Publicly available video recordings of the explosion in Beirut on August 4, 2020, were examined and from them it was possible, in conjunction with the well‐known Google Maps website, to obtain estimates for the locations of the observers’ cameras with respect to the blast, and estimates for the blast wave arrival time. A publicly‐available blast wave calculator was then used to estimate the size of the explosion in terms of the equivalent quantity of TNT that would produce the same blast wave arrival time at the observers’ distance. This work estimates the Beirut explosion to have been equivalent to 637 tons TNT, with a lower bound estimate of 407 tons and an upper bound estimate of 936 tons.

Isocyanates are highly reactive and toxic substances with severe health effects. Certain diisocyanates are restricted under REACH -The European Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals. Triethyleneglycol diglycidyl ether (TEGDGE) was used as an alternative to toxic isocyanates for the cross-linking of hydroxyl-terminated pre-polymers at 70 8C. The effect of three curing accelerators was determined while following the reaction kinetics by 1 H-NMR spectroscopy and differential scanning calorimetry (DSC). Polybutadiene (Poly BD R45HT-LO) and acrylic ester (HyTemp 4454) successfully cross-linked in 7-10 days to produce thermally stable net-works with low glass transition temperatures, as observed by DSC. Pre-aging the polybutadiene resin promoted crosslinking with TEGDGE. Four energetic compositions were then prepared using cyclotrimethylenetrinitramine (RDX) and pentaerythritoltetranitrate (PETN) as fillers, and polybutadiene (Poly BD R45HT-LO) and acrylic ester (HyTemp 4454) as binders. Both binders successfully cross-linked with TEGDGE in the presence of RDX and PETN, but only PETN was found to be chemically compatible with the crosslinked polymers. These results show that TEGDGE is suitable as a replacement for toxic isocyanates for the cross-linking of hydroxyl-terminated polyols.

Crystalline polymers such as b-cyclodextrin( bCD) can be modified with polyethylene glycol (PEG) diglycidyl ether cross-linkers (262, 394, 500 Da). In this work, the authors show that the quantity and length of the PEG soft segments influencet he solubility and malleability of the products, which are water soluble and easily converted to nitrated analoguesu nder standard reaction conditions. Inert and nitrated derivatives containing longer PEG segmentsshowed the ability to self-heal. The degree of cross-linking and de-composition temperatures ande nergies dependedo nt he quantity andl ength of the soft segment. Nitrated crosslinked bCD containingl ongerP EG segmentsd id not ignite following an electrostatic discharge of 4.5 J. The chemical stabilityo fbCD/PEG bindersw as testedb yh eat flow calorimetry at 80 8C. The balanced incorporation of soft PEG and rigid bCD segmentsw as found to improve the processability of cross-linked bCDsa nd desensitised their nitratedd erivatives, offering new solutions for inert and energetic binders.