Polycarbonates containing

Valkirs et al. [105] have conducted an interlaboratory comparison or determinations of di- and tributyltin species in marine and estuarine waters using two methods, namely hydride generation with atomic absorption detection and gas chromatography with flame photometric detection. Good agreement was obtained between the results of the two methods. Studies on the effect of storing frozen samples prior to analysis showed that samples could be stored in polycarbonate containers at - 20 °C for 2 - 3 months without significant loss of tributyltin. 

It has been determined from X-ray diffraction measurements that polycarbonate containing Bisphenol AF moiety are all amorphous.6 The (Tg) of poly(carbonate)s increases with an increase in hexafluoroisopropylidene unit from 149°C for Bisphenol A poly(carbonate) (3) to 169°C for Bisphenol AF poly(carbonate) (2) (Table 9.3).6 Thermooxidative stability is also improved by the introduction of fluorine atoms into the isopropylidene units. The 10% weight-loss temperature (DT10) increases from 429 to 460°C and the residual weight (RW) at 500°C goes from 37 to 57% by perfluorination of the isopropylidene units. 

Gao LJ, Du FG, Xiao M, Wang SJ, Meng YZ (2008) Thermally stable aliphatic polycarbonate containing bulky carbazole pendants. J Appl Polym Sci 108 3626-3631... 

Synthesis of high Tg co-polycarbonates containing 3,3-bis(4-hydroxyphenyl)-l-phenyl-lH- indol-2-one and bisphenol A biphenols, which adhere to aluminum. 

Figure 1. X-ray photograms of polycarbonate containing 28.6% of tricresyl phosphate Glass Transition Temperatures (T0)...

FIGURE 8.1 HRR for polycarbonate and polycarbonate-containing silicone (two repeated tests for each sample). (From Kashiwagi, T. et al., A nonhalogenated, flame retarded polycarbonate, in Conference of Advanced Fire Resistant Aircraft Interior Materials, Atlantic City, NJ, February 9-11, 1993, 175.)... 

Chung JYJ, Mason JP (1996) Toughened aromatic polycarbonate containing silicone rubber powder as molding composition. US Patent 5556908... 

Tsutsumi et al. (1986, 1988) reported photogeneration efficiencies of N-phenylcarbazole (NPCZ) doped polycarbonate containing small concentrations of an electron acceptor 2.6-dimethyl-p-benzoquinone. The thermali-... 

Results for a 20 pm thick sample of polycarbonate containing 50 mass% TPD for a field of 1.5 x 107Vm-1 at 296 K with charges injected from an indium tin oxide (ITO) electrode coated with a 0.1 pm thick layer of PPV are shown in Fig. 8.30(b). The limiting current is close to the trap-free SCLC, indicating that the PPV-coated ITO acts as an efficient hole-injecting electrode. The lower curve is the TOF transient recorded under identical conditions. The arrow on the lower curve indicates the transit time and that on the upper curve is 0.8 of this value. The step-voltage response is therefore close to the theoretical prediction. 

The reactions were carried out in borosilicate glass, quartz, and polycarbonate containers. There was very little attack upon the glass by fluoride ion. NaF was found as an impurity in only one or two preparations, and this probably was caused by a high hydrogen ion concentration. 

Figure 46. Photocurrent transients for hole transport in TTA (40 wt.%)-doped polycarbonate containing as an added impurity l,l-bis(p-diethylaminophenyl)-4,4-diphenyl-l,3-butadiene (BD) at various concentrations. The current (vertical) scale is arbitrary. The samples were 16 pm thick, the temperature 298 K, and the field strength 3.75 x 10 V cm . (Reprinted with permission from Ref [74j].)...

Polycarbonates and polyanhydrides are grouped together, although polycarbonates contain the functionality -0-C(0)-0- in their backbone, and polyanhydrides contain the functionality -C(0)-O- (O)-. Both types of polymers are common in practice. 

NEC has a target to phase out the use of all halogenated flame retardants by 2011. In 1999 the company launched a polycarbonate containing a silicone flame retardant that it claims to be far superior to conventional flame retardants and is neither phosphorus nor halogen based and can be recycled up to five times for the same purpose. 

