Determination of the structure and composition of clinically important polyurethanes by mass spectrometric techniques

Curie‐point pyrolysis mass spectrometry (Py‐MS) and direct probe pyrolysis high resolution mass spectrometry (Py‐HRMS) were used to identify the components and additives used in the synthesis and compounding of Biomer, Lycra Spandex, Tecoflex, and Pellethane. Two types of Biomer were identified (P and Q, our notation) which are composed of poly(tetramethylene glycol) (PTMG) capped with 4,4′‐methylenebis(phenylisocyanate) (MDI) and chain‐extended with ethylenediamine (EDA). Both forms contain 4,4′‐butylidene‐bis‐(6‐t‐butyl‐m‐cresol) antioxidant, and Biomer Q also contains an additive which appears to be a quaternary ammonium chloride salt. Lycra Spandex was found to be identical to Biomer Q, with the exception that a low molecular weight polydimethylsiloxane oil is also present. This silicone oil can be removed by solvent extraction. Tecoflex (type SG80A) is composed of PTMG capped with 4,4′‐diisocyanatodicyclohexylmethane and extended with 1,4‐butanediol (BD). An industrial grade and a medical grade of Pellethane were analyzed. Both were composed of PTMG capped with MDI and extended with 1,4‐butanediol. the industrial grade also contains an antioxidant, possibly butylated diphenylamine.