2 2 4 trimethyl hexamethylene diisocyanate

All chemicals were purchased from Sigma Aldrich and used without modification or cleaning, unless otherwise stated. N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine (HPED, 99%), triethanolamine (TEA, 98%, Alfa Aesar), and 2,2,4-trimethyl hexamethylene diisocyanate (TMHDI, TCI America, a mixture of 2,2,4 and 2,4,4 monomers) were used as monomers. Ethyl isocyanate (98%, Sigma) was used for confirming urethane syntheformation. Fluorescent monomers, shown in Figure 1, PhB (99%), Eos (99%), IcG (95%), and Cal (99%) (Chem-Impex Int’l Inc.) were identified as having functional groups that react with isocyanate groups similarly to alcohol groups, and were added without modification. All reactive monomers are shown in Figure 1. The additives barium sulphate (BaSO_4, particle size of 3 μm, 99%), zirconium oxide (ZrO₂, particle size of 5 μm, 99%), and tungsten (W, particle size > 1 μm, 99.95%, Alfa Aesar) were used without modification.

N,N,N’,N’-tetrakis(2-hydroxypropyl)ethylenediamine (HPED, 99%), triethanolamine (TEA, 98%, Alfa Aesar), glycerol (Gly, Sigma Aldrich, 99%) and 2,2,4-trimethyl Hexamethylene diisocyanate (TMHDI, 98%, TCI America, a mixture of 2,2,4 and 2,4,4 monomers) were used as monomers. Hexamethylene diisocyanate (HDI, 98%) and isophorone diisocyanate (IPDI, 98%) were also purchased from Sigma Aldrich and were used without modification. Deuterated chloroform (CDCl₃), ethyl isocyanate (EtNCO, 98%), ethanol (190 proof), cobalt chloride anhydride (CoCl2), hydrogen peroxide (50% v/v), methanol (LCMS grade), and acetonitrile (LCMS grade) were obtained from Sigma Aldrich and used without further modification.