"Ethylene Copolymers". In: Encyclopedia of Polymer Science
heterogeneous polymers consisting of mixtures of copolymers and homopolymers ..... Engineering stressâstrain data (23â¦C, 5.7 minâ 1) for ethylene-co-styrene.
ETHYLENE COPOLYMERS Introduction Polyethylene and polystyrene are two high volume commodity polymers, widely studied in materials research, exemplifying the classes of semicrystalline polymers (qv) and amorphous polymers (qv) respectively (see ETHYLENE POLYMERS, HDPE; STYRENE POLYMERS). There has been considerable interest to produce copolymers from ethylene (E) and styrene (S). The incorporation of aromatic groups in polyethylene has been associated, for example, with enhanced radiation resistance (1) or electrical-breakdown resistance by enabling space charge dissipation (2). A variety of different copolymer molecular architectures can potentially be produced. In addition to the different comonomer distributions (random, alternating, or blocky nature), there are possibilities for chain branching and stereoregularity in the copolymer chain microstructure. Various references describe efforts to copolymerize ethylene and styrene. The production of copolymers has been attempted by using conventional polymerization routes for either polyethylene or polystyrene with introduction of the alternate comonomer into the process. Many reported copolymerizations produce heterogeneous polymers consisting of mixtures of copolymers and homopolymers (3), for example U.S. patent number 3,117,945 describes the production of a “gross” copolymer, composed of various fractions that could be separated on the basis of their solubility parameter. Copolymers containing low levels (
A relatively new type of metallocene- catalyzed polyethylene, here noted as mPE. â. , is shown to have higher melt viscosity than LLDPE at very low shear rates ...
A graft copolymer with one branch can be considered as a miktoarm ...... stress at break, toughness and yielding stress for poly(butyl ... graft copolymers were found to increase, whereas yield elongation decreased as ... Stress at break, MPa. Y oung
MD. 62. 35. 54. 131. 143. XD. 43. 39. 131. 226. 309. Tensile strength, MPac. D882. MD. 20. 19. 35. 36. 45 ..... R CH2R + R·âRH + R C·HR. (16) ...... D. E. Axelson, G. C. Levy, and L. Mandelkern, Macromolecules 12, 41 (1979). 29. J. C. Randall ...
weight distribution is measured by gel-permeation chromatography (gpc). Short-Chain ..... Vapor from the flash step is condensed, cooled, and returned.
terification process and the polycarbonate product so formed (11). ..... have been invoked as mechanisms for energy absorption, providing .... bonate exhibits excellent thermal stability, especially in the absence of oxygen ... Visible light transmis
types of polymers. The transport properties of glassy and rubbery polymers are related to their ... Encyclopedia of Polymer Science and Technology. Copyright John ...... J. R. Fried, M. Sadat-Akhavi, and J. E. Mark, J. Membr. Sci. 149(1), 115 ...
The polymers known as polyurethanes include materials that incorporate ... and excellent processibility, but limited thermal stability (owing to their thermo- plasticity). Thermoset ... propylene oxides provided the foam manufacturers with a broad ch
Oxidative polymerization is, formally, abstraction of two hydrogen atoms from a ..... polyphenol was obtained for the first time by controlling the polymer structure ..... presence of a strong acid by electrolysis (198) and by reaction with Lewis ...
Tensile mode illustrated with wire-mesh cut at 45⦠bias to minimize shear resistance of mesh. Fig. 18. .... C), such as methanol. It was speculated that .... tronic sensor, a low cost, on-line approach sensitive to refractive index variation, for c
In solution or at the end of emulsion polymerization, tetraalkyl thiuram disulfides .... providing increased strength to vulcanizates used as mechanical goods. ...... of elasticity of such films decreases further on continued exposure to heat. .....
also used for coatings, in electrical insulation for high temperature service, and ... An all aromatic polyetherimide is made by DuPont from reaction of pyromel-.
cialization of this polymer. .... sorption is generally concentrated in the amorphous regions of the polymer ...... Chemicals Association, Lancaster, Pa., 1999. 21.
stitution in the presence of a Lewis acid (27) or by metallation of a ...... P. H. Toy, T. S. Reger, P. Garibay, J. C. Garno, J. A. Malikayil, G. Liu, and K. Janda,.
Vol. 1. BLOCK COPOLYMERS, TERNARY TRIBLOCK. 493 by the fields WA and WB ...... It has been predicted that a strongly interacting endblock can also mod-.
Gases and vapors permeate FEP resin at a rate that is considerably lower than that of most plastics. Because FEP resins are melt processed, they are void-free ...
1999 were about 5.7 Ã 106 m3, having a value of $18 billion (1). Coatings are ... erties. A problem with thermosetting systems is the relationship between stability ... Design of stable coatings that cure at lower temperatures or shorter times .....
Bismuth oxychloride pigment is the closest to natural pearl but is fragile and has relatively poor ..... Molybdates and vanadates are often used as catalysts for.
tunistic pathogens (eg, herpes simplex virus and cytomegalovirus) in immuno- ...... J.-C. Lee, M. H. Litt, and C. E. Rogers, Macromolecules 30, 3766 (1997). 21.
include the fact that it is a liquid polymer, and so it does not require a solvent ..... by the APA-Engineered Wood Association as the APA-Engineered Wood ...
to proteins in natural latex and other natural latex market drivers have recently ... Traditional applications for latices are adhesives, binders for fibers and ...... (132). Sometimes skewed monomer feeds are used to offset differences in monomer ..
raised by porosity and decreased by surface oxygen or adsorbed organics. ...... nents and in containers and pipes for combustible liquids such as gasoline. The.
as templates, are proposed to assist the orientation of lignin precursors to afford ...... Additional large-volume uses of lignosulfonates include animal feed pellet ... development efforts have resulted in specialty uses in several key market ... us