Factors affecting degradation of polyethylene terephthalate (PET) during pre-flotation conditioning.
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.
Caparanga
Alvin R
AR
School of Chemical Engineering and Chemistry, Mapúa Institute of Technology, Intramuros, Manila 1002, Philippines. arcaparanga@mapua.edu.ph
Basilia
Blessie A
BA
Dagbay
Kevin B
KB
Salvacion
Jonathan W L
JW
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*
D007220:Industrial Waste; D011093:Polyethylene Terephthalates; D002245:Carbon Dioxide; C041069:carboxyl radical; D012972:Sodium Hydroxide; D017830:Octoxynol