Polyolefin Sulfides

Radhakrishnan and Rao [1] have studied the kinetics and mechanism of the degradation of thiol terminated polysulfide polymers HS(RSS) RSH, R-CH -CH OCH -OCH -CH - which have been cured with ammonium dichromate using pyrolysis-gas chromatography (Py-GC) and isothermal and dynamic thermogravimetric analysis (TGA). 

Isothermal thermogravimetric measurements were made at 268,280,290 and 299 °C. The isothermal rate of volatilisation, da/dt, was calculated numerically as a function of conversion. A maximum in the rate of volatilisation is observed at 28 % conversion, which compares favourably with the 26% predicted by Simha and co-workers [3] and by Boyd [4] for random initiated degradation. Hence, a kinetic model based on random degradation was considered. 

The cured and the liquid polymers degrade essentially by the same mechanism (see Equation 6.1). The kinetic analysis of the isothermal and dynamic thermogravimetric data of the liquid polysulfide polymer cured with ammonium dichromate is explained by a kinetic model based on random initiation, followed by rapid termination by disproportionation. The average overall activation energy obtained by different methods for the decomposition is 145.3 kj/mole  

Py-GC at 420 °C and 470 °C of liquid cured [LP2(I)] and ammonium dichromate cured [LP2(II)] polysulfide polymers gave pyrograms in which the predominant components were  

Peak 2 1,2-mercaptomethyl oxirane Peak 3 l,3-dioxa-6-thiocane 

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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 ... 

Plastics Additives. Many claims have been made for the use of nickel chemicals as additives to various resin systems. By far the most important appHcation is as uv-quenchers in polyolefins (173,174). Among the useful nickel complexes in these systems are dibutyldithiocarbamate nickel [13927-77-0], nickel thiobisphenolates, and nickel amide complexes of bisphenol sulfides (175). The nickel complex of... 

Fig. 11. Effect of polyolefin primers on bond strength of ethyl cyanoacrylate to plastics. All assemblies tested in accordance with ASTM D 4501 (block shear method). ETFE = ethylene tetrafluoroethylene copolymer LDPE = low-density polyethylene PFA = polyper-fluoroalkoxycthylene PBT = polybutylene terephthalate, PMP = polymethylpentene PPS = polyphenylene sulfide PP = polypropylene PS = polystyrene PTFE = polytetrafluoroethylene PU = polyurethane. From ref. [73].

Polycarbonates Poly(ether ether ketone) Poly(ether ketone) Poly(ether sulfones) Poly(phenylene sulfide) Polyethylene Acetal Polyolefins... 

MC MDI MEKP MF MMA MPEG MPF NBR NDI NR OPET OPP OSA PA PAEK PAI PAN PB PBAN PBI PBN PBS PBT PC PCD PCT PCTFE PE PEC PEG PEI PEK PEN PES PET PF PFA PI PIBI PMDI PMMA PMP PO PP PPA PPC PPO PPS PPSU Methyl cellulose Methylene diphenylene diisocyanate Methyl ethyl ketone peroxide Melamine formaldehyde Methyl methacrylate Polyethylene glycol monomethyl ether Melamine-phenol-formaldehyde Nitrile butyl rubber Naphthalene diisocyanate Natural rubber Oriented polyethylene terephthalate Oriented polypropylene Olefin-modified styrene-acrylonitrile Polyamide Poly(aryl ether-ketone) Poly(amide-imide) Polyacrylonitrile Polybutylene Poly(butadiene-acrylonitrile) Polybenzimidazole Polybutylene naphthalate Poly(butadiene-styrene) Poly(butylene terephthalate) Polycarbonate Polycarbodiimide Poly(cyclohexylene-dimethylene terephthalate) Polychlorotrifluoroethylene Polyethylene Chlorinated polyethylene Poly(ethylene glycol) Poly(ether-imide) Poly(ether-ketone) Polyethylene naphthalate Polyether sulfone Polyethylene terephthalate Phenol-formaldehyde copolymer Perfluoroalkoxy resin Polyimide Poly(isobutylene), Butyl rubber Polymeric methylene diphenylene diisocyanate Poly(methyl methacrylate) Poly(methylpentene) Polyolefins Polypropylene Polyphthalamide Chlorinated polypropylene Poly(phenylene oxide) Poly(phenylene sulfide) Poly(phenylene sulfone)... 

