La pyrolyse de poly(adipate de butylène-1,4)

Abstract

Poly(1,4-butylene adipate) (1) was pyrolyzed in a porcelain boat placed in a quartz tube heated by a furnace. Volatile products were carried out of the heated zone into traps by a flow of nitrogen. Polyester 1 was pyrolyzed both near the entrance and near the exit of the heated zone, at 500 and 700 °C with and without a vacuum. Adipic acid (2), cyclopentanone (4), and a mixture of mono (5) and diesters (6) of the monomer, dimer, and trimer, were isolated as products of the pyrolyses.The pyrolyses of 1 at 500 °C near the exit of the heated zone at atmospheric pressure gave 14% of 2, 10% of 4, 40% of 5, and 18% of 6; 5 consisted of 26% monoester of monomer and 74% monoester of dimer, whereas 6 consisted of 63% diester of monomer and 37% diester of dimer. At 700 °C, 0.2–0.3 Torr, with 1 near the entrance of the heated zone, the yield of 2 was higher (∼35%), and trimers were found in the monoesters 5 and diesters 6, along with dimers and monomers.