Properties and morphology of recycled poly(ethylene terephthalate)/bisphenol a polycarbonate/poly(styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene) blends by low‐temperature solid‐state extrusion

Abstract

Among the various methods available for recycling plastics waste, blending technology is a straightforward and relatively simple method for recycling. In this paper, a new blending technology, low-temperature solid-state extrusion, was discussed. Several recycled poly(terephthalate ethylene)/ bisphenol a polycarbonate/poly(styrene-b-(ethylene-co-butylene)-b-styrene) blends (R-PET/PC/ SEBS blends) have been prepared by this technology. The results show that thermal and hydrolytic degradation of R-PET is improved when extruding temperature was between the glass transition temperature (T g ) and cold crystallization temperature (T cc ). Elongation at break and notched impact strength were increased evidently, from 15.9% to 103.6, and from 8.6 kJ/m 2 to 20.4 kJ/m 2 , respectively. The appropriate rotating speed of screws was between 100 and 150 rpm. At the same time, the appropriate rotating speed of the screws brings a suitable shear viscosity ratio of R-PET and PC, which is of advantage to blending of R-PET and PC together with SEBS. Dispersion of minor phase, PC and SEBS, became finer and smaller, to about 1 mm. Chain extender, Methylenediphenyl diisocyanate (MDI) can react with the end-carboxyl group and end-hydroxyl group of R-PET. FT-IR spectra testified that the reactions have been happened in the extruding process. A chain extending reaction not only increased the molecular weight of PET and PC, but also can synthesize PET-g-PC copolymer to act as a reactive compatilizer. An SEM micrograph shows that a micro-fiber structure of PET was formed in the blend sample.

Tinctorial Response of Recycled PET Fibers to Chemical Modifications during Saponification and Aminolysis Reactions

“…T g depends on the heating rate, on the sample thermal history, and on any molecular parameter that can affect chain mobility. , The data from Table indicate that the values of T g for recycled PET samples range between 76 and 78 °C, as indicated also in specialty literature. ,− The glass transition temperature T g is due to the PET molecular movement and is determined from the second heating scan. Being a second order thermal transition, T g provides information regarding the softening of the amorphous portion of a polymer as the temperature is increased .…”

The Effect of Different Compatibilizers on the Properties of a Post-Industrial PC/PET Blend

“…The reactive extrusion experiments were implemented on a co-rotating twin-screw extruder (Collin ZK25, Maitenbeth, Germany), with L/D = 27, D = 25 mm (where L is the screw length and D is the screw diameter) and was operated under vacuum so that all of the resulting light components were forced out continuously. The temperature profile was set to 100–130–200–230–240 °C to avoid overheating and resin degradation [23], and the screw rotation rate was 100 rpm. The blends were cooled into a water bath and cut into pellets using a pelletizer.…”

Melt rheology and properties of compatibilized recycled poly(ethylene terephthalate)/(styrene‐ethylene‐ethylene‐propylene‐styrene) block copolymer blends

“…Melt blending has been thought to be a practical and economic approach to improve the properties of the notch-sensitive polymers [10][11][12]. Recently, several studies have been done to improve the toughness of R-PET by blending or compounding with different polymers, such as polycarbonate [13], acrylonitrile-butadiene-styrene [14,15], high-density polyethylene [16][17][18], linear low-density polyethylene [19,20], polypropylene [21,22], poly(ethyleneoctene) [23,24], styrene-ethylene-butadiene-styrene (SEBS) [25], and ethylene-glycidyl methacrylate copolymer [26]. Among them, elastomer modification is generally recognized to be a feasible choice to improve the toughness of R-PET based on the finer dispersion of small elastomer particles in the R-PET matrix.…”