Polycarbonate film

Fig. 4. Diagram of the two-step process to manufacture nucleation track membranes, (a) Polycarbonate film is exposed to charged particles in a nuclear reactor, (b) Tracks left by particles are preferentially etched into uniform cylindrical pores (8).

Tests were conducted using an approximately 30-cm-diameter, 80-/rm-thick polycarbonate film with brass backing plate. A 50-mm-diameter spherical discharge electrode was used to initiate discharge of the charged film... 

FIQURE 2-6.2.3. Transition from brush discharge to PBD on 80-/.m polycarbonate film. 

In the photographic field polycarbonates now complete with ABS for projector housings, whilst in cameras polycarbonates are now used in the shutter assembly, film drive, flash-cube sockets and lens holders. One popular low-cost camera recently introduced into the UK market had at least eight parts moulded from polycarbonate. Polycarbonate film is also used for photographic purposes, e.g. for quality colour fine engravings. 

Wang K., Li Y.S., Silver doping of polycarbonate films for surface-enhanced Raman scattering, Vibrational Spectrosc. 1997 14 183-188. 

Figure 6 Emission spectra of polycarbonate film (excitation at 310 nm) after photolysis for 0, 15, 30, and 60 min. (Adapted from Ref. 233.)...

Polycarbonate films with a typical thickness of 10-15 qm containing 2 wt% of molecularly dispersed BET-TIE are cast following the modified reticulate doping technique (MRDT) (Laukhina et al, 1995) as illustrated in Eig. 3.21. Then the surfaces of the samples are treated with the vapour of a Br2/CH2Cl2 solution. 

Laukhina EE, Merzhanov VA, Pesotskii SI, Khomenko AG, Yagubskii EB, Ulanski J, Kryszewski M, Jeszka JK (1995) Superconductivity in reticulate doped polycarbonate films, containing (BEDT-TTE)2l3. Synth Met 70 797-800... 

Similar approach has also been taken by Ferain and Legras [133,137,138] and De Pra et al. [139] to produce nanostructured materials based on the template of the membrane with etched pores. Polycarbonate film was also of use as the base membrane of the template, and micro- and nanopores were formed by precise control of the etching procedure. Their most resent report showed the successful formation of ultrasmall pores and electrodeposited materials of which sizes were as much as 20 nm [139]. Another attractive point of these studies is the deposited materials in the etched pores. Electrochemical polymerization of conjugated polymer materials was demonstrated in these studies, and the nanowires based on polypyrrole or polyaniline were formed with a fairly cylindrical shape reflecting the side wall structure of the etched pores. Figure 10 indicates the shape of the polypyrrole microwires with their dimension changes by the limitation of the thickness of the template. 

Fig. 50. Dependence of the thermaliz-ation distance r and initial quantum yield d>0 for polycarbonate film on tri-phenylamine concentration [287]...

Fig. 51. Spectral dependence of the photogeneration efficiency for polycarbonate film with concentration of isopropylcarbonate 40% [289], Electric field strength in Vcm- 7 - 5 x 104 2 - 103 3 - 1.5 x 103...

The effective carrier mobilities and their dependence on concentration for benztriazole derivatives embedded in polycarbonate were explained by the percolative aspects in photoconductivity [296]. The observed field dependence of the mobility for polycarbonate films doped with diethynylaminobenzaldehy-de-diphenyl hydrazone cannot be accounted for by any known hopping model [297]. The influence of the nature of the polymer matrix on photogeneration and transport properties of the molecule doped polymers was investigated in some papers [57, 58, 298, 299],... 

The Onsager theory of geminate recombination was qualitatively consistent for aryl-substituted thiapyrylium salt and dialkylamino-substituted triphenyl-methane dispersed in polycarbonate film [301]. The quantum yield of Hie photogeneration was equal to 0.5 at the electric field strength of 106 V cm-1, mobility of I0 12m2 V-1 s-1. Hole and electron conductivity was established. In a triphenylamine-lexan system doped with a boron diketone acceptor, the... 