Zinc sulfide 170 Polyolefin, LLDPE, HDPE, ionomer... 

Very few CPs are produced in bulk quantities. Polyphenylene sulfide, a member of the third generation of polymers, was produced in bulk quantities many years before CPs were established and its dopability was elucidated. Polyethylenedioxythiophene is commercially available as a water-based colloidal dispersion (Baytron P water dispersion), and presumably as dispersible powders. The powders with a conductivity of 5-10 S/cm can be dispersed in thermoplastic polymers and in organic solvents such as xylene. Polyaniline doped with dodecylbenzene sulfonic acid and complexed with zinc dodecylbenzene sulfonate is commercially available as a powder, which can be dispersed in polyolefins. The same polymer doped with p-toluenesulfonic acid is also available as a dispersible powder, Ormecon, and in a predispersed form for solution processing in polar and nonpolar media. Based on Ormecon PANi, there are many commercial products marketed for many different applications. 

A patent (6) assigned to the Societe Nationale des Petroles d Aqui-taine covers the use of, for example, a polymer made by the interaction of epichlorohydrin, hydrogen sulfide, and alkali or alkaline earth polysulfide in aqueous solution. This polymer, HS—[CH2—CHOH—CH2— S]nH where n = 4-24, is mixed with elemental sulfur, a polyolefin (e.g. polybutene), and an olefin (e.g. styrene). This type of mixture, after heating at 140-160 °C, has been used for traffic striping and is said to be serviceable without flaking after 1 years use, despite heavy traffic. 

Beilstein Handbook Reference) Antage Crystal Antioxidant AO Antioxidant TMB 6 Bis(3-tert-butyl-4-hydroxy-6-methylphenyl) sulfide BRN 1147776 CCRIS 4917 Disperse MB-61 EINECS 202-525-2 HSDB 5304 Nocrac 300 Nonflex BPS NSC 35388 Rutenol Santonox Santonox BM Santonox R Santowhite crystals Santox Sumilizer WX Sumilizer WX-R Thioalkofen BM 4 Thioalkofen BMCH Thioalkofen MBCH Thioalko-phene BM-4 Ultranox 236 USAF B-15 Yoshinox S Yoshinox SR, Antioxidant for use in adhesives, rubber articles for repeated use, polymers include polyolefins, PVC, xrylic ethyl cellulose antioxidant for lubricants, cutting oils, water-sol. oils, hydraulic oils. Solid mp = 161-164° insoluble in H2O. GE Silicones. 

Nonolefinic thermoplastic polymers that in principle may be blended with polyolefins include polyamides (nylons) such as polyamide 6, polyamide 66, polyphenylene sulfide (PPS), polyphenylene ether (PPF), and polyphenylene oxide (PPO) polyesters such as polyethylene terephthalate (PET), polybutylene terephtha-late (PBT), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polycarbonates, polyethers, and polyurethanes vinyl polymers such as polystyrene (PS), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA), and ethylene... 

The most recent development in separation is the development of high temperature interaction chromatography, which extends the composition distribution analysis to polyolefin copolymers of very low crystallinity, which is not possible to analyze by crystallization techniques. The analysis of complex polymers with different composition can be analyzed in a short time by solvent gradient interaction chromatography, SGIC, on an atomically flat surface like carbon or molybdenum sulfide packing. The addition of a second separation step by GPC (SGIC2D) provides the capability to obtain full composition-molar mass dependence. 

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