Extractable poly amount

Substantial amounts of polymalatase have been isolated from plasmodial extracts. This may refer to stored enzyme before secretion, because /3-poly(L-malate) is not degraded in plasmodia [24]. Several other fungi were found to secrete /3-poly(L-malate) degrading activities to L-malic acid (Ratberger, Molitoris and Holler, unpublished results). These enzymes have not yet been purified and characterized. 

A completely automated system with reinjection/sample collection and solvent recovery allows the separation of up to 10 g of extract a day. The Cjq is obtained in very high purity and the recovery is nearly 100%. A simple benchtop method for the enrichment of preparative amounts of Cjq, C7Q and higher fullerenes (up to Cjqq) from a crude fullerene mixture is based on a single elution through a column of poly(dibromostyrene)-divinylbenzene using chlorobenzene as mobile phase [208]. 

Polv(ether) Synthesis. The poly(ethers) were made by a two-phase reaction with dibromoalkanes. In a typical reaction, 0.75 g (2.4 mmol) of (II, R=H)) was mixed with 70 ml of 2N NaOH in a 3-necked round-bottom flask equipped with a mechanical stirrer. To this was added an equimolar amount of 1,9-dibromononane in 20 mL nitrobenzene and approximately 10 mg of tetrabutylammonium iodide and the mixture was stirred overnight at 50°C. The resulting solid mass was washed with methanol and then with 2N NaOH. After washing with 0.1 N HC1, the product was Soxhlet-extracted with methanol and dried to yield 0.68g (64.7%) of a light green powder which melted to an anisotropic liquid at 290°C. The other poly(ethers) were prepared in the same manner, using spacer lengths of 7, 9,11, 7/9 mixture, and 9/11 mixture. The yields and IR spectra of the poly(ethers) is shown in Table I. 

Some grafting between polystyrene and polyethylene may occur, but we think not. Substantial amounts of polystyrene (but not all) have been extracted from the blend samples by soaking the specimens in refluxing THF for several days. We suspect that if grafting does occur, it is not a significant contributor to polystyrene mass uptake. All the polystyrene could be extracted from a 50 wt % polystyrene/poly(4-methyl-l-pentene) (PMP) blend that was prepared by essentially the same procedure. The backbone of PMP (with two tertiary C —H bonds per repeat unit) is likely more susceptible to radical grafting than HDPE. 

The amount of radicals in carbon black filled rubbers decreases significantly upon extraction of free rubber with the aid of a solvent containing a free radical scavenger. The extraction nevertheless causes a substantial increase in the fraction of the T2 relaxation component with the decay time of about 0.02-0.03 ms [62], This increase is apparently caused by an increase in the total rubber-carbon black interfacial area per volume unit of the rubber due to the removal of free rubber. The T2 relaxation component with a short decay time is also observed in poly(dimethyl siloxane) (PDMS) filled with fumed silicas [88], whose particles contain a minor amount of paramagnetic impurities. Apparently, free radicals hardly influence the interpretation of NMR data obtained for carbon-black rubbers in any drastic way [62, 79]. 

Low Voltage Mass Spectrometry. The nominal parent mass numbers of the various components in the low molecular weight extractable fractions obtained from polyoctenamer and poly-1,5-octadienamer are listed in Table I. Quantitative estimation of the relative amounts of individual components were not carried out owing to experimental difficulties. The large variation in the volatilities of the various oligomers limits this procedure to the determination of molecular weights of the oligomers. 

Unseparated Catalyst. Unaged Catalysts. Our previous work (13) with the triisobutylaluminum-titanium tetrachloride catalysts preformed at 20° C. had shown that the optimum Al/Ti ratio for c is-1,4 poly isoprene formation is about 0.9 to 0.1. The yields of solid polymer fell off rapidly on either side of this ratio. Lower ratios led to mixed leathery-rubbery products of high gel, whereas higher ratios (above 1.3) produced increasing amounts of low molecular weight oily materials, so-called extractables. 

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