Polyolefins resins

Electrical Properties. AH polyolefins have low dielectric constants and can be used as insulators in particular, PMP has the lowest dielectric constant among all synthetic resins. As a result, PMP has excellent dielectric properties and alow dielectric loss factor, surpassing those of other polyolefin resins and polytetrafluoroethylene (Teflon). These properties remain nearly constant over a wide temperature range. The dielectric characteristics of poly(vinylcyclohexane) are especially attractive its dielectric loss remains constant between —180 and 160°C, which makes it a prospective high frequency dielectric material of high thermal stabiUty. 

Analytical and test methods for the characterization of polyethylene and PP are also used for PB, PMP, and polymers of other higher a-olefins. The C-nmr method as well as k and Raman spectroscopic methods are all used to study the chemical stmcture and stereoregularity of polyolefin resins. In industry, polyolefin stereoregularity is usually estimated by the solvent—extraction method similar to that used for isotactic PP. Intrinsic viscosity measurements of dilute solutions in decahn and tetraHn at elevated temperatures can provide the basis for the molecular weight estimation of PB and PMP with the Mark-Houwiok equation, [rj] = KM. The constants K and d for several polyolefins are given in Table 8. 

In particular, PB and PMP are inert materials and usually present no health hazard. PMP is employed extensively for a number of medical and food packaging appHcations. Several grades conform to FDA regulations and to the health standards of other countries. Flammability of polyolefin resins is equal to that of PP, around 2.5 cm /min (ASTM D635). However, during combustion or pyrolysis, smoke, fumes, and toxic decomposition products are formed and can pose a health hazard. 

Recommended for use as coupling agents are monoalkoxytriacyl titanates, such as isopropoxytriisostearyl titanate, Ken-React KR TTS or TYZOR ISTT [61417-49-0] which are useflil in mineral-filled polyolefin resins (526) chelated titanates, such as di(dioctyl)pyrophosphatooxoethylene titanate,... 

NACE Recommended Practice RP-02-75, Application of Organic Coatings to the External Surface of Steel Pipe for Underground Service NACE Recommended Practice RP-08-85, Extruded Polyolefin Resin Coating Systems for Underground or Submerged Pipe... 

Wet processes involve mixing a hydrocarbon liquid or some other low-molecular -weight substance with a polyolefin resin, heating and melting the mixture, extruding the melt into a sheet, orientating the sheet either in the machine direction or biaxi-ally, and then extracting the liquid with a volatile solvent [6-8]. 

Dry processes involve melting a polyolefin resin, extruding it into a film, thermal annealing, orientation at a low temperature to form micropore initiators, and then orientation at a high temperature to form micropores [9, 10]. The dry process involves no solvent handling, and therefore is inherently simpler than the wet process. The dry process involves only virgin polyolefin resins and so presents little possibility of battery contamination. 

Traditionally carpet tile backings have been made from bitumen, PVC or polyurethane. There are problems with the environmental impact of these materials and they are difficult to recycle. Shaw industries developed their EcoWorx carpet tile backing using a polyolefin resin. This has superior environmental profile to PVC and is easier to recycle than bitumen and the cross-linked polyurethane backings. EcoWorx has lower toxicity, better adhesion and good dimensional stability. It is easy to recycle and can be separated from any fibre type used in the carpet tile. It works particularly well with nylon-6 fibres. EcoWorx tiles contain 40% recycled content and Shaw have established a collection and return scheme to close the loop. 

Many of the geometric features of a VBFT screw are similar to those for an FT screw. The VBFT screw, however, has three additional enhanced features that can be adjusted for optimal processing performance. The channel depths for a 114.3 mm diameter VBFT screw designed for use with a specific polyolefin resin is shown by... 

Shaw selected a combination of polyolefin resins as the base polymer of choice for its substitute, EcoWorx . Due to the low toxicity of its feedstocks, superior adhesion properties, dimensional stability, and its ability to be recycled, EcoWorx meets all of the design criteria necessary to satisfy the needs of the marketplace from a performance, health, and environmental standpoint. Research also indicated that the post-consumer carpet tile had a positive economic value at the end of its useful life. The cost of collection, transportation, elutriation, and return to manufacturing processes is less than the cost of using virgin raw materials. This is a truly recyclable (or Cradle to Cradle) product and is a good example of how substitution through innovation can make economic as well as environmental sense. ... 

The process for making lithium-ion battery separators can be broadly divided into dry - and weH processes. Both processes usually employ one or more orientation steps to impart porosity and/or increase tensile strength. The dry process involves melting a polyolefin resin, extruding it into a film, thermally... 

Uses. Solvent for polymers polymerization catalyst stabilizer against thermal degradation in polystyrene UV stabilizer in polyvinyl and polyolefin resins... 

Patent Number US 5859076 A 19990112 OPEN CELL FOAMED ARTICLES INCLUDING SILANE-GRAFTED POLYOLEFIN RESINS... 

Describes open cell foamed articles including silane-grafted single-site initiated polyolefin resins. The olefin polymer resin can be a polyethylene, a copolymer of ethylene, a C3-C20 alpha-olefin, or a copolymer of ethylene, a C3-20 alpha-olefin and a C4-C20 diene. The open cell foamed articles have good cushioning properties and can be non-allergenic. 

An integrally monlded composite article comprised of (I) a nonfoam layer formed from a thermoplastic elastomer powder composition (A) and (II) a foam layer formed from a foamable composition comprised of (i) (B) a thermoplastic synthetic resin powder, and (C) a heat decomposable foaming agent and (D) a liquid coating agent, wherein the thermoplastic elastomer powder (A) is comprised of a composition of an ethylene-alpha-olefm copolymer mbber and a polyolefin resin or thermoplastic elastomer powder comprised of a partially crosslinked composition of an ethylene-alpha-olefm copolymer mbber and a polyolefin resin, the thermoplastic elastomer powder having a complex dynamic viscosity at 250 deg C and a freqnency of 1 radian/sec of not more than 1.5x1,000,000 poise and having a Newtonian viscosity index n, calculated by a specific formula. 

Patent Number US 5091435 E 19940510 CROSS-LINKABLE FOAMABLE POLYOLEFIN RESIN COMPOSITION... 

Patent Number US 5304580 A 19940419 EXPANDABLE POLYOLEFIN RESIN COMPOSITIONS... 

R.W. Baker and M.L. Jacobs, Improve Monomer Recovery from Polyolefin Resin Degassing, Hydrocarbon Process. 75, 49 (1996). 

Baker, R.W. and Jacobs, M. (1996) Improved monomer recovery from polyolefin resin degassing. Hydrocarbon Processing, 75(3), 49. 

Tokoro, H. Tsurugai, K. Shioya, S. Oikawa, M. Flame-retardant foamed particles of polyolefin resin. PCT US Patent 5,569,681 assigned to JSP Corporation, 1996. 

Stuart, J.B. Skarke, S.C. Ogita, T. et al. Flame retardant polyolefin resin pre-expanded particles and in-mold foamed articles prepared therefrom, PCT US Patent 6,822,023 assigned to Kaneka Corporation, 2001. 

The surfaces of the items may be primed by applying adhesion promoters, which are chlorinated polyolefin resins dissolved in xylene—again, however, subject to careful control as in (i). 

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