Effect of addition of glycolysis products of poly(ethyleneterephthalate) wastes to urea-formaldehyde resin on its adhesion performance to wood substrates and formaldehyde emission
(2377–2383)Journal of Applied Polymer  Science 123 #4 (2012)
Essawy, Tawfik and Elsayed of the National Research Center, Egypt, recycled poly(ethyleneterephthalate) waste through glycolysis using diethyleneglycol (DEG) and poly(ethyleneglycol) (PEG 400).  The products of glycolysis from both cases were individually incorporated as modifiers during the synthesis of urea-formaldehyde resins from both the basic as well as acidic stages, respectively.  The free formaldehyde level was remarkably decreased for the modified resins while the gel time was slightly affecte.  In addition, the adhesion strength of wood joints bonded with the modified resins improved markedly in the dry state while the moisture resistance was significantly fortified with respect to the comparable joints formulated from unmodified resins where instant failure took place within few hours after immersion in water.  (RDC 11/2/2011)

Chemical recycling of PET flakes into yarn
(520–525)Journal of Applied Polymer  Science 123 #1 (2012)
Upasan et al of Reliance Industries Limited. India, studied the chemical recycling wherein part of the virgin raw-materials during preparation of polyester was replaced by washed post consumer polyester.  During the process, the postconsumer polyester undergoes partial depolymerization before repolymerization.  (RDC 10/12/2011)

The selective recycling of mixed plastic waste of polylactic acid and polyethylene terephthalate by control of process conditions
(1970-1976) European Polymer Journal 47  #10 (2011)
Sánchez and Collinson ofCranfield University, United Kingdom, evaluated the glycolysis of postconsumer polyethylene terephthalate (PET) waste with catalysts of zinc acetate, zinc stearate and zinc sulfate, showing that zinc acetate was the most soluble and effective.  The chemical recycling by solvolysis of polylactic acid (PLA) and PET waste in either methanol or ethanol was investigated. Zinc acetate as a catalyst was found to be necessary to yield an effective depolymerization of waste PLA giving lactate esters, while with the same reaction conditions PET remains as an unconverted solid. This provides a strategy to selectively recycle mixed plastic waste by converting one plastic to a liquid and recovering the unreacted solid plastic by filtration.  (RDC 9/20/1011)

Recycled Polyethylene Terephthalate Filled Natural Rubber Compounds: Effects of Filler Loading and Types of Matrix
(429-449) Journal of Elastomers and Plastics 43 #5 (2011)
Abstract
Nabil,  Ismail and Azura of the Universiti Sains Malaysia, Malaysia, used recycled polyethylene terephthalate (R-PET) as a filler in natural rubber (SMR L) and epoxidized natural rubber (ENR 50) compounds.  Results indicated that the maximum torque, scorch, and cure time of SMR L compounds increased with increasing R-PET loading, whereas ENR 50 compounds showed the decreasing trend in scorch and cure time.  Increment in R-PET increased crosslink density and tensile modulus of both natural rubber compounds.  Tensile strength, elongation at break, and fatigue life of both natural rubber compounds showed the decreased trend with increasing R-PET loading but ENR 50 showed the lower values than SMR L compounds.  The thermal degradation was shifted to a higher temperature and the micrographs exhibited the detachment of R-PET and more agglomeration with increasing R-PET loading in both natural rubber compounds.  (RDC 9/7/2011)

Chemical Recycling of PET Waste with Multifunctional Pentaerythrytol in the Melt State
(254-262) Journal of Polymers and the Environment 19 #1 (2011)
Mendes, Diaz and Rodrigues of the Federal University of Rio de Janeiro recycled poly(ethylene terephthalate) PET waste in the melt state through alcoholysis with multifunctional alcohol—pentaerythrytol (PENTE)—in a internal mixer Haake Rheomix 600, at 250 °C, 60 rpm, for 10 min, in presence of zinc acetate.  Esterification and alcoholysis reactions took place and were dependent on the molar ratio. The first one is dominant in compositions rich in PET leading to the formation of star-branching copolymer. The second one brings about the PET oligomerization and an oligoester named herein bis(tri-hydroxylneopentyl) terephthalate (BTHNPT) was obtained. The end-products have potential application as asphalt additive or adhesive.  (RDC 4/22/2011)

Kinetic analysis and modelling of PET macromolecular changes during its mechanical recycling by extrusion  
(236-246) Polymer Degradation and Stability 96 #2 (2011)
Nait-Ali, Colin and Bergeret, France showed that two types of oxidative macromolecular changes take place successively in an extruder reactor. Chain scissions predominate in the “strongly oxygenated” zones (at the feeder and die), whereas chain couplings (mainly chain branching) predominate in “poorly oxygenated” zones (in the middle of the reactor). Thus, it appears that the relative predominance of both types of modifications is closely related to the extruder geometry and size (in particular, the feeder and die sections and the screw length). (RDC 1/29/2011)