Polymer content range

Besides the by-products from palm oil refining processes, the feasibility of using POME as the feedstock in PHA production had also been studied. Anaerobically, treated POME was used as carbon source for PHA production by Rhodobacter sphaeroides IPO 12203 and Comamonas sp. EB172 (Hassan et al. 1996, 1997b Zakaria et al. 2010a). The organic acids produced from anaerobic treatment of POME, particularly acetic and propionic acids, were successfully converted into PHA with polymer contents ranging from 59 to 67 wt% of CDW. 

FIGURE 13.11 Pressure-temperature phase diagrams for ( ) PTAN (O) PFOA, and ( ) PFDMA samples with polymer contents ranging between 3 and 4 wt%. Reproduced from Reference 28. 

PVC/NBR polymer blends can be produced as colloidal or mechanical blends, the former generally giving superior properties. Commercially available blends have PVC contents ranging from 30-55%. The blends have reduced elasticity, which gives improved extrudability, but they also exhibit superior ozone resistance, improved oil swell resistance, and tensile and tear strength this, however, is achieved at the expense of low temperature flexibility and compression set. The ozone resistance of such blends is, however, only improved if the PVC is adequately distributed and fluxed. This is harder to achieve in mechanical blends, but if it is not achieved failure due to ozone attack can occur. 

Ionic polymers other than Nation have also been included in ionic/non-ionic PEM blends. Poly(ether sulfone) (PES) has been used to strengthen SPEEK as well as sulfonated poly(ether sulfone) (SPES) with contents ranging from 20 to 60 wt%. The conductivity of the SPEEK component was relatively the same as unmodified SPEEK up to about 40 wt%. A similar effect was seen for PES/SPES blends, although the drop in MeOH permeability was more dramatic for PES/SPES from unmodified SPES than for PES/SPEEK from unmodified SPEEK. PVDF has also been used as a blending material to reinforce SPEEK. s The strength of the PEM was increased over unmodified SPEEK. Although conductivity levels decreased as a function of increasing PVDF content, the selectivity (ratio of proton conductivity to MeOH permeability) of the blended PEMs was increased over that of unmodified SPEEK and Nation. 

The large pores (ranging from 0.01 pm to 0.1 pm) are sealed by the continuous polymer film formed in the comatrix of LMM and LMC. Consequently, they show reduced water absorption, water permeability and water vapor transmission over ordinary cement mortar and concrete and this effect increases with an increase in polymer content and polymer-cement ratio (Fig. 6.15). The improved water permeability also improves the resistance to chloride ion entry and hence corrosion mitigation [87]. 

Polymers of 208 can be made with cis contents ranging from 97% (OSCI3 catalyst) to 20% (MoCl5/Me4Sn/Et20 catalyst) a somewhat narrower range (80-33%) is observed for polymers of 209. The 13C NMR spectra of the polymers of 208, containing mainly... 

Commercial aqueous dispersions of FEP are supplied with 54 to 55% by weight of hydrophobic negatively charged particles with the addition of approximately 6% by weight of a mixture of nonionic and anionic surfactants based on polymer content. The particle size range is 0.1 to 0.26 pm. Nominal pH of the dispersion is 9.5 and the viscosity at room temperature is approximately 25 cP.6... 

About three fourths of the make-up acid charged to alkylation is in the form of alkyl sulfates, and only a minor portion or about one fourth of the usual 99.5% concentration. The catalyst is, or may be, somewhat different with SARP, especially as to its water and conjunct polymer content. Without SARP the catalyst usually contains about 2.5-5.0% water. With SARP the water content should usually be in the 0.5-2.0% range. A low water content of the catalyst is believed to be desirable (26). If less drying of feed stocks in SARP were practiced, the water content of the catalyst might be as high as without SARP. 

Ethylene may be copolymerized with a range of other vinylic compounds, such as 1-butene, 1-octene and vinyl acetate (VA). These are termed comonomers and are incorporated into the growing polymer. Comonomers that contain oxygenated groupings such as vinyl acetate are often referred to as "polar comonomers." Comonomer contents range from 0 to 1 wt% for HOPE up to 40 wt% for some grades of ethylene-vinyl acetate copolymer. 

From measurements of the dielectric constant of liquid sulfur in the temperature range 134-206 °C [15] it was concluded that the molar polarization increases from 134-159 °C which was explained by the assumption of a temperature dependent equilibrium between Ss(crown) and Ss(chair) molecules, the latter possessing a permanent dipole moment owing to their low symmetry (Cs). However, the most natural rationalization of the findings is that certain components of r-sulfur like Sy and Sg—molecules of low symmetry possessing a dipole moment—contribute to the molar polarization. Since their concentration increases with temperature up to the polymerization transition it is to be expected that the molar polarization changes accordingly. Above 159 °C the molar polarization is proportional to the polymer content of the melt. 

The smallest droplets (i.e., the slowest creaming rate) are produced for the mini-emulsion in the absence of polymer, and the droplet size increases slightly with increasing polymer content (in the range of 0-1 wt %). In addition, the mini-emulsion prepared by 1 % PSt and without CA phase separated very quickly, indicating that such a product is probably not stable toward diffusional degradation. 

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