Polyethylene terephthalate blends

Convincing evidence for phosphorus/bromine synergy has now been found in a 2/1 polycarbonate/polyethylene terephthalate blend. Phosphorus and bromine blends were studied as well as compounds which have both elements in the same compound. The relative flame retardant efficiencies of phosphorus and bromine are also reported. 

Bromine/phosphorus synergy was investigated in a 2/1 polycarbonate/ polyethylene terephthalate blend. Synergy was demonstrated when blends of brominated and phosphorus compounds were used. The synergy is even more pronounced with a compound containing both elements in the same compound. This was dependant on the bromine/phosphorus ratio in the compound. Phosphorus was shown to be 9 to 10 times more effective than bromine in this resin blend. 

Suloff, E. C. (2001). Modeling the adsorption of aldehydes and ketones to novel polyethylene terephthalate) blends by inverse gas chromatography to develop an improved polymer for food packaging. Ph.D. Dissertation, Virginia Tech, Blacksburg. 

Polyethylene Terephthalate Blends Wilfong et al. [1986] reported on the effects of blending low concentrations (1 to 10 wt%) polyolefin with PET on the crystallization and toughening behavior of the latter. The authors... 

Polyethylene Terephthalate Blends Only few papers related to the crystallization of a PET matrix in immiscible crystalline/crystalline blends have been published. 

Fire retardants used in polystyrene (PS) include montmorillonite clay, polytetrafluoro-ethylene (PTFE) [8], bromine-based flame retardants such as brominated bisphenol A [9], brominated phenyl oxide or tetrabromophthalic anhydride, or magnesium hydroxide [10,11]. Sanchez-Olivares and co-workers [12], in their study of the effect of montmorillonite clay on the burning rate of PS and PS-polyethylene terephthalate blends, showed that increased combustion rate accompanied the incorporation of montmorillonite particles in high-impact polystyrene (FlIPS) formulations. 

Fig. 7.38 Concentration dependence of zero shear viscosity at 260, 280, and 300 °C of polyethylene terephthalate blended with polyamide-6,6. Points are experimental with the error bars indicating the error of measurements 2 % (Utracki et al. 1982)...

Selar PT Polyethylene terephthalate blend, PET, (blend) E. I. du Pont de Nemours... 

LicciardeUo, A., Auditore, A., Samperi, E, PugUsi, C. (2003) Surface evolution of polycarbonate/polyethylene terephthalate blends induced by thermal treatments. Appl. Surf. Set,203-204,556-560. 

M. Yazdani-Pedram, H. Vega, J. Retuert, and R. Quijada, Compatibiliz-ers based on polypropylene grafted with itaconic acid derivatives, effect on polypropylene/polyethylene terephthalate blends, Polym. Eng. Sci, 43(4) 960-964, April 2003. 

Lorenc-Grabowska E, Gryglewicz G, Machnikowski J, Diez MA, Barriocanal C (2009) Activated carbons from coal iitch and polyethylene terephthalate blends for the removal of phenols from aqueous solutions. Energy Fuels 23(5) 2675-2683... 

No.l2, 1997,p.3035-43 CHARACTERIZATION OF POLYETHYLENE TEREPHTHALATE AND POLYETHYLENE TEREPHTHALATE BLENDS... 

CHARACTERIZATION OF POLYCARBONATE/POLYETHYLENE TEREPHTHALATE BLENDS UNDERGOING TRANSESTERIFICATION... 

A 2/1 blend of polycarbonate and polyethylene terephthalate (PC/PET) was flame retarded with bromine, phosphorus, a blend of bromine and phosphorus, and compounds containing both phosphorus and bromine in the same molecule. All compositions contained 0.5 % Teflon 6C as a drip inhibitor and where specified 5 % of an impact modifier. 

We previously reported that brominated aromatic phosphate esters are highly effective flame retardants for polymers containing oxygen such as polycarbonates and polyesters (9). Data were reported for use of this phosphate ester in polycarbonates, polyesters and blends. In some polymer systems, antimony oxide or sodium antimonate could be deleted. This paper is a continuation of that work and expands into polycarbonate alloys with polybutylene terephthalate (PBT), polyethylene terephthalate (PET) and acrylonitrile-butadiene-styrene (ABS). 

