词条 | Polypropylene polybenzyl isocyanate |
释义 | {{multiple issues|{{Unreferenced|date=May 2010}}{{Orphan|date=February 2009}} }} Polypropylene polybenzyl isocyanate, or PPI, is a polyurea-based polymer derived from isocyanate monomers that is used in some glues, aerosol foams, plastics, paint and household products. PPI is listed as a "hazardous agent" by the National Institutes of Health because it irritates skin and breathing passages at high concentrations. Some painters exposed to PPI and related isocyanate chemicals have developed occupational asthma. In chronic toxicity tests, mice exposed to low levels of PPI developed no side effects. Only those mice exposed to two highest concentrations developed any lung symptoms. The two highest doses used in this study were 1.0 and 6.0 mg per cubic meter for 6 hours each day, 5 days each week for 2 years. The duration-adjusted exposure levels for these two high concentrations are equivalent to 11 ppb and 70 ppb, 24 hours/day for two years. {{DEFAULTSORT:Polypropylene Polybenzyl Isocyanate}}{{polymer-stub}} 1 : Organic polymers |
随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。