Amber heat effect

A suspension of 4 g of trans-2-(2,5-dimethoxy-4-methylphenyl)-cyclopropanecarboxylic acid in an equal volume of H20, was treated with sufficient acetone to effect complete solution. This was cooled to 0 °C and there was added, first, 2.0 g triethylamine in 35 mL acetone, followed by the slow addition of 2.5 g ethyl chloroformate in 10 mL acetone. This was stirred for 0.5 h, and then there was added a solution of 1.7 g NaN i in 6 mL If20, dropwise. After 1 h stirring at 0 °C, the mixture was quenched by pouring into H20 at 0 °C. The separated oil was extracted with EtzO, and extracts dried with anhydrous MgS04. Removal of the solvent under vacuum gave a residue of the azide, which was dissolved in 10 mL anhydrous toluene. This solution was heated on the steam bath until the nitrogen evolution was complete, and the removal of the solvent under vacuum gave a residue of crude isocyanate as an amber oil. This intermediate isocyanate was... 

The cloudiness in some amber specimens is due to the presence of many very tiny air bubbles. In an effort to produce the more commercially desirable transparent amber, this material is often cleared by heating. This has the effect of driving off the air bubbles, and may achieve a better-looking product. At the same time, however, water is also driven off, leaving a more brittle, and sometimes less lustrous material. Heating done too quickly or at too high a temperature can also result in the formation of flat ovoid structures within the amber. These flying saucers are often exploited by dealers as natural inclusions. 

F ute 1.19 Baltic amber cabaehous, showing the effects of progressive degrees of heat treatment. The palest bead is untreated. 

F ure 1.20 Baltic amber, broken bead showing sur ce effect of heat treatment. 

Uses Lt. stabilizer for PP, ABS, PS, nylon, LDPE, LLDPE, HOPE, acrylics, PC, thermoplastic polyester, SAN, thermoplastic elastomers, surf, coatings, suitable for thin films, fibers, or molded parts Features Esp. effective in polyolefins for outstanding heat and processing stability use with UV-Chek AM-340 Properties Lt. amber micro-pastille very sol. in aromatic hydrocarbons, ketones, esters, some alcohols very low sol. in aliphatic hydrocarbons and water misc. with methylene, methylene chloride m.w. > 2400 sp.gr. 1.03 bulk dens. 5.8 Ib/gal soften, pt. 100 C min. 

Properties Amber liq. mild odor sol. in most org. soivs. si. sol. in water m.w. 359.58 Toxicology LD50 (oral, rat) 9.66 mg/kg, (IV, rat) 6.6 mg/kg, (dermal, rat) 30-108 mg/kg poison by ing., skin contact, IP, subcut. and IV routes human blood system effects by skin contact a cholinesterase inhibitor Environmental Toxic to fish Precaution EPA extremely hazardous substances list corrosive to metal Hazardous Decomp. Prods. Heated to decomp., emits very toxic fumes of Cl" and POx Uses Insecticide, acaricide, nematicide, parasiticide... 

Properties Lemon to amber liq., char, odor, bitter taste sol. in water, alcohol, ethyl acetate, methanol, dioxane insol. in min. oil, min. spirits m.w. 1227.72 HLB 16.9 acid no, 0-2 sapon. no. 40-50 hyd. no. 60-108 Toxicology LD50 (oral, rat) 37 g/kg, (IV, mouse) 1420 mg/kg, (IP, rat) 3850 mg/kg mod, toxic by IP, IV route mildly toxic by ing. human skin irritant experimental teratogen, reproductive effects TSCA listed Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and irritating fumes... 

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