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Polyurethane synthesis, wherein the urethane groups −NH−(C=O)−O− link the molecular units A kitchen sponge made of polyurethane foam . Polyurethane (/ ˌ p ɒ l i ˈ jʊər ə ˌ θ eɪ n,-j ʊəˈr ɛ θ eɪ n /; [1] often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links.
4,4′-Methylenebis(2-chloroaniline) (also known as MOCA, MBOCA, and bisamine) is a substance used as a curing agent in polyurethane production. [3] MOCA is an aromatic amine which is structurally similar to benzidine, a known human bladder carcinogen.
Thermoplastic polyurethane (TPU) is any of a class of polyurethane plastics with many properties, including elasticity, transparency, and resistance to oil, grease, and abrasion. Technically, they are thermoplastic elastomers consisting of linear segmented block copolymers composed of hard and soft segments.
Couches and mattresses, TVs and refrigerators, tires and toys, even clothes are full of polyurethane and plastics, which vaporize into a toxic smoke once they're set on fire, said Dr. Gina Solomon ...
A lethal dose for rats is between 150 ppm and 220 ppm, meaning the air in the building was highly toxic. On 27 January 2013, a fire at the Kiss nightclub in the city of Santa Maria, in the south of Brazil, caused the poisoning of hundreds of young people by cyanide released by the combustion of soundproofing foam made with polyurethane. By ...
Polyurethane polymers have a wide range of properties and are commercially available as foams, elastomers, and solids. Typically, polyurethane polymers are made by combining diisocyanates, e.g. toluene diisocyanate, and diols, where the carbamate groups are formed by reaction of the alcohols with the isocyanates: [12] RN=C=O + R′OH → RNHC(O ...
Ethyl carbamate is not acutely toxic to humans, as reflected by its use as a medicine. Acute toxicity studies show that the lowest fatal dose in rats, mice, and rabbits equals 1.2 g/kg or more. When ethyl carbamate was used medicinally, about 50% of the patients exhibited nausea and vomiting, and long-time use led to gastroenteric hemorrhages. [21]
From that month through January 2016, HPD issued more than 10,000 violations for dangerous lead paint conditions in units with children under 6, the age group most at risk of ingesting toxic paint. Half of the violations were in just 10 percent of the city’s zip codes, low-income neighborhoods in the Bronx, Brooklyn and northern Manhattan, a ...