PC/PMMA

Table 9 compares the most important properties of substrate materials based on BPA-PC, PMMA, and CPO (three different products) (216,217). The future will prove if the current disadvantages of CPO against BPA-PC regarding warp, processibiUty (melt viscosity), and especially cost can be alleviated. CycHc polyolefins (CPO) and, especially cycloolefin copolymers (COC) (218) and blends of cycloolefin copolymers with suitable engineering plastics have the potential to be interesting materials for substrate disks for optical data storage. 

Of the various plastics available, such TPs as nylon, PC, PMMA, PUR, PET, and ABS are among those categorized as hygroscopic. 

More than 200 users annually consume over US 55 million of light stabilisers. IR absorbers (e.g. amine, antimony salt mixture) protect against IR radiation applicable in PC, PMMA, PVC, etc. 

Figure 5.73 Toughness, elongation at break, Et, yield strength, ay, and tensile strength cr, as a function of composition for a PC/PMMA blend. Reprinted, by permission, from T. Kyu, J. M. Saldanha, and M. J. Kiesel, in Two-Phase Polymer Systems, L. A. Utracki, ed., p. 271. Copyright 1991 by Carl Hanser Verlag.

The density and n value of a polymer crystal are greater than those of an amorphous polymer. Many polymers are opaque because of the presence of ordered clusters of crystals called spherulites which have different n values. ptfe, which is highly crystalline, is opaque but amorphous polycarbonate (PC), PMMA, and PS are noncrystalline and clear. 

FIGURE 2.27 UV transmittance spectra of PC, PMMA, glass, and PDMS substrates [224]. Reprinted with permission from the American Chemical Society. 

Side vents are often used with polymers for optical applications (PC, PMMA, PET), direct extrusion of high quality films (PET), or for fiber spinning (PA) they ensure that condensate or degraded polymer cannot re-enter the product flow of the ZSK (see Fig. 10.12). 

Blends of ASA with many of the common thermoplastic materials are state of the art. The properties of the finished products depend to a large extent on the polymer compatibility often induced by the use of reactive polymers. Only a few of these blends have reached a significant commercial status. The largest blend products in this area are ASA-PC blends followed by ASA-PBT and ASA-PC-PMMA blends. Combinations of ASA with high-Tg matrix polymers are also frequently found in commercial products. 

Measurements were conducted on commercially available samples of PC, PMMA and PS. The trade names, the weight average molecular weights and the glass transition temperatures, as measured by DSC, are listed in Table I. 

Fig. 22 MDSC scans of the (a) first, and (b) second heating runs recorded for the 1 1 1 molar PC/PMMA/PVAc coalesced blend. The sample was held for 3 min at 170°C after the first heating [35]...

Fig. 23 DSC thermogram of the coprecipitated PC/PMMA/PVAc blend, first heating scan...

DSC scans recorded for PC/PMMA/PVAc blends obtained by solvent-casting and coprecipitation evidenced four distinct glass-transitions, one for each component polymer and one indicating that some of the PMMA and PVAc chains were mixing (see Fig. 23). 

We also observed that the PC chains possess a preferred ability to form inclusion compounds with y-CD in solution, when competing with PMMA and PVAc. From the XH NMR spectrum of the coalesced 1 1 1 PC/PMMA/PVAc blend (not shown), the molar ratio of PC PMMA PVAc was determined to actually be 1.6 1 1.4 compared to the initial molar ratio of 1 24 24, respectively, used in solution to form their common y-CD-IC. Despite the initial 1 24 24 PC PMMA PVAc molar ratio in solution, the PC component in the coalesced PC/PMMA/PVAc blend is still prevalent over the PMMA and PVAc components, which indicates that there may be additional factors that govern the inclusion process from a multiguest system. We believe that this very strong preference of the host y-CD molecules for PC chains, rather than the other two possible guests, is due to their different hydrophobicities. Although the final molar ratio of the coalesced ternary blend can be somewhat controlled by modifying the initial molar ratio of polymers in their common solution, our eventual aim is to be able to adjust, as desired, the constituent polymer ratios in coalesced ternary blends. 

Incoshield - concentrates of nickel-coated carbon fiber in PPS, PC, PMMA, PEI, PA-6, PA-12. Concentrates are used for production of conductive polymers IB Company, Franklin, NJ, USA... 

These solvent-free, so-called PI, adhesives are used to join PC, PMMA, PET, PS, PVC, and glass, whereby at least one component must be transparent, so that the composites usually comprise plastic-plastic, glass-plastic and plastic-metal combinations (optics industry, microelectronics). In exceptional cases (fixation of structural components on nontransparent carriers), it is also possible to cure a surrounding strip of adhesive directly. 

Landry and Henrichs [63] applied dynamic mechanical spectroscopy and H NMR to investigate sub-T motion in polycarbonate(PC)/PMMA and PC/poly(cyclohexylene dimethylene terephthalate)(PCHDMT). Examination of H NMR spectra and relaxation times led them to conclude that local... 

Table 10.1. Observed and calculated values of H T, (lefthand) and Tjp (righthand) for PC/PMMA = 3/7, 5/5 and 7/3. The calculated (averaged) values are obtained by the assumption that T or Tip values of PC and PMMA in the blend are equal to those of PC and PMMA homopolymers (Equation (10.5)).

Chu et al. [96] heated PS/PVME above 139°C for 30 min and quenched it at 0°C. Tip relaxation values of component polymers were observed through well-resolved peaks. By comparing these values to Tip of non-heated blends at various composition determined experimentally, they estimated the coexistent compositions at various heat-treatment temperatures and a LCST phase diagram was obtained. Asano et al. analyzed relaxation curves of PC/PMMA [92] and PS/PVME [52] by using Equation (10.9). 

Ti values of PC and PMMA in PC/PMMA = 50/50 agree well to show its miscibility on a scale of —20 nm. They observed relaxation curves after heat treatment for 30 min at various temperatures. When heated above 150°C, the relaxation curve becomes nonsingle exponential, and they attributed this temperature of 150°C to the phase-separation temperature of PC/PMMA = 50/50. The relaxation curves were fitted to Equation (10.9) to deduce the coexistent compositions at various temperatures to give a LCST phase diagram. They further studied kinetics of phase separation, which will be discussed in the following. 

PC PMMA immiscible steady state shear Kasajima et al., 1981... 

Co-continuous morpholoey A different type of morphological structure, cocontinuity of the phases, can prove beneficial by drawing on properties of both constituents stiffness from a rigid polymer and high strain at break from a ductile one. This is illustrated by Kyu et al. (1991) who studied the toughness enhancement of PC/PMMA blends. The blends were prepared using three different procedures ... 

PC/PMMA Solvent casting in THF, Phase separation, solvent induced Saldanha and Kyu, 1987... 

Mixtures of polar polymers, such as PVC, PC, PMMA, TPU, PA, PEST, PGI, SAN, or ABS could be compatibilized by incorporation of two copolymers, the first containing vinyl alcohol, the second an anhydride. For example, blends of TPU with Phenoxy, EVAl, COPO, modified cellulose, and/or polyalkylene oxide, had attractive physical, optical and barrier properties, and were melt-processable without degradation. They could be transformed into films, sheets, or bottles with good barrier properties. Blends containing PA were used for films, tubes, toys, gears, bearings, shafts, curtain sliders, door rollers, etc. The blends with elastomers were reported suitable for improved wiper blades [La Fleur et al., 1994]. 

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