Polycarbonate and Polyethylene terephthalate

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. 

The red allotropic form of phosphorus is relatively nontoxic and, unlike white phosphorus, is not spontaneously flammable. Red phosphorus is, however, easily ignited. It is a polymeric form of phosphorus, thermally stable up to ca. 450°C. In its finally divided form, it has proved to be a powerful flame-retardant additive.18 Elemental red phosphorus is a highly efficient flame retardant, especially for oxygen-containing polymers such as polycarbonates and polyethylene terephthalate). Red phosphorus is particularly useful in glass-filled polyamide 6,6, where high processing temperature (about 280°C) excludes the use of most phosphorus compounds.19 In addition, coated red phosphorus is used to flame retard nylon electrical parts, mainly in Europe and Asia.20... 

Among polyesters, polycarbonate and polyethylene terephthalate have been studied most extensively. 

Processing aides are available in many forms including low-viscosity liquid, powders, and pellets. They are used at a level of 0.1-2 percent by weight of the resin. Processing aids are often used with polyvinyl chloride, nylon, polycarbonate, and polyethylene terephthalate resins. 

Zhuang P, Kyu T, White JL (1988) Characteristics of hydroxybenzonic acid-ethylene terephthalate copolymers and their blends with polystyrene, polycarbonate, and polyethylene terephthalate. In SPE ANTEC tech, papers, vol 34, p 1237... 

The leading materials, in terms of market volume, are nylon, polycarbonate, polybutylene terephthalate, polyphenylene ether, poly-oxymethylene, and polyethylene terephthalate. 

A special case in terms of application of rotary kiln technology is the pyrolysis of mono fractions such as styrene, PMMA, polycarbonate, or polyethylene terephthalate. Polymethylmethacrylate is an example illustrate the advantages in using fluidized beds or rotary kilns. The feed material does not have a heteroatom problem and the pyrolysis product can easily be handled as a monomer source instead of feedstock. Therefore the... 

Rigid packages, such as bottles, boxes, trays, cups, vials, and various closures, are made from materials of sufficient strength and rigidity. Widely used polymers are high-density polyethylene, polypropylene, polybutene, poly(vinyl chloride), acrylic copolymers, polycarbonate, nylon, and polyethylene terephthalate (PET). Biodegradable PET is preferred due to environment concerns but it is expensive. The closure (or cap) of the container is typically made of polypropylene or... 

Polyphenylene ether (PPE) and polystyrene Partially incompatible polymer blends Polyethylene and polyisobutylene Polyethylene and polypropylene (5% PE in PP) Polycarbonate and polybutylene terephthalate... 

An important prerequisite for light-induced degradation is that the plastic absorb solar UVR or visible radiation as only the absorbed light can degrade the plastic. Polyolefins in theory do not have chromophores that can absorb light effectively, but trace impurities in the plastic and some of the additives in the material act as good chromophores. Plastics such as PS, polycarbonate (PC), and polyethylene terephthalate (PET), have aromatic functional groups that absorb UV radiation. 

The second most important class of commercial polycarbonate blends is derived by blending with commercial thermoplastic polyesters such as polybutylene tere-phthalate (PBT) and polyethylene terephthalate (PET). Both PBT and PET are crystallizable polymers and hence offer the expected chemical resistance advantages of the crystalline polymers in blends with polycarbonate. Among the thermoplastic polyester/polycarbonate blends, the PBT/PC blend has the major commercial volume, followed by the PET/PC blend. A copolymer of 1,4-cyclohexanedimethanol, ethylene glycol, and terephthalic acid (PCTG) forms a miscible blend with polycarbonate. PCTG/PC blend was earlier offered by Eastman (Ektar ) for specialty applications, but it is no longer commercial. 

At temperatures above the melting point, water reacts rapidly with certain polymers such as nylon, polycarbonate, polybutylene tereph-thalate (PBT), and polyethylene terephthalate (PET). This reaction results in a decrease in the molecular weight. At the same time, absorbed water can form steam that results in surface roughness, splay, and internal bubbles. The reaction between water and the molten polymer is accelerated by prolonged exposure to temperatures above the melting point. 

A new polymer modification process has been developed to reduce the cost of the engineering resin. The modification process is blended polymers. A blended polymer is a mixture of at least two polymers or a copolymer. There are three types of blended polymers miscible, immiscible, and compatible polymers. On occasion, blended polymers have properties that exceed those of either of the constituents. For instance, blends of polycarbonates (PC) resin and polyethylene terephthalate (PET) polyester were originally created to improve the chemical resistance of the PC. This is because PC actually had a fatigue resistance and low-temperature impact resistance that was superior to either of the individual polymers. 

Microcellular polymers are closed cell thermoplastics produced by gas nucleation. They have a high number of very small cells with a diameter of 10 pm, and bubble densities in excess of 100 million per cm. First produced in the early 1980s with the objective of reducing the amount of polymer used in mass produced items, these novel materials have the potential to revolutionise the way thermoplastic polymers are used today. PVC, PS, polycarbonate (PC), polyethylene terephthalate (PET) and not only these polymers can be applied for such kinds of products. As no harmful chemicals are used in the microcellular technology, it is likely that these new products will replace many types of foam now produced by processes that damage the environment [59]. 

