Polycarbonate atactic

Glassy amorphous polymers exhibit excellent dimensional stability and are frequently transparent. Everyday examples include atactic polystyrene, polycarbonate, and polymethylmethacrylate (Plexiglas ), which we encounter in such applications as bus shelters, motorcycle windshields, and compact disc cases. 

Although it is called crystal clear polystyrene, atactic PS is amorphous and clear, as are PMMA and polycarbonate (PC). In contrast, hdpe and nylon 66 are highly crystalline and opaque. The relationship of packing efficiency to specific gravity and crystallinity is readily illustrated by ldpe and HDPE, which are 60 and 95% crystalline, respectively, and have specific gravities of 0.91 and 0.97, respectively. 

ABA ABS ABS-PC ABS-PVC ACM ACS AES AMMA AN APET APP ASA BR BS CA CAB CAP CN CP CPE CPET CPP CPVC CR CTA DAM DAP DMT ECTFE EEA EMA EMAA EMAC EMPP EnBA EP EPM ESI EVA(C) EVOH FEP HDI HDPE HIPS HMDI IPI LDPE LLDPE MBS Acrylonitrile-butadiene-acrylate Acrylonitrile-butadiene-styrene copolymer Acrylonitrile-butadiene-styrene-polycarbonate alloy Acrylonitrile-butadiene-styrene-poly(vinyl chloride) alloy Acrylic acid ester rubber Acrylonitrile-chlorinated pe-styrene Acrylonitrile-ethylene-propylene-styrene Acrylonitrile-methyl methacrylate Acrylonitrile Amorphous polyethylene terephthalate Atactic polypropylene Acrylic-styrene-acrylonitrile Butadiene rubber Butadiene styrene rubber Cellulose acetate Cellulose acetate-butyrate Cellulose acetate-propionate Cellulose nitrate Cellulose propionate Chlorinated polyethylene Crystalline polyethylene terephthalate Cast polypropylene Chlorinated polyvinyl chloride Chloroprene rubber Cellulose triacetate Diallyl maleate Diallyl phthalate Terephthalic acid, dimethyl ester Ethylene-chlorotrifluoroethylene copolymer Ethylene-ethyl acrylate Ethylene-methyl acrylate Ethylene methacrylic acid Ethylene-methyl acrylate copolymer Elastomer modified polypropylene Ethylene normal butyl acrylate Epoxy resin, also ethylene-propylene Ethylene-propylene rubber Ethylene-styrene copolymers Polyethylene-vinyl acetate Polyethylene-vinyl alcohol copolymers Fluorinated ethylene-propylene copolymers Hexamethylene diisocyanate High-density polyethylene High-impact polystyrene Diisocyanato dicyclohexylmethane Isophorone diisocyanate Low-density polyethylene Linear low-density polyethylene Methacrylate-butadiene-styrene... 

Morphology, Viscoelastic Properties, and Stress-Strain Behavior of Blends of Polycarbonate of Bisphenol-A (PC) and Atactic Polystyrene (PST)... 

Materials. Polycarbonate of Bisphenol-A(PC) was a commercial product (Lexan, General Electric Co., U.S.A.), with a viscosimetric average molecular weight Mv = 40,000. High molecular-weight atactic polystyrene (Mv == 280,000) was obtained from Schuchardt, Miinchen. 

In the literature there are reports of radial distribution function analyses performed with polystyrene,6 7 polycarbonate of bisphenol-A,7 8 and a number of other amorphous polymers.9 As an illustration, we present results obtained with atactic polystyrene. Figure 4.2 shows the x-ray scattering intensity data obtained with CuKa radiation. The strong peak at 26 around 20° represents the so-called amorphous halo, whereas the smaller peak at around 10° is called the polymerization peak by some and has attracted interest with regard to its structural origin. The experimentally measured intensity is first corrected for background, polarization, absorption, etc.,... 

Films made of atactic polystyrene (PS Asahi Dow, Japan), bisphcnol-A polycarbonate (PC Teijin Kawi, Japan) and nylon 6 (Ube Kosan, Japan) were used for plasma treatment. Both PS and PC films were prepared by melt-pressing and slow cooling, and nylon 6 film was prq>a(ied by mch-pressing and quenching. Balance-type commercial nyltn 6 film (Unitika, Japan) was also u. ... 

A material that solidifies from the molten state without crystallization, a supercooled liquid whose shear viscosity is t > 10 Pas, a liquid whose rigidity is great enough to be put to use, or a glassy state of matter. A typical glassy material is hard and brittle (tensile modulus E 70 GPa, tensile strength a 0.5 GPa). Typical polymeric glasses are atactic polystyrene, atactic polymethylmethacrylate, polycarbonate, etc. 

Fig. 5. Boson peak energy as a function of monomer mass for amorphous polymers and as a function of molecular mass for organic molecular glasses. Amorphous polymers polyethylene (PE) [29], poly(vinyl alcohol) (PVA) [152], cis-1,4-polyhutadiene (PB), polyisobutylene (PIB), frans-1,4-polychloroprene (PCP), atactic polyst ene (PS), atactic poly(methyl methacrylate) (PMMA), poly(ethylene terephthalate) (PET) [30, 34], atactic polypropylene (a-PP) [95],polyisoprene with deuteratedmethyl group (PIP-dj) [36],polycarbonate (PC) [91],polyimide (AURUM) [39]. Molecular glasses propylene (P), 1-butene (B), 3-methyl pentane (MP),ortho-terphenyl (OTP),ethylbenzene (EB) [38]...

The possible effect of spatial order on carbazole groups has been a subject of discussion. Isotactic poly[2-(N-carbazolyl)ethyl acrylate] exhibits a room-temperature hole mobility of 1.7 x 10 m V s at 2xlO Vm which is considerably higher than that of the atactic polymer or PVK [80]. On the other hand, these values are very close to those obtained for NIPC/polycarbonate at a comparable concentration of the transport-active molecule, i.e, a system with no order. Experiments with other carbazole polymers have shown that changing the backbone (e.g. carbon vinyl to siloxy) [45], or spacing of carbazole groups from the chain, has only a secondary effect. 

Blends of PMMA and polycarbonate based on hexafluoroBisphenol A (HFPC) were noted to be miscible as well as blends of PC copolymers based on HFBisphenol A and Bisphenol A PC [437]. Additionally, HFPC exhibited miscibility with PEMA and PnPMA. Bisphenol chloral polycarbonate (BCPC) exhibited miscibility only with PMMA. The effect of tacticity of PMMA was reported [438] on phase behavior with PC blends. Miscibility was shown to increase in PC blends in the order of atactic, isotactic, syndiotactic, with syndiotactic PMMA/PC showing no thermally induced phase separation up to 300 °C. 

I have looked at the effect of tacticity on poly(methyl methacrylate). I think in general, in actual fact, it is remarkably insensitive, and I ve looked at heterotactic, syndiotactic, and atactic systems, and there are differences which one can relate to the tacticity. In general, I think of the effect of densification as being fairly small except in some particular cases, of which polycarbonate is one. 

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