Results 111 to 120 of about 5,022 (153)

Star and Hyperbranched Polyisobutylenes via Terminally Reactive Polyisobutylene‐Polystyrene Block Copolymers

Macromolecular Symposia, 2013
AbstractUnique, highly branched polyisobutylenes (PIB) were prepared via quasiliving carbocationic copolymerization of isobutylene and styrene (St) monomers. The junction points were formed by Friedel‐Crafts self alkylation of PSt segments by the carbocationic chain ends. First, linear PIB was prepared with reactive chain ends. This was reacted with St
Kali, Gergely, Szesztay, Andrásné, Bodor, Andrea, Iván, Béla   +3 more
openaire   +1 more source

Functionalization of polyisobutylene and polyisobutylene oligomers via the ritter reaction

Journal of Polymer Science Part A: Polymer Chemistry, 2018
ABSTRACTThe Ritter reaction, that is, reaction of a carbocation with a nitrile, was carried out on polyisobutylene (PIB) using a variety of reaction conditions. End quenching of PIB carbocations with acrylonitrile under living polymerization conditions (methyl chloride (MeCl)/hexane 60/40 (v/v) solvent mixtures at −70 °C) resulted in either tert ...
Corey M. Parada, Robson F. Storey
openaire   +2 more sources

Complex Dynamics in Polyisobutylene Melts

Macromolecules, 2002
The dynamics of polyisobutylene at 407 K is investigated by means of quasi-elastic neutron scattering. By proper data reduction, data from two different instruments were combined to provide the incoherent intermediate scattering function, I-s(Q,t), over 3 decades in time.
Triolo A, Lechner RE, Desmedt A, Telling MTF, Arrighi V   +4 more
openaire   +3 more sources

Viscous Properties of Polyisobutylene

Physics, 1935
The viscosity of polyisobutylene (molecular weight about 4900) has been studied from 70°C to 175°C with a falling sphere viscometer and from −53°C to 24°C with a concentric cylinder viscometer. In the measurements with the latter apparatus, elastico-viscous effects appeared, and the viscous behavior was non-Newtonian.
John D. Ferry, George S. Parks
openaire   +1 more source

Polyisobutylene-Based Thermoplastic Elastomers. I. Synthesis and Characterization of polystyrene-Polyisobutylene-Polystyrene Triblock Copolymers

Journal of Macromolecular Science, Part A, 1994
Abstract Polystyrene-polyisobutylene-polystyrene triblock copolymer thermoplastic elastomers have been synthesized by living carbocationic sequential copolymerization using the tert-butyl dicumyl chloride/TiCl4/methylcyclohexane:methyl chloride (60:40 v:v)/ −80°C system in the presence of the proton trap 2,6-di-tert-butylpyridine.
Miklos Gyor, Zsolt Fodor, Hsien-Chang Wang, Rudolf Faust   +3 more
openaire   +1 more source

Halogen-free polyisobutylene by in situ methylation of living polyisobutylene using dimethylzinc

Polymer Bulletin, 2000
Halogen-free polyisobutylene (PIB) was synthesized by in situ methylation of living PIB using dimethylzinc. Quantitative methylation of living PIB was achieved within 60 min using a ratio of [(CH 3 ) 2 Zn]/[TiCl 4 ] 0 = 1 without any side reactions. Under similar conditions, living PIB capped with 1,1-diphenylethylene (PIB-DPE + ) yielded close to 1:1
Young Cheol Bae, Il-Jin Kim, Rudolf Faust   +2 more
openaire   +1 more source

Hierarchically Mesostructured Polyisobutylene‐Based Ionic Liquids

Macromolecular Rapid Communications, 2016
The formation and design of a hierarchically nanostructured poly(isobutylene)‐based ionic liquid (PIB‐ILs) is reported, displaying assembly into classical multiplets and an additional ordering of the aromatic counteranions. Three PIB‐ILs (Mn = 3600 and 8600 g mol−1), bearing imidazolium (1a), N‐methylpyrrolidinium (1b), and triethylammonium cations (1c)
Appiah, Clement, Akbarzadeh, Johanna, Stojanovic-Marinow, Anja, Peterlik, Herwig, Binder, Wolfgang H.   +4 more
openaire   +2 more sources

Crystal structure of polyisobutylene

Journal of Polymer Science: Polymer Physics Edition, 1974
AbstractThe crystal structure of polyisobutylene was determined by x‐ray analysis. The orthorhombic cell, with a = 6.88 Å, b = 11.91 Å, c (fiber axis) = 18.60 Å (space group: P212121 − D), contains two molecular chains each consisting of eight monomeric units in the fiber identity period.
Tamotsu Tanaka, Yozo Chatani, Hiroyuki Tadokoro   +2 more
openaire   +1 more source

Conformational characteristics of polyisobutylene

Macromolecules, 1983
Energies de conformation de composes modeles et de segments d'une chaine de polyisobutene contenant jusqu'a 6 unites ...
U. W. Suter, Enrique Saiz, Paul J. Flory
openaire   +1 more source

Macromolecular Compounds. CCXCII Polyisobutylene

Rubber Chemistry and Technology, 1944
Abstract An explanation of the chemical constitution of macromolecular substances has to a great extent been made possible by the preparation and study of various homologous series of polymers. In these investigations, the relations between the average degrees of polymerization and the physical properties of the particular substances concerned ...
H. Staudinger, G. Bebger, Kl. Fischer
openaire   +1 more source