Pyrolysis-GC and MS applied to study oligomer formation in the degradation of polystyrene and styrene copolymers

Effect of Porous and Nonporous Carbonaceous Substrates on Polystyrene Thermal Degradation during Fast CO2 Laser Heating

“…Also, styrene is known to be the most abundant product of polystyrene thermal degradation under most experimental conditions. 6,9, [12][13][14][15][16][17][18] These observations lend support to our proposed used of the styrene evolution profile to represent polystyrene thermal degradation. The thermal decomposition kinetics of polystyrene are well studied.…”

“…The thermal decomposition kinetics of polystyrene are well studied. [7][8][9]11,14,15,[17][18][19]21 In the literature, the reported apparent activation energies of decomposition range from 20 to 83 kcal/mol. 7,8,21 Using the data obtained by TG/MS an Arrhenius plot was constructed using a first-order rate law (the plot is shown in Figure 7).…”

“…To achieve these conditions, we constructed and tested the CO 2 laser pyrolysis system (shown in Figure ). − Porous (Spherocarb) and nonporous (Glassy Carbon) spherical particles were selected as the carbonaceous substrates, and polystyrene was chosen as the model polymer for these studies. Not only is polystyrene one of the most extensively studied and characterized polymers, − but also it has some degree of structural resemblance to coal in that alkylaromatic “tar” components are produced upon pyrolysis. − Hence, studying the thermal degradation behavior of polystyrene in the presence of porous and nonporous carbonaceous substrates could help shed light on the effect of porosity on the elution of similar products from coal.

1 Schematic layout of the laser pyrolysis system.

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Mechanisms of thermal degradation of polystyrene, polymethacrylonitrile, and their copolymers on flash pyrolysis

“…19,20 Contrarily, it has been reported that in the flash pyrolysis of poly(styrene) monomer units of 60 -80% were generated as monomer molecules and the remaining monomer units of 20 -40% were produced as dimer and trimer molecules. 21,22 The yields of monomer molecules regenerated from the copolymers of styrene-acrylonitrile and styrene-methylmethacrylate in flash pyrolysis differed from those of monomers produced by the pyrolysis of corresponding homopolymers under the same conditions. 3,23,24 As a first approximation, it was considered that, in the pyrolysis of the A-B copolymer, the regeneration probability of A monomer unit at the boundary of A and B sequences, P AB , differed from that in A sequence, P AA , and also the same situation was expected for B monomer units; i.e., P BA was different from P BB .…”

Estudio de la degradación de materiales compuestos base poliéster reforzados con fibra de vidrio en medios neutros y alcalinos

“…En el estudio del comportamiento de materiales compuestos expuestos a soluciones alcalinas es fundamental, no sólo la evaluación de los indicadores mecánicos y su evolución con el tiempo de exposición, sino también complementarlo con control e inspección morfológica del material [Stevens 2009], así como técnicas de análisis que ayuden a la mejor comprensión de los complejos mecanismos responsables de la degradación, con técnicas microscópicas como el AFM [Frisbie 1994, Mortaigne 1997, Raiteri 1999, Raghavan 2000, Gu 2001, Mosiewicki 2006, técnicas espectroscópicas [Dean 1989, Hiltz 1991, Regnier 1995, Raemaekers 1997 …”