military Technical Institute, Belgrade, jrusmirovic@tmf.bg.ac.rs

DUNJA DANIČIĆ

Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, danicic.dunja@gmail.com

Tihomir Kovačević

Military Technical Institute, Belgrade, tkovacevic@tmf.bg.ac.rs

Marica Bogosavljević

Military Technical Institute, Belgrade, marica.radusinovic@gmail.com

saša brzić

Military Technical Institute, Belgrade, sasabrzic@gmail.com

aleksandar marinković

Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, marinko@tmf.bg.ac.rs

tatjana stevanović

Département des sciences du bois et de la forêt, Université Laval, Québec, Canada Tatjana.stevanovic@sbf.ulaval.ca

Abstract: In this paper, the potential application of phosphorylated industrial kraft lignin (KLP) in improving flame retardant properties of unsaturated polyester/KLP composites (UPe/KLP) was studied. KLP mass contents in UPe based composites varied from 0.5 wt.% to 5.0 wt.%. The successfulness of the performed phosphorylation method, direct grafting of phosphorus chloride on KLP surface hydroxyl groups, and formation of phosphoric acid ester were confirmed via Fourier Transform-Infrared Spectroscopy (FT-IR). The effects of KLP surface functionalization and KLP mass contents on the UPe tensile properties were studied. Tensile strength (σ), elongation (ε) and Young’s modulus of elasticity (E) of the UPe/KLP composites were analyzed in relation to the structure of KLP modification. The obtained composites were tested on fire retardant properties according to the standard test method UL-94V.

Keywords: Lignin modification; fireproof lignin composites; tensile testing; flame retardancy.