(53m) Manufacturing of High-Performance Intumescent Flame-Retarded Polymer Composites

Currently, most engineering plastics used in automobiles and building constructions are highly flammable and release toxic gases and smoke during the combustion. One method to resolve flammability issue of plastics is the use of intumescent flame retardants (IFRs). However, traditional IFRs cannot suppress heat and toxic releases efficiently due to its poor dispersion in the polymer matrix.

In this work, we seek to utilize the integration of metal-organic frameworks (MOFs) with intumescent flame retardants for developing fire-safe polymer composites and it shows a promising strategy to manufacture well-dispersed and highly efficient flame-retardant polymer composites in a scalable scale. Specifically, it requires only small amounts of MOFs (low cost) and still provides significant improvements on suppressing heat release over conventional IFR polymer composites. It can also reduce toxic releases during the combustion compared to currently available IFR polymer composites due to the unique catalytic effects from the metal ions in the MOFs. An example on the development of polypropylene (PP)/IFR composites using different zeolitic imidazolate frameworks (ZIFs) is shown below. It was found that when adding 2 wt% ZIF-8, the peak heat release rate was decreased to 172.90 kW/m² compared with 298.30 kW/m² for IFR-PP and 904.98 kW/m² for neat PP. A reduction of total smoke release was observed from 2704.2 m²/m² to 1886.2 m²/m² and peak smoke production rate decreased from 0.10 m²/s to 0.045 m²/s. Another released toxic component CO production rate were also suppressed during the combustion period.