# Study of the Influence of Melamine and Expanded Graphite on Selected Properties of Polyurethane Foams Based on Uracil Derivatives

## TL;DR

This study explores how melamine and expanded graphite affect the flammability and properties of polyurethane foams containing uracil derivatives.

## Contribution

The novel contribution is the evaluation of halogen-free flame retardants in foams with a 1,3-pyrimidine ring to improve fire safety without compromising other properties.

## Key findings

- Melamine and expanded graphite significantly reduce foam flammability.
- Expanded graphite performs better as a flame retardant without degrading foam properties.
- The resulting foams achieve a V-0 flammability class with an oxygen index of 24.9–29.5 vol.%.

## Abstract

Polyurethane foams containing heterocyclic rings are characterized by high thermal resistance, but unfortunately, they are flammable. This work examined the effect of halogen-free flame retardants such as melamine and expanded graphite: EG 096 and EG 290 on the properties of foams with a 1,3-pyrimidine ring. Oligoetherol obtained from 6-aminouracil, ethylene carbonate, and propylene oxide was foamed with polymeric diphenylmethane 4,4′-diisocyanate with the addition of flame retardants. The oxygen index was determined, and flammability tests were conducted on the resulting foams. Their apparent density, water absorption, thermal resistance, thermal conductivity coefficient, and compressive strength were also examined. Both melamine and expanded graphite significantly reduce the flammability of foams. The resulting foams are classified as V-0 flammability class, and their oxygen index is in the range of 24.9–29.5 vol.%. Expanded graphite is a better flame retardant and does not cause deterioration of other foam properties.