Polyolefins and Copolymers

Chang, S.S., Senich, G.A. and Smith, L.E. 1982, Migration of Low molecular weight Additives in Polyolefins and Copolymers, Final Report, NBS1R 82-2472, National Institute for Standards and Technology, Washington, DC. 

Recently, much attention has been devoted to modeling polyolefins and copolymers of ethylene and polar monomers. Eor example, polymers with regularly spaced methyl groups on a polyethylene backbone have been synthesized and display very interesting and surprising thermal properties and microstructure [12]. This represents a rational synthesis of branched polyethylene that cannot be achieved by any other means at this time (Scheme 6.12). 

Describe the high-pressure binary and ternary polyolefin and copolymer (poly(ethyl-ene-co-propylene)) systems... 

Properties M.w. 943.62 sp.gr. 2.17 m.p. 95 C Toxicology LD50 (oral, mouse) > 20,000 mg/kg, (dermal, mouse) > 20,000 mg/kg Uses Flame retardant used in polybutylenes, polyolefins and copolymers, wire insulation, textiles... 

State with the coexistence of isotropic and anisotropic phases. In some cases, the occurrence of miscibility phenomena in the melt has been observed, due to the presence of chemical and/or specific interactions between the polymer components [135], For blends of LCP with polyolefins, such as PE or PP, due to the different chemical nature of these polymers, compatibilization with modified polymers is required to improve the adhesion and mechanical properties. Several functionalized polyolefins and copolymers (PP-g-MA, PP-AA, E-GMA) [136], as well as polyolefin-LCP graft copolymers (PE-g-SBH, PP-g-SBH) synthesized by melt polycondensation, have been used [137,138]. 

Other Polymers. Besides polycarbonates, poly(methyl methacrylate)s, cycfic polyolefins, and uv-curable cross-linked polymers, a host of other polymers have been examined for their suitabiUty as substrate materials for optical data storage, preferably compact disks, in the last years. These polymers have not gained commercial importance polystyrene (PS), poly(vinyl chloride) (PVC), cellulose acetobutyrate (CAB), bis(diallylpolycarbonate) (BDPC), poly(ethylene terephthalate) (PET), styrene—acrylonitrile copolymers (SAN), poly(vinyl acetate) (PVAC), and for substrates with high resistance to heat softening, polysulfones (PSU) and polyimides (PI). 

The use of TAG as a curing agent continues to grow for polyolefins and olefin copolymer plastics and mbbers. Examples include polyethylene (109), chlorosulfonated polyethylene (110), polypropylene (111), ethylene—vinyl acetate (112), ethylene—propylene copolymer (113), acrylonitrile copolymers (114), and methylstyrene polymers (115). In ethylene—propylene copolymer mbber compositions. TAG has been used for injection molding of fenders (116). Unsaturated elastomers, such as EPDM, cross link with TAG by hydrogen abstraction and addition to double bonds in the presence of peroxyketal catalysts (117) (see Elastol rs, synthetic). 

Chisso-Asahi Fertilizer Company, Ltd. This company utilizes thermoplastic resins, such as polyolefins, poly(vinyhdene chloride), and copolymers, as their coating materials. The coatings are dissolved in fast-drying chlorinated hydrocarbon solvents and are appHed to a variety of substrates including urea, diammonium phosphate [7783-28-0] potassium sulfate [7778-80-3], potassium chloride [7447-40-7], and ammonium nitrate/potassium sulfate-based N—P—K fertilizers. 

With most homopolymers and copolymers the apparent viscosity is less dependent on temperature and shear stress (up to 10 dyn/cm ) than that of the polyolefins, thus simplifying die design. On the other hand the melt has a low elasticity and strength and this requires that extruded sections be... 

