Thermal degradation and flammability of low ignition propensity cigarette paper

• Thermal degradation and flammability of LIP cigarette paper were investigated.
• Many closely packed particles are still present on the surface of CB in the whole temperature range.
• Main organic groups of CB displayed a slower degradation than those of OA.
• CB showed less emission of many gas products and earlier release of alkanes, CO, carbonyl compounds and alcohols than OA.
• CB exhibited lower PHRR and THR above 270 °C than OA.

The thermal degradation and flammability of ordinary area (OA) and coating band (CB) of low ignition propensity (LIP) cigarette paper were compared using scanning electron microscopy (SEM), real-time Fourier transform infrared (RT-FTIR), thermogravimetric/Fourier transform infrared spectrometry (TG-FTIR) and microscale combustion calorimeter (MCC), respectively. SEM results showed that only the compactly packed particles, instead of fibers exposed on the surface of OA, could be seen on the surface of CB. And it is at the whole temperature range that there are still many closely packed particles on the surface of CB. The results of thermal degradation displayed that CH and CO bonds in CB displayed higher thermal stabilities than those in OA. And the comparison of the evolution of their gaseous products manifested that the emission of many gas products of CB like methane, hydrocarbons, aldehydes, CO and alcohols were obviously lower than those of OA. Furthermore, some evaporated species like alkanes, CO, carbonyl compounds and alcohols escaped earlier than those of OA. Their flammability results demonstrated that both peak heat release rate (PHRR) and total heat release (THR) of CB above 270 °C in the degradation step of cellulose and the following char decomposition were lower than those of OA.