Reaction products of styrene-butadiene ABA block copolymer in supercritical toluene and tetralin

Reactions at supercritical conditions: Applications and fundamentals

“…They also showed that secondary reactions that form polycondensates are remarkably suppressed relative to pyrolytic depolymerization of the same materials. Dhawan et al (1991Dhawan et al ( , 1993 identified over 100 different products in their depolymerization reactions, and many of these arose from reactions of the polymer with the SCF solvents used in their studies.…”

“…The attractive features of SCFs for coal and biomass processing also motivated research into using SCFs in polymer decomposition. Dhawan et al (1991Dhawan et al ( , 1993 investigated the thermolysis of a styrene-butadiene copolymer in SC toluene and tetralin and the thermolysis of cispolyisoprene and scrap rubber in SC toluene. They also reported results from the reaction of SC toluene, tetralin, and their mixtures.…”

Degradation of polycaprolactone in supercritical fluids

“…For example, the supercritical degradation of polystyrene resulted in reducing the gas and residue products to less than 4% while the total conversion was 95% within 30 min [20]. Thus the use of a supercritical solvent as the reaction media provides an alternative approach to lower the operating temperature of the pyrolysis reactions, results in improved yields and selectivities [19]. Most importantly, the degradation rates are increased significantly when the solvent is in supercritical state, as observed for the degradation of polycarbonate [16], polystyrene [17,20] and poly(n-acrylates) To the best of our knowledge this is the first study that examines the degradation of PCL in supercritical and subcritical fluids.…”

“…The degradation rate depends on various factors like heating rate and reactor geometry. Further, polymers in the melt have high viscosity impeding mass and heat transfer [19,20]. Solvent addition results in the degradation occurring in a single phase, enhances these transfer rates, reduces the operating temperatures and often leads to higher yield with better control of the products [20].…”

“…Supercritical fluids have been used for the degradation of polycarbonate [16], polystyrene [17], poly(ethylene terephthalate) [18], styrene-butadiene [19], waste polystyrene [20] and poly(n-acrylates) [21]. Supercritical water also has been used for degradation of polymers like polystyrene [22], polyethylene [23].…”