Poly 2,2 -p-

Other Polymers. Besides polycarbonates, poly(methyl methacrylate)s, cycfic polyolefins, and uv-curable cross-linked polymers, a host of other polymers have been examined for their suitabiUty as substrate materials for optical data storage, preferably compact disks, in the last years. These polymers have not gained commercial importance polystyrene (PS), poly(vinyl chloride) (PVC), cellulose acetobutyrate (CAB), bis(diallylpolycarbonate) (BDPC), poly(ethylene terephthalate) (PET), styrene—acrylonitrile copolymers (SAN), poly(vinyl acetate) (PVAC), and for substrates with high resistance to heat softening, polysulfones (PSU) and polyimides (PI). 

Property Polystyrene (PS) Poly(styrene-i) (j-acrjio-nitrile ) (SAN) Glass-fil led PS High impact PS HIPS Acrylonitrile— butadiene—styrene terpolymer (ABS) Type 1 Type 2 Standard ABS Super ABS... 

Fig. 10. X-ray reflectivity curves of polystyrene (PS)/poly-p-bromostyrene (PBrS) on a glass substrate before (solid line) and after annealing for 13 h at 130 °C (dashed tine) [191]. The width of the interface changes from 1.3 nm to 2.0 nm due to interfacial mixing of components. The X-ray wavelength is 0.154 nm and films have a thickness of 37.8 nm (PS) and 45.0 nm (PBrS), respectively...

Table 1. Common materials used in quenched-fluorescence oxygen sensing (Ru(dpp)3(C104)2 tris(diphenylphenantroline) ruthenium(II) perchlorate PtOEPK platinum(II)-octaethyl-porphine-ketone PtPFPP platinum(II)-tetrakis(pentafluorophenyl)porphine PS.poly(styrene), PSu poly(sulfone) PSB poly(styrene-butadiene) block co-polymer PVC polyvinylchloride) APET amorphous poly(ethyleneterephthalate) PE poly(ethylene).

In 1968, a French Patent issued to the Sumitomo Chemical Company disclosed the polymerization of several vinyl monomers in C02 [84], The United States version of this patent was issued in 1970, when Fukui and coworkers demonstrated the precipitation polymerization of several hydrocarbon monomers in liquid and supercritical C02 [85], As examples of this methodology, they demonstrated the preparation of the homopolymers PVC, PS, poly(acrylonitrile) (PAN), poly(acrylic acid) (PAA), and poly(vinyl acetate) (PVAc). In addition, they prepared the random copolymers PS-co-PMMA and PVC-co-PVAc. In 1986, the BASF Corporation was issued a Canadian Patent for the preparation of polymer powders through the precipitation polymerization of monomers in carbon dioxide at superatmospheric pressures [86], Monomers which were polymerized as examples in this patent included 2-hydroxyethylacrylate and iV-vinylcarboxamides such as iV-vinyl formamide and iV-vinyl pyrrolidone. 

A unique methodology for the generation of nanoporous thin films using supercritical carbon dioxide (SCCO2) for potential nanolithographic applications was introduced in 2004 by Li et al. [53]. In this work, thin films of PS-poly(perfluorooctylethyl methacrylate) [PFMA] were spin-cast onto sili-... 

The non-aqueous system of spherical micelles of poly(styrene)(PS)-poly-(isoprene)(PI) in decane has been investigated by Farago et al. and Kanaya et al. [298,299]. The data were interpreted in terms of corona brush fluctuations that are described by a differential equation formulated by de Gennes for the breathing mode of tethered polymer chains on a surface [300]. A fair description of S(Q,t) with a minimum number of parameters could be achieved. Kanaya et al. [299] extended the investigation to a concentrated (30%, PI volume fraction) PS-PI micelle system and found a significant slowing down of the relaxation. The latter is explained by a reduction of osmotic compressibihty in the corona due to chain overlap. 

Which of the following would you expect might become electrically conductive if doped and why PE, PVC, PS, poly-p-phenylene, and PPV. 

In general, the absorption of smaller molecules such as water acts to decrease the intermolecular forces between chains. Absorption is an attraction property in which likes attract. Thus nonpolar polymers such as PS, poly-... 

