Intumescence: Tradition versus novelty. A comprehensive review

Fire is a serious threat to people and the structures they build. There is a continuous development of newer methods and materials to prevent its effects on them. Nowadays, a lot of attention is being paid in the design of public and commercial buildings by incorporating fire safety. Passive fireproofing of high-rise structures has become very important due to the use of steel in load bearing mode and has attracted increased attention after the collapse of the WTC towers. Conventional passive fireproofing materials include concrete covering, gypsum board and cementitious coatings which have a poor aesthetic. Intumescent fire-resistive coatings are a newer type of passive fireproofing coatings usually applied as thin film and they swell many times their original thickness forming an insulating char which acts as a barrier between the fire and the structural steel. It prevents the temperatures of the steel members from reaching a critical value and helps in maintaining the integrity of the structure in fire event. They are the preferred choice for passive fire protection of load bearing steel frame structures of architects and designers as they offer aesthetic appearance, flexibility, speed of application, and ease of inspection and maintenance. The present review covers recent developments in the field of intumescent coatings with a major emphasis on organic intumescent coatings. The role of various ingredients, their interactions in intumescent coatings, effects of various pigments, binders and additives are discussed briefly.

https://link.springer.com/content/pdf/10.1007%2Fs11998-016-9815-3.pdf

Intumescent coatings: A review on recent progress

The novel application of chitosan: Effects of cross-linked chitosan on the fire performance of thermoplastic polyurethane

The paper compares the flammability and degradation performance of polypropylene (PP)/kenaf fibre composites under three different intumescent ammonium polyphosphate (APP) flame retardants. Intermeshing co-rotating twin screw extruder melt mixing approach was used to prepare the composites. The initial morphological analysis reveals that twin screw melt compounding has provided an effective homogeneous dispersion and distribution of particles, irrespective of their different particle sizes and surface energies. The thermogravimetry analysis (TGA) proves that the presence of intumescent coating of APP1 improves the thermal stability and decomposition temperature over the others. UL-94V tests and cone calorimeter analysis show that the amount of APP content and the high aspect ratio of the particles are the key factors in obtaining homogeneous flame retardant blend, which tends to decrease sustained combustion and reduce the peak heat release rates of the composites. Morphological analysis of char residue further proves that the cross-linking density of the char provides better insulation for underlying material even though the initial swelling increases the degradation temperature through pronounced blanketing effect. Further analysis using different APP particles recorded competitive mechanical properties.

Hongqiang Qi

Papers

Synergistic effect between a novel triazine charring agent and ammonium polyphosphate on flame retardancy and thermal behavior of polypropylene

Synergistic effect of zinc hydroxystannate with intumescent flame-retardants on fire retardancy and thermal behavior of polypropylene