Fig. 54. Spectrum of the photoinjection efficiency from selenium layer into polycarbonate film with 35% content of triphenylamine [308]...

For many years, it has been known that a small quantity of plasticizer acts as an anti plasticizer for polyvinyl chloride (PVC). During a recent search for effective plasticizers for polycarbonate, W. J. Jackson and J. R. Caldwell found several groups of compounds which acted as antiplasticizers. They increased the tensile modulus and strength and reduced the elongation of polycarbonate films. In contrast to plasticizers, these antiplasticizers affected glass transition temperature quite differently. Their mechanism is explained by the fact that they either increase crystallinity or reduce the mobility of the polymer chain through the bulkiness of their molecules. 

From a practical point of view the purpose of this study was to increase the crystallizability of the polycarbonate by incorporating in it well-defined amounts of plasticizer. With this modification, crystalline polycarbonate films could be made with a higher modulus of elasticity, and these would extend the usefulness of the polymers as photographic film bases. When this study was completed an article was published by Sears and Darby (16), who made an extensive study of the plasticization of polycarbonate using 50 plasticizers of widely differing types. The crystallization tendency in the presence of plasticizers was recognized by these authors as a problem and was circumvented by quench cooling. 

The mechanical properties and the tensile heat distortion temperatures (softening temperatures) of cast and pressed polycarbonate films containing differing amounts of plasticizer have been measured (Table III and IV). 

Tabla III. Mechanical and Thermal Properties of Cast Plasticized Polycarbonate Films... 

Why is it that the maximum modulus of elasticity of crystalline film samples of polycarbonate, even when oriented, does not increase considerably over that of amorphous samples Van Kerpel (19) examined the x-ray diffraction pattern of a crystallized polycarbonate sample held under tension and showed that the crystal lattice of the polycarbonate elongates quite easily in the direction of stretch. He found that the lattice distance (d 2.670 A.) increases to d 2.691 A. and d — 2.714 A. when the polycarbonate film is elongated by 5 and 10%, respectively. 

Incorporating small amounts of plasticizer during the manufacture of solvent-cast polycarbonate films results in films with a higher modulus of elasticity, a higher stiffness, and higher heat distortion temperatures than films cast from unplasticized polymer. 

The polycarbonate films containing the additives were completely transparent, and x-ray diffractometric curves gave no indication of crystallinity. Films with a thickness of about 2 mils could be tightly creased without cracking, but 3- to 4-mil films often cracked under these conditions. Film properties of the polymers from bisphenols I and II and from bisphenol A are listed in Tables I to III, respectively. Some conventional plasticizers also are listed at the bottoms of the tables to show their effect on the film properties. 

It is surprising that the tensile moduli of the polycarbonate films were increased so much by the antiplasticizers, and it is even more surprising that antiplasticizer concentrations of 30% (and even 40% in two cases) could be tolerated before the... 

Oxidative Stability of Carboxylated Polyesters. The polyesters which were extended with dianhydrides are those in Table I which were soluble in the lacquer solvents. Of these, theoretical considerations indicate that T50I(NPG) should be the most oxidatively and thermally stable because it is the only one with a completely aromatic acid component (terephthalic and isophthalic), and the glycol component has the stable neopentyl structure. When K-l polycarbonate films containing 5% of this polyester extended with PMDA were heated in a forced-air oven at 200°C, the film life (time to brittleness when creased) was not lowered appreciably (compared with a control containing no carboxylated polyester). The incorporation of 5% of the similar carboxylated T50H(NPG)... 

Figure 3. Time lag for diffusion of CO at 35 °C in a U.9 mil thick polycarbonate film conditioned by prior exposure to C02 The data are from Ref. 15. Calculated time lags based on the matrix model (solid line) and the dual-mode model (broken line) use parameters determined from fitting the sorption and permeation data.

End-fed sheeting die. Design a 1000 mm wide end-fed sheeting die with a 1 mm die land gap for a polycarbonate film. For the solution of the problem assume a manifold diameter of 15 mm and the longest portion of the length should be 50 mm. Using the above information we can write,... 

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