title: Factors affecting degradation of polyethylene terephthalate (PET) during pre-flotation conditioning.
abstract: In general, plastics are exposed to different degrading agents in every procedure involved in their recovery from waste mixture and from subsequent recycling. In this study, two methods of pre-flotation conditioning were used to determine how these methods affect the general properties of the pre-conditioned PET particles to be recovered from the PET-PVC mixture. The first method comprised the conditioning of PET samples using an alkaline solution of nonionic surfactant (Triton X-100) based on the patent by the Goodyear Tire and Rubber Company. The second method, developed in this study, was a conditioning process which used an alkali-less solution of the same nonionic surfactant (Triton X-100) used in the first method. The following analytical methods were used to characterize properties of the pre-conditioned PET samples that were correlated to relative degradation of the samples: differential scanning calorimetry (DSC), for thermal behavior of the samples; FT-IR spectroscopy, for functional groups present in the samples; and, Pohl's method, for carboxyl end-group concentration count. Results show that in addition to water the presence of NaOH in the conditioning solution contributes to the further degradation of the polymer.
authors.affiliation: School of Chemical Engineering and Chemistry, Mapúa Institute of Technology, Intramuros, Manila 1002, Philippines. arcaparanga@mapua.edu.ph
authors.forename: Alvin R
authors.initials: AR
authors.lastname: Caparanga
authors.forename: Blessie A
authors.initials: BA
authors.lastname: Basilia
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Dagbay
authors.forename: Jonathan W L
authors.initials: JW
authors.lastname: Salvacion
mesh_terms: D002152:Calorimetry, Differential Scanning; D002245:Carbon Dioxide / Q000032:analysis; D006868:Hydrolysis; D007220:Industrial Waste; D017830:Octoxynol / Q000737:chemistry; D011093:Polyethylene Terephthalates / Q000737:chemistry / Q000302:isolation & purification*; D012972:Sodium Hydroxide / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D018505:Waste Management / Q000379:methods*
chemical_list: D007220:Industrial Waste; D011093:Polyethylene Terephthalates; D002245:Carbon Dioxide; C041069:carboxyl radical; D012972:Sodium Hydroxide; D017830:Octoxynol