Abstracts Book - IMRC 2018

• SB1-P097
EFFECTS AND APPLICATIONS OF ULTRASONIC STRESS ON
POLYSTYRENE WASTE
Arturo López Pérez 1,2 , Gerardo Cedillo Valverde 1 , Salvador López Morales 1 , Miguel Ángel
Canseco 1 , Manuel García Hipólito 3 , Hermilo Zarco Garcia 4
1
Instituto de Investigaciones en Materiales, Polímeros, Mexico. 2 Universidad Nacional
Autónoma de México, Facultad De Estudios Superiores Cuautitlán, Mexico. 3 Instituto de
Investigaciones en Materiales, Materiales Metálicos Y Cerámicos, Mexico. 4 Instituto de
Investigaciones en Materiales, Materia Condensada Y Criogenia, Mexico.
Prevailing issues derived of the inadequate polymeric waste management, have
promoted in the last decades, the increase of pollution rates around the globe.
For this reason, a recycling process has been proposed, which consists, basically,
of ultrasonic irradiation at 42 kHz and 1.2 MHz, on waste Polystyrene (PS)
solutions (designated as Low Molecular Weight Polystyrene (PSLMW) and High
Molecular Weight Polystyrene (PSHMW)). Such irradiation was carried out in three
different solvents: Chloroform (CHCl3), Tetrahydrofuran (THF) and Toluene
(Tol). As a result, it could be proved that at the lower frequency, the polymeric
chains of PSLMW manifest scissions, which causes molecular weight decrease and
ipso facto, the promotion of their degradation. On the other hand, analogous
samples of PSHMW that were irradiated at the highest frequency showed the
opposite behavior since they increase the values of their molecular weight. This
suggests a mechanism where first takes place an intra-chain scission that results
subsequently in a chain rearrangement and growth of themselves. All molecular
weights and structures of the samples had been corroborated by employing
several techniques such as Viscometry, High Performance Size Exclusion
Chromatography (HPSEC) and Nuclear Magnetic Resonance ( 1 H-NMR),
respectively. Moreover, the study of thermal behavior of Polystyrene-
Polymethylmethacrylate mixtures put under the effects of Ultrasonic Stress (US),
were characterized by Thermogravimetric Analysis (TGA) and Differential
Scanning Calorimetry (DSC), where it was exhibited that Vitreous Transition
Temperature (Tg) shows intermediate behavior between those of the individual
homopolymers. These discoveries are guidelines for future industrial
applications, among which are included degradation and modification of
polymeric molecular weight, copolymerization, coatings, paints and composites
elaboration that would be created, entirely, by recycling PS waste.