When naphthalene is substituted by a polyvinyl aromatic chain polystyrene PS, poly(p-tert-butylstyrene) PTBS or poly(ot-methylstyrene) PMS the course of the metalation is deeply modified (21, 22, 25.). 

One point which can be settled qualitatively, however, is whether singlet exciton migration does in fact occur in the aryl vinyl polymers. It will be shown that available evidence supports energy migration as an important feature of the photophysics of polystyrene (PS), poly(l-vinyl naphthalene) (P1VN), and poly(2-vinyl naphthalene) (P2VN), the homopolymers which are the subject of the majority of the review. 

This is about 1/100 the experimental value of ID/IM = 0.9 recorded for 0.3% P2VN (70,000)/PS (2200) blends. 3<> Thus, there must be some mechanism that increases the probability that an absorbed photon decays from the excimer state, since there are not enough intramolecular EFS to cause such a large value of ID/1M by direct excitation alone. Similar observations were made for dilute miscible PS/Poly(vinyl methyl ether) blends 140). 

Typical photosensitizer (PS) Poly(vinyl cinnamate) (PVCn)... 

Fig. 2.63 Scanning electron micrograph showing a monolayer of pores in a PS-poly(para-phenylene) diblock copolymer film (Widawski et al. 1994). The scale bar represents 20//m.

Fig. 3.6 Sedimentation velocity profiles for PS-poly(4-vinyl-Af-ethylpyridinium bromide) (Mw = 33 kg mol 8% PS) in methanol/34% water/LiBr mixtures at different LiBr concentrations (a) 0.01 M (b) 0.015 M (c) 0.02 M (d) 0.1 M. From Selb and Gallot (1981b).

PS-poly(arylates) Range MEK (selective for PS) Trichloroethanol (selective for poly(arylates)) Measurement of viscosity. Determination of micellar M, A2 and kM. SLS, viscometry, TKM Pavlova et al. (1981)... 

The dependence of the cmc on the length of the insoluble block and its poly-dispersity was calculated, and reasonable agreement with experimental results for the PS-PI/hexadecane (Price etal. 1987) and PS-poly(sodium acrylate)/water systems (Astafieva et al. 1993) were obtained.The cmc was found to decrease as the polydispersity increased, in agreement with the calculations of Linse discussed above.The fraction of dispersed chains and molecular weight distributions of the dispersed chain and the micelles were found to be influenced by the dependence of the cmc of each component in the polydisperse mixture on the insoluble block length (Gao and Eisenberg 1993). 

Fig. 3.23 Coronal thickness, A a. plotted as a function of NX fv f°r micelles formed by PS-poly(2-cinnamoylethyl metharylate) diblocks in cyclopentane (Tao et at. 1997). This yields a straight line in accord with the predictions of scaling theory for the micellar radius (the core radius for these micelles was small enough to be neglected, then RA - R).

Fig. 3.24 Micellar core radius, RB, as a function of Ng for PS-poly(caesium acrylate) (A) and PS-poly(caesium methacrylate) ( ) in toluene (Nguyen el al. 1994). A linear relationship is anticipated by the scaling theories of Zhulina and Birshtein (1985) and Halperin (1987,1990) for type IV micelles.

Fig. 3.29 Dependence of (a) apparent molecular weight, (b) sedimentation coefficient and (c) intrinsic viscosity fi/, and Huggins coefficient, ktl. on solvent composition (methanol-water-0.1 M LiBr mixtures) for solutions of a PS-poly(4-vinyl-A -ethylpyri-dinium bromide) = 32.7kgmol l, 8% PS) diblock (Selb and Gallot 1981a).

Chu and co-workers have also made extensive use of dynamic light scattering to study micellization in PEO/PPO triblocks. This work is discussed in Section 3.3.2 and reviewed by Chu and Zhou (1996), and we do not repeat details here. In addition, temperature-dependent micellization in solutions of a PS-poly (ferf-butylstyrene) (PlBS) diblock and PtBS-PS-PtBS triblock in dimethylac-etamide has been probed using this technique by Chu and co-workers (Zhou et al. 1993, 1995). Booth and co-workers use DLS routinely in their studies of PEO-PBO copolymers, as also discussed in Section 3.3.2 and reviewed by Booth et al. (1997). 

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