Haralabakopoulos, A. A., Tsiourvas, D. and Paleos C. M., Chain extension of polyethylene terephthalate) by reactive blending using diepoxides, J. Appl. Polym. Sci., 71, 2121 (1999). 

Similar results are also obtained from the CNT-filled polymer blends such as CNT-filled polyethylene terephthalate (PET)/polyvinylidene fluoride, PET/nylon 6,6, PET/polypropylene, and PET/high-density polyethylene blends. 

Most of the polymer s characteristics stem from its molecular structure, which like POE, promotes solubility in a variety of solvents in addition to water. It exhibits Newtonian rheology and is mechanically stable relative to other thermoplastics. It also forms miscible blends with a variety of other polymers. The water solubility and hot meltable characteristics promote adhesion in a number of applications. PEOX has been observed to promote adhesion comparable with PVP and PVA on aluminum foil, cellophane, nylon, poly(methyl methacrylate), and polyethylene terephthalate), and in composite systems improved tensile strength and Izod impact properties have been noted. 

Engineering resins can be combined with either other engineering resins or commodity resins. Some commercially successful blends of engineering resins with other engineering resins include poly (butylene terephthalate)—poly(ethylene terephthalate), polycarbonate—poly(butylene terephthalate), polycarbonate—polyethylene terephthalate), p olysulfone—poly (ethylene terephthalate), and poly(phenylene oxide)—nylon. Commercial blends of engineering resins with other resins include modified poly(butylene terephthalate), polycarbonate—ABS, polycarbonate—styrene maleic anhydride, poly(phenylene... 

Copolymers of polyethylene terephthalate (PET) with nonaromatic acids, poly(ethylene ethers) or hydroxy acids have been blended with starch to produce compostable products such as fibers and films.60 Starch contents up to 80% by weight are claimed. 

Crystallization Studies of Blends of Polyethylene Terephthalate and Poly butylene Terephthalate... 

Blends of polybutylene terephthalate and polyethylene terephthalate are believed to be compatible in the amorphous phase as judged from (a) the existence of a single glass-transition temperature intermediate between those of the pure components and (b) the observation that the crystallization kinetics of the blend may be understood on the basis of this intermediate Tg. While trans esterification occurs in the melt, it is possible to make Tg and crystallization kinetics measurements under conditions where it is not significant. When the melted blend crystallizes, crystals of each of the components form, as judged from x-ray diffraction, IR absorption, and DSC. There is no evidence for cocrystallization. There is a slight mutual melting point depression. 

Whereas atactic PS is an amorphous polymer with a Tg of 100 CC, syndio-tactic PS is semicrystalline with a Tg similar to aPS and a Tm in the range 255-275 °C. The crystallization rate of sPS is comparable to that of polyethylene terephthalate). sPS exhibits a polymorphic crystalline behavior which is relevant for blend properties. In fact, it can crystallize in four main forms, a, (3, -y and 8. Several studies [8] based on FTIR, Raman and solid-state NMR spectroscopy and WAXD, led the a and (3 forms to be assigned to a trans-planar zig-zag molecular chain having a (TTTT) conformation, whereas the y and 8 forms contain a helical chain with (TTG G )2 or (G+G+TT)2 conformations. In turn, on the basis of WAXD results, the a form is said to comply with a unitary hexagonal cell [9] or with a rhombohedral cell [10]. Furthermore, two distinct modifications called a and a" were devised, and assigned to two limiting disordered and ordered forms, respectively [10]. 

A limited number of patents concern sPS blend which are not compatible. In these cases the properties that are described are functional ones and not related to the poor toughness of sPS. For instance, blends of sPS and partially saponified ethylene-vinyl acetate copolymers exhibit improved gas barrier properties (entry 11) small amounts of sPS added to polyethylene terephthalate) (although the patent actually claims a wide range of compositions) are useful to increase the polyester crystallization rate (entry 5). 

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