Polypropylene conversion

Rank the following polypropylene conversion processes in terms of their relative sensitivity to particulate contamination, film casting, injection molding or fiber spinning. 

Deep fluonnation using the La-Mar technique was carried out on polymers such as polyethylene and polypropylene [M], on polyethers [19, 20, 21], and on polyesters subsequently treated with sulfur Cetrafluoride [22] Deep fluorinations carried out under conditions producing limited fragmentation produced oligomeric perlluoropolyethers from powdered polyethylene oxide [23] Deep fluorinations earned out in the limited presence of molecular oxygen result in the conversion of... 

This paper summarises an initial feasibility on reeyling scrap automotive plasties and eomposites using a eatalytie conversion process. The eharaeterisationofhydroearbon products is presented for sheet moulding compound (SMC), auto shredder residue (ASR) and reinforeed polypropylene (R-PP) materials and mixtures of body panels. Gas chromatography and scanning electron microscopy is used for the material characterisation. 26 refs. 

Figure 30 The hydroboration strategy of chain end olefinic unsaturation in polypropylene with 9-BBN for further conversion into block copolymers via polymer radicals. (Adapted from refs. 66 and 67.)...

Our library synthesis was carried out with a set of 27 tube-shaped solid phase synthesis support, called MicroTubes. These supports are prepared by radiation grafting of polystyrene ( — 350 pmol) onto polypropylene tubes, chemically functionalizing the polystyrene with aminomethyl groups to afford about 55 imol of amine per tube, inserting a reusable Rf ID tag into each tube, and heat-sealing the tube ends to prevent loss of the tag. The chemical conversion of all 36 aminomethyl tubes was carried out simultaneously using standard procedures with rink amide linker, each with —46 pmol of available amine per tube.1 2... 

During processing polypropylene melts under the action of transverse strain there occur strain-chemical conversions which can result in both decrease and increase in their molecular masses the mechanical effect on the rapidity and level of the occurring processes is considerably more prominent than the mere contribution of thermal and thermal-oxidative breakdown. These data necessitate studying the process of polymer destruction. For this purpose it would be most effective to apply the criterion of assessment of the intensity with which destructive processes happen in polymer melts. 

This author and coworkers at Beckman Coulter first described the use of a low form 96-well plastic microplate for automated micro-ELISA immunoassays (Matson et al., 2001). The polypropylene plate was first modified by a radiofrequency plasma amination process (Matson et al., 1995) followed by conversion to an acyl fluoride surface chemistry for rapid covalent attachment of biomolecules. Proteins (1 to 2 mg/mL) were prepared in 50 mM carbonate buffer, pH 9, containing 4% sodium sulfate (to improve spot uniformity) and printed using a conventional arrayer system. Approximately 200-pL droplets of monoclonal antibodies (anti-cytokine) were deposited into the bottom of the microwells using a Cartesian PS7200 system equipped... 

Earlier transition metals, as zirconium and hafnium, are still more active in hydrogenolysis, which allows zirconium hydrides to be used in depolymerization reactions (hydrogenolysis of polyethylene and polypropylene) [89], In this case, the zirconium hydride was supported on silica-alumina. Aluminum hydrides close to [(=SiO)3ZrH] sites would increase their electrophilicity and, thus, their catalytic activity. A catalyst prepared in this way was able to convert low-density polyethylene (MW 125000) into saturated oligomers (after 5h) or lower alkanes at 150°C (100% conversion). It was also able to cleave commercial isotactic polypropylene (MW 250000) under hydrogen at about 190 °C (40% of the starting polypropylene was converted into lower alkanes after 15 h of reaction). 

The resolution of racemic FTC butyrate (34) was required for the synthesis of the antiviral drug emtricitabine (Emtriva) (Scheme 7.15) a nucleoside reverse transcriptase inhibitor targeted for treatment of human immunodeficiency virus (HIV) and hepatitis infections [35]. The racemic FTC butyrate ester (34) was treated with immobilized cholesterol esterase, which cleaved the required isomer to the corresponding alcohol (-) 35 with 91% and 52% conversion [36]. The product was isolated as the hydrochloride salt to give 31% yield (98% ) from the 8 kg demonstration. The esterase was immobilized by precipitation onto an accurel polypropylene support using acetone followed by cross linking with glutaralde-... 

Tphe major objective of this work was to understand better the effect - of heavy metals in autoxidation reactions in view of the importance of trace metals in oils, fats, rubber, plastics, and other materials. Because of our interest in the stability of polyolefins such as polyethylene and polypropylene the major model substance used was 2,6,10,14-tetramethyl-pentadecane. With its four tertiary C—H bonds it is a suitable model for either polypropylene or branched polyethylene. Hexadec-l-ene was also used since its mono-olefinic character could be typical of some residual unsaturation in polyethylene. N-alkylamides served as model substances for polyamides, and a few experiments were also carried out with methyl linoleate. While studying the causes of initiation of the autoxidation of these substances we observed that certain compounds were catalysts at low concentrations but became inhibitors at higher concentrations. The phenomenon was called catalyst-inhibitor conversion. ... 

Spent filter materials Plating and chemical conversion Cotton, activated carbon, paper, ceramic, diatomaceous earth, polypropylene and other plastic filter materials, and the same contaminants listed above under "filter sludges."... 

Figure 7. Time-conversion plot for 1,5-pentanediol initiated preparation of polypropylene ether) diol in pentane (propylene oxide/pentane wt ratio = 3) with Zns[Co(CN)6]2 glyme ...

The reaction of living polypropylene with H2 has been examined by Doi, Ueki and Keii102). Figure 18 shows the results of the polymerization of propylene with the V(acac)3/A1(C2H5)2C1 catalyst at —78 °C in the absence or presence of H2. The yield of polymer as a function of time, i.e. the polymerization rate, was scarcely affected by the presence of H2. Conversely, in the presence of H2, Mn increased toward... 

It should also be noted that the viscometric technique can detect the presence of star-shaped aggregates, having the ionic active centers. The addition of ethylene oxide to hydrocarbon solutions of poly(isoprenyl)lithium leads to a nearly two-fold increase in viscosity144). Conversely, this results in an approximately twenty-fold decrease in solution viscosity, after termination by the addition of trimethylchloro-silane. This change in solution viscosity is reflected in the gelation which occurs when difunctional chains are converted to the ionic alkoxy active centers 140,145,146). Branched structures have also been detected 147> by viscometry for the thiolate-lithium active center of polypropylene sulfide) in tetrahydrofuran. 

Most processes for separating individual species from petroleum involve use of refined engineering methods, with distillation and selective adsorption the most important. Once separated, however, most materials then undergo chemical conversion into more desirable products. Alkylation involving propene and butenes yields C6 to C8 hydrocarbons for high-octane gasoline. Propylene becomes polypropylene, propylamine, or propylene glycol and ethers. 

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