The samples are placed, usually immediately after being collected, in different types of containers made of plastic, aluminium or other metals, glass, etc., depending on their future use and the storage temperatures. In this preliminary phase the BCAA decided to use polycarbonate containers for soils, sediments, moss and algae polystyrene containers for filters collecting marine suspended particulate matter polystyrene Petri capsule for filters with atmospheric particulate matter low-density polyethylene (LDPE) containers for snows and polyethylene bags for pack-ice core. 

Sakashita, T. Shimoda, T. Polycarbonate Containing Terminal Hydroxyl Groups, Low Sodium and Chlorine Content US Patent 5,276,129, January 4, 1994. 

A series of copolymers containing both imide and carbonate units have been reported by Sato et al. [84,85]. The structures are depicted in Table 26. Two copolymers have been synthesised and coreacted together in differing ratios above a 1 1 ratio thermotropic behaviour was observed. The first copolymer was constructed from pyromellitic dianhydride separated from carbonate groups by aliphatic spacers. This polymer was isotropic on its own. The second polymer was a thermotropic polycarbonate containing a biphenyl unit and spacers. The MI score=9.1 at the onset of mesogenic properties. This value is surprisingly low and is about half a unit lower than observed with PEIs. 

Table I. Oxygen Permeabilities of Polycarbonates Containing Bisphenols Substituted at...

Table III. Oxygen Permeabilities of Polycarbonates Containing Bisphenols With and Without Methyl Groups at the 3,3 -Positions of the Aromatic Rings...

A similiar comparison can be made between permeability data of polyesters and polycarbonates containing "polyester-like" monomers. For example, polycarbonates 26 and 27, which contain predominantly bisphenols which are structurally similiar to the repeat unit (circled) of an alkyl terephthalate polymer (PBT), possess essentially the same low permeability as that polyester (Table V). Furthermore, there has been a recent announcement (3 ) that aliphatic polycarbonates, such as polypropylene and polyethylenecarbonate, are being developed as potential gas barrier materials. In summary these results suggest that the relative low permeabilities of commercial polyesters and high permeabilities of commerical polycarbonates are not a direct consequence of the ester or carbonate links, but are due instead to the structure of the monomers they are prepared from, i.e., the aliphatic diol and aromatic bisphenol, respectively. 

Use presoaked polycarbonate containers rather than glass or plastic when doing trace analysis of cations. 

Anand, V.D. and Ducharme, D.M. (1976). Stability of chromium ions at low concentrations in aqueous and biological matrices stored in glass, polyethylene, and polycarbonate containers. Natl. Bur. Standards Spec. Publ. 422. Accuracy in trace analysis Sampling, sample handling and analysis, pp. 611-619. 

We have entered into a culture of zero risk. Om role of industry is to integrate and even anticipate this evolution and its impact on the composition of our products. And the media s role is to alert us. Provided, however, that this does not become overblown. However, in the case of bisphenol A, from dramatization to dramatization, the media have come to say that the mere touch of a drink, food or our skin with a polycarbonate containing bisphenol A poisoned our blood - and no matter that it enables the manufacture of a very transparent plastic, a quality particularly necessary in incubators for premature babies, for example. 

MALDI-TOF spectra of commercial polycarbonates display peaks due to open-chain macromolecules along with peaks due to cyclics. Polycarbonates containing porphyrin or fullerene units in the main chain fullerene are easily analyzed by MALDI-TOF. ... 

Dow Coming Toray Silicone in Japan has proposed the use of a silicone-based FR for polycarbonate compounds. A heat treatment at 380 °C for polycarbonate containing the silicone material has been shown to generate a phenyl silyl ether linkage that appears to lead to flame retardancy for the formulation. 

Electronics giant NEC of Japan has entered the fray with a polycarbonate containing a silicone FR. The company has licensed Sumitomo Dow to be the manufacturers of this special polycarbonate. Sold as NuCycle, the new material is used to make NEC s liquid crystal display monitors and battery packs for portable computers. It is also applied for other polycarbonate applications, covering projectors and plasma flat screens. 

---