To prepare membranes with artificial nanochannels, one can start with several polymer materials such as polyimide (PI), polycarbonate (PC), and polyethylene terephthalate (PET). A prerequisite to apply these kinds of polymers for nanochannel fabrication is that they are easy to process and susceptible to different etching techniques to produce nano-sized channels of different morphologies. Current methods for this purpose include ion-track-etching, electrochemical etching, and laser techniques. Once the nanochannels have been produced, one needs to functionalize the channel inner wall to obtain different functions. Following are some examples of polymer decorated nanochannels. 

A polymer is a material composed of large macromolecules. These macromolecules are formed by chains of hundreds or thousands of connected (polymerized) monomer molecules. The three main classes of polymers are thermoplastics, elastomers and thermosets. They differ in the degree of cross-linking of their macromolecules -from no cross-linking (thermoplastics) to moderate cross-linking (elastomers, rubbers) to high cross-linking (thermosets). Thermoplastics commonly used in microfluidics include materials like polymethylmethacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET) or cyclic olefin copolymers (COC). Silicones (like poly-dimethylsiloxane, PDMS) are a typical class of elastomers. Thermosets include photoresist materials like SU-8 and others. 

About a half centuiy has passed since synthetic leather, a composite material completely different from conventional ones, came to the market. Synthetic leather was originally developed for end uses such as the upper of shoes. Gradually other uses like clothing steadily increased the production of synthetic leather and suede. Synthetic leathers and suede have a continuous ultrafine porous structure eomprising a three-dimensional entangled nonwo-ven fabric and an elastic material principally made of polymethane. Polymeric materials consisting of the synthetic leathers are polyamide and polyethylene terephthalate for the fiber and polyurethanes with various soft segments, such as aliphatic polyesters, polyethers and polycarbonates, for the matrix. 

Perfluoroethylenes have been characterized by desorption chemical ionization and tandem mass spectrometry Fourier transform ion cyclotron resonance mass spectroscopy has also been applied to the identification of polymers, eg. polyethylene glycols. Comparative complimentary plasma desorption mass spectrometry/secondary ion mass spectrometry has been applied to the identification of oligomers of various polymers including polyethylene glycol, polytetrafluoroethylene, polycarbonate, polyacrylates, polyethylene terephthalate and siloxanes. ... 

In this way an accurate ranking of relative stability of different polymers can be obtained. For example, the polymers polyetherimide (PEI), polycarbonate (PC), polyethylene terephthalate (PET) and polyvinyl chloride (PVC) differ in their thermal stabilities due to the chemical make-up of their backbones (in the order PEI > PC > PET > PVC) and the... 

Several examples have been presented, for example, the thermo-oxidative degradation of PEGs, PAs, polycarbonates (PCs), polyetherimides (PEIs), and polyethylene terephthalates (PBTs) monitored by MALDI-TOF MS. Valirable stmctural information on the photo-oxidized PEIs (ULTEM) species can be extracted from the MALDI spectra. Hie data revealed that this particular way of degradation involves several simultaneous reactions. The ultrasonic degradation of PMMA and PEG was shown to be useful for the MALDI-TOF MS... 

In 1954 the surface fluorination of polyethylene sheets by using a soHd CO2 cooled heat sink was patented (44). Later patents covered the fluorination of PVC (45) and polyethylene bottles (46). Studies of surface fluorination of polymer films have been reported (47). The fluorination of polyethylene powder was described (48) as a fiery intense reaction, which was finally controlled by dilution with an inert gas at reduced pressures. Direct fluorination of polymers was achieved in 1970 (8,49). More recently, surface fluorinations of poly(vinyl fluoride), polycarbonates, polystyrene, and poly(methyl methacrylate), and the surface fluorination of containers have been described (50,51). Partially fluorinated poly(ethylene terephthalate) and polyamides such as nylon have excellent soil release properties as well as high wettabiUty (52,53). The most advanced direct fluorination technology in the area of single-compound synthesis and synthesis of high performance fluids is currently practiced by 3M Co. of St. Paul, Minnesota, and by Exfluor Research Corp. of Austin, Texas. 

Engineering resins can be combined with either other engineering resins or commodity resins. Some commercially successhil blends of engineering resins with other engineering resins include poly(butylene terephthalate)—poly(ethylene terephthalate), polycarbonate—poly(butylene terephthalate), polycarbonate—poly(ethylene terephthalate), polysulfone—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 oxide)—polystyrene, and nylon—polyethylene. 

Friedrich et al. also used XPS to investigate the mechanisms responsible for adhesion between evaporated metal films and polymer substrates [28]. They suggested that the products formed at the metal/polymer interface were determined by redox reactions occurring between the metal and polymer. In particular, it was shown that carbonyl groups in polymers could react with chromium. Thus, a layer of chromium that was 0.4 nm in thickness decreased the carbonyl content on the surface of polyethylene terephthalate (PET) or polymethylmethacrylate (PMMA) by about 8% but decreased the carbonyl content on the surface of polycarbonate (PC) by 77%. The C(ls) and 0(ls) spectra of PC before and after evaporation of chromium onto the surface are shown in Fig. 22. Before evaporation of chromium, the C(ls) spectra consisted of two components near 284.6 eV that were assigned to carbon atoms in the benzene rings and in the methyl groups. Two additional... 

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. 

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