scispace - formally typeset
Search or ask a question
Topic

Polycarbonate

About: Polycarbonate is a research topic. Over the lifetime, 14032 publications have been published within this topic receiving 141740 citations. The topic is also known as: PC & Polycarbonate, PC.


Papers
More filters
Patent
12 Jan 2001
TL;DR: In this article, a method for preparing polycarbonates, which utilizes polycondensation catalysts which are salts of certain phenanthroline compounds, was presented, and it was found that this new class of catalysts provided excellent polymerization rates for the preparation of Bisphenol A polycarbonate from the melt polymerization of diphenyl carbonate.
Abstract: This invention provides a method for preparing polycarbonates, which utilizes polycondensation catalysts which are salts of certain phenanthroline compounds. We have found that this new class of catalysts provide excellent polymerization rates for the preparation of Bisphenol A polycarbonate from the melt polymerization of diphenyl carbonate and Bisphenol A. Moreover, the catalysts of the invention were found to be very selective in substantially reducing the level of branching side reaction, i.e., formation of Fries product, normally associated with the melt polycarbonate process.

62 citations

Journal ArticleDOI
TL;DR: In this paper, an innovative one-dimensional photonic bandgap structure on plastic substrate, for electromagnetic field shielding applications in the radio frequency range, was presented, from material characterization and design, to fabrication and experimental test of a prototype sample consisting of seven alternating zinc oxide and silver (Ag) layers, on Lexan polycarbonate.
Abstract: The aim of this paper is to present an innovative one-dimensional photonic bandgap structure on plastic substrate, for electromagnetic field shielding applications in the radio frequency range. A complete study is performed, from material characterization and design, to fabrication and experimental test of a prototype sample consisting of seven alternating zinc oxide and silver (Ag) layers, on Lexan polycarbonate. The transparent metal is designed to obtain high shielding effectiveness (SE), not just as a theoretical prediction, but as experimentally measured according to the standard ASTM-D 4935/89. Actually, the shielding performance of multilayered coatings having similar values of sheet resistance but different design are strongly affected by the bonding conditions. The following properties of the structure, which contains only 66 nm of Ag, are highlighted: 1) it remains transparent in the visible range; 2) it retains the conductivity of bulk metal; 3) it has SE in the 30-kHz to 1-GHz range over 40 dB; 4) the overall thickness of the multilayer shielding coating is 312 nm; and 5) it has been realized on both glass or plastic substrate.

62 citations

Journal ArticleDOI
TL;DR: In this article, the role of ester-carbonate interchange reactions during melt mixing was experimentally examined and found to be unimportant, from which it was concluded that the observed miscible phase formation is due to physical interactions between the blend components.
Abstract: Melt blends of polycarbonate with Kodel, a homopolyester formed from 1,4-cyclohexanedimethanol and terephthalic acid, and with Kodar, a copolyester formed by replacing some of the terephthalic acid with isophthalic acid, were prepared and their transitional behavior were examined by thermal analysis and dynamic mechanical testing. Blends formed with either polyester were found to have a single Tg over the entire compositional range. Single composition-dependent α- and β-relaxation temperatures were also observed for blends made with either polyester at all compositions. From these data it is concluded that both Kodel and Kodar blends with polycarbonate form miscible amorphous phases. The role of ester–carbonate interchange reactions during melt mixing was experimentally examined and found to be unimportant, from which it is concluded that the observed miscible phase formation is due to physical interactions between the blend components.

61 citations

Journal ArticleDOI
TL;DR: The authors examined the influence of film thickness and composition on the effective Tg of compatible thin film mixtures of polystyrene (PS) and tetramethylbisphenol-A polycarbonate (TMPC) on SiOx/Si substrates using spectroscopic ellipsometry.
Abstract: We examined the influence of film thickness and composition on the effective Tg of compatible thin film mixtures of polystyrene (PS) and tetramethylbisphenol-A polycarbonate (TMPC) on SiOx/Si substrates using spectroscopic ellipsometry Our measurements reveal that while the Tg of TMPC films increased with decreasing film thickness, h, the effective Tg of thin film mixtures of PS and TMPC decreased with decreasing film thickness In these mixtures, Tg was independent of film thickness at large h We also found that while the Tg of bulk mixtures of TMPC/PS exhibited large negative deviations from additivity with composition, such deviations were negligible in the thin film mixtures The thickness dependence of Tg is compared with theory

61 citations

Journal ArticleDOI
TL;DR: In this article, the glass transition temperature Tg of polycarbonate ultrathin films was investigated as a function of film thickness from 22 to 350 nm and over a range of cooling rates from 0.1 to 1000 K/s.
Abstract: Flash differential scanning calorimetry was used to study the glass transition temperature Tg of polycarbonate ultrathin films. The investigation was made as a function of film thickness from 22 to 350 nm and over a range of cooling rates from 0.1 to 1000 K/s. Polycarbonate spin cast films were floated on a layer of grease on the calorimetric chip. The results show a greatly reduced glass temperature for the thinnest films relative to the macroscopic value. We also observed that the magnitude of the glass temperature reduction decreases as the cooling rate increases with the highest cooling rates showing little thickness dependence of the Tg. Dynamic fragility and activation energy at Tg were found to decrease with decreasing film thickness. The results are discussed in the context of literature reports for supported and freely standing polycarbonate films. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1462–1468

61 citations


Network Information
Related Topics (5)
Polymer
131.4K papers, 2.6M citations
93% related
Polymerization
147.9K papers, 2.7M citations
91% related
Amorphous solid
117K papers, 2.2M citations
84% related
Carbon nanotube
109K papers, 3.6M citations
84% related
Oxide
213.4K papers, 3.6M citations
83% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023248
2022471
2021184
2020294
2019390
2018403