Relationships between the molecular structure and the flammability of polymers: Study of phosphonate functions using microscale combustion calorimeter

摘要

Introduction The objectif of the present work is to determine the relationships between the molecular structure and the flammability of phosphorus-containing polymers. Our work is based on the proposal of Lyon et al. [1-2]. In their work the contributions to two flammability parameters (heat release capacity HRC and total heat release THR) of various chemical groups were calculated. In their work, each chemical group i contributed to a given flammability parameter P according to the additive rule of mixtures: P = Φ_a* P_a + Φ_b * P_b + ... + Φ_i * P_i with Φ_a, Φ_b...Φ_i the molar fraction and P_a, P_b... P_i the specific contributions of the groups a, b... i respectively. Hundreds of polymers of known chemical compositions have been tested using microscale combustion calorimeter, and a statistical analysis provides over 40 different empirical molar group contributions to the HRC and THR. Measured and calculated flammability parameters for over 80 polymers are quite well correlated. Nevertheless, if we consider a specific polymer, the calculated values do not always match the measured ones, in particular for heat release capacity. The main reason is that interactions between the different groups present in the polymer were neglected.