Among the different pressure sensitive adhesives, acrylates are unique because they are one of the few materials that can be synthesized to be inherently tacky. Indeed, polyvinylethers, some amorphous polyolefins, and some ethylene-vinyl acetate copolymers are the only other polymers that share this unique property. Because of the access to a wide range of commercial monomers, their relatively low cost, and their ease of polymerization, acrylates have become the dominant single component pressure sensitive adhesive materials used in the industry. Other PSAs, such as those based on natural rubber or synthetic block copolymers with rubbery midblock require compounding of the elastomer with low molecular weight additives such as tackifiers, oils, and/or plasticizers. The absence of these low molecular weight additives can have some desirable advantages, such as ... 

Eastman, E.F. and Ftillhart, L., Polyolefin and etbylene copolymer-based bol melt adhesives. In Skeist, l.S. (Ed.), Handbook of Adhesives. 3rd edn. Van Nostrand Reinhold, New York, 1990, p. 408. 

Blends based on polyolefins have been compatibilized by reactive extrusion where functionalized polyolefins are used to form copolymers that bridge the phases. Maleic anhydride modified polyolefins and acrylic acid modified polyolefins are the commonly used modified polymers used as the compatibilizer in polyolefin-polyamide systems. The chemical reaction involved in the formation of block copolymers by the reaction of the amine end group on nylon and anhydride groups or carboxylic groups on modified polyolefins is shown in Scheme 1. 

Plastics used for fluidised bed powder coatings include polyethylene, p.v.c., nylon, p.v.f.2, p.e.c.t.f.e. and a variety of polyolefins and their copolymers. 

Chung and coworkers have reported on the use of stable borinale or boroxyl radicals (e.g. 114) to mediate radical polymerization." Methacrylates (MMA) and acrylates (trifluoroelhyl acrylate) have been polymerized at ambient temperature to yield polymers with relatively narrow molecular weight distributions.231233 The method has been used to prepare block copolymers and polyolefin graft copolymers.2 4 37... 

SEC-FTIR yields the average polymer structure as a function of molecular mass, but no information on the distribution of the chemical composition within a certain size fraction. SEC-FTIR is mainly used to provide information on MW, MWD, CCD, and functional groups for different applications and different materials, including polyolefins and polyolefin copolymers [703-705]. Quantitative methods have been developed [704]. Torabi et al. [705] have described a procedure for quantitative evaporative FUR detection for the evaluation of polymer composition across the SEC chromatogram, involving a post-SEC treatment, internal calibration and PLS prediction applied to the second derivative of the absorbance spectrum. 

The Zr-FI catalyst selectively forms PE even in the presence of ethylene and 1-octene, while the Hf complex affords amorphous copolymers, resulting in the catalytic generation of PE- and poly(ethylene-c6>-l-octene)-based multiblock copolymers through a reversible chain transfer reaction mediated by R2Zn. The development of an FI catalyst with extremely high ethylene selectivity as well as a reversible chain transfer nature has made it possible to produce these unique polymers. Therefore, both Ti- and Zr-FI catalysts are at the forefront of the commercial production of polyolefinic block copolymers. 

This comprises a thermoplastic elastomer based on a polyolefin and a rubber. The polyolefin is a PP homo- or copolymer having a specified weight-average molec.wt. and elongational viscosity (measured at a temperature of 170C, a rate of elongation of 0.03 1/s and at a time of 10 s). 

Multilayered materials can be readily formed using thermoforming including food packaging that may involve inclusion of layers of ethylene-vinyl alcohol copolymers, PS, polyolefins, and/or copolymers of vinylene dichloride and vinyl chloride. Microwavable food trays from (crystallized) PET are manufactured using thermoforming. 

Polyolefin poiysulfides (Thiokol) are thio analogues of polyethers which are flexible, amorphous, oil-resistant elastomers. The number of sulfur links in the repeating unit, which is called rank, is always greater than two. The solvent resistance, resistance to gaseous permeation, and flexibility of these polyolefin sulfides increase with rank. The actual strength of polymers and copolymers of olefin sulfides varies. Many of these products contain the following repeating unit ... 

---