Handbook of Polymer Synthesis Second Edition Episode 14 pptx

... ratio of about 0.4 and an average degree of polymerization of about 30 [43]. ð12Þ Phenylic substituents at the vinyl ene positions — increasing both solubi lity of the polymer and stability of the ... synthesis of polyfluoren homopolymers allows also the design of alternating copolymers. Instead of the 2,7-dibromofluorene a variety of dibromoarenes can be used in the Pd-ca...

Ngày tải lên: 13/08/2014, 16:21

... discussion of hyperbranched polymers will be presented in a separate chapter of this handbook. D. Unusual Synthetic Methods The discussion of unusual methods reported for syntheses of PEKs is ... interesting group of polymers. Two precursor routes were recently explored. Firstly, synthesis of PEKs having pendant t-butyl groups [194, 214, 215] which can be eliminated as isobuty...

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... number of macrocycles n (degree of polymerization) with the number of bridged monomers b and the number of end monomers e. n ¼ b=2 þ e=4 ð9Þ Evaluation of some data (determination of number of nitrile ... and polymeric phthalocya- nines. By ESCA spectra 0.7% of free Cu in the polymeric films were found. In dependence of the deposited Cu-film thicknesses of 1.5 till 20 nm a...

Ngày tải lên: 13/08/2014, 16:21

... Synthesis of Conducting Polymers in Handbook of Conducting Polymers, Vol. 1 (Skotheim, T. A., ed.), Marcel Dekker, New York, p. 82; Street, G. B. (1986). From Powder to Plastics in Handbook of ... as an organic polymer coating. The performance of layered semiconductors has been shown to be improved by the electropolymerization of layers of poly(indole) on the defective sit...

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... is CatÀM 1 polymer þ M 1 À! k 11 CatÀM 1 ÀM 1 polymer ð32Þ CatÀM 1 polymer þ M 2 À! k 12 CatÀM 2 ÀM 1 polymer ð33Þ CatÀM 2 polymer þ M 1 À! k 21 CatÀM 1 ÀM 2 polymer ð34Þ CatÀM 2 polymer þ ... comonomer, as it promotes the polymer s degradability in the presence of light [182]. As a consequence of the diversified nature of the comonomers, a large number of variants of...

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... conditions of radical-induced vinyl polymerization (e.g., the rate of polymerization was found to be proportional to the square root of the initiator concentration). However, the average degree of polymerization ... of phenol and acetone by the cumene oxidation process. The polymerizat ion characteristics of a-methylstyrene are considerably different from those of styrene. Wherea...

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... course of the polymerization [247–249]. Particularly attractive aspects of this technique of radiation polymerization are the excellent efficiency of polymerization together with the high rates of polymerization ... the degree of polymerization should be a function of the number of polymer lattices and initiator con centration. However, for the polymeri- zation of VC in emul...

Ngày tải lên: 13/08/2014, 16:21

... kind of polymerization is often limited by the occurrence of side reactions, including (1) the attack of the initiator at the carbonyl double bond of the monomer or polymer, (2) chain transfer of ... preparation of ABA block copolymers when bifunctional initiators are used, whereas the first method enables the synthesis of triblock copolymers by addition of the first monomer...

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... rings: ð64Þ At a polymerization temperature of 22  C, approximately 80% of the cyclopentane rings in the polymer are trans. Table 23 shows some other examples of the polymerization of nonconjugated ... coordination of the monomer occurs with only one double bond for both isomers of pentadiene. In the presence of CrO 3 only the trans-isomer of pentadiene is polymerized to a...

Ngày tải lên: 13/08/2014, 16:21

... successful polymerizations of monomers with, e.g., cyano [59 ,142 ], ester [59 ,142 ], carboxylic acid anhydride [143 ], amide [144 ] and ether [59] functionalities were reported [20]. The addition of aldehydes ... predictions [267]. These secondary metathesis reactions of course may also affect the microstructure of the polymers, e.g., the fraction of cis double bonds [275,283]. The...

Ngày tải lên: 13/08/2014, 16:21