Polymer conversion

Many units have waste heat recovery systems that generate low pressure steam from reaction heat. Such steam is often employed to drive adsorption refrigeration units to cool the reactor feed stream and to increase polymer conversion per pass, an energy-saving process that reduces the demand for electrical power. 

Holmes-Wallcer, W.A, Polymer Conversion, Applied Science Publishers, 1975. 

Polymerization/lsomerization. The polymerization of 5-methyl-1,4-hexadiene (>99% pure) was carried out in n-pentane with a (5-TiCl3/Et2AlCl catalyst at 0°C according to the procedure described previously (14). To assess monomer disappearance and identify isomerization products, samples were withdrawn at specified intervals from the reaction mixture for GLC analysis (14). The final polymer conversion was determined by precipitation in excess methanol. 

From following table, we can see that even for a degree of polymerisation of 100 (which, in fact, corresponds to low Molecular weight polymers), conversion has to be as high as 99 per cent. 

Pultrusion is a steady-state process in which the fiber-resin mass changes its properties as it moves from the entrance to the exit of the die. In order to track the temperature, polymer conversion, and other properties of the fiber-resin mass as it moves along the die, it is useful to define a representative volume element (RVE) that rides along the fiber at the line speed of the pultrusion process. An RVE is defined such that it will contain both the solid phase (i.e., fibers and resin), irrespective of its location in the composite. In real-life pultrusion, a thermocouple wire that passes through the pultrusion die tracks the temperature of an RVE in the composite. 

This review indicates that good solvent conditions (in terms of either x or 0) result in a positive value for AGR. This is what would be expected from a model that assumes that the first encounter between particles with adsorbed layers is dominated by the polymers. Conversely, in a poor solvent AGR is negative and amounts to a contribution to the attraction between the core particles as far as flocculation is concerned. Under these conditions the polymer itself is at the threshold of phase separation. Van der Waals attraction between the core particles further promotes aggregation, but it is possible that coagulation could be induced in a poor solvent even if the medium decreases the effective Hamaker constant to zero. 

Poly(AcAm/AA) Temp. °C mole ratio Reaction time hours Taurine charge mole % based on polymer % Conversion based on taurine1... 

In a series of runs carried out according to Procedure A using a ratio water/rubber + monomer = 2.4 in the presence of 0.38% of Bz202 the behavior of the monomer-polymer conversion vs, time at 70°C (Figure 1) shows evidences of autoacceleration, which characterizes the homopolymerization of vinyl chloride (3, 5). 

Pan, L., Woodlock, B., Wang, X., Lam, K.C., Rheingold, A. L., Novel silver -Organic Coordination Polymers conversion of extended structures in the solid state as driven by argentophilic interactions. Chem. Commun. 2001, 1762-1763. 

Variables Affecting Conversion to Polystyrene. The conversion of styrene in dioxan (30% w/w) reaches a maximum at approximately 0.1M H2SO4 (Table 1). Beyond this acidity, the yield of hompolymer is not significantly increased under the radiation conditions used. At acid concentrations in excess of 0.7M there is a fall off in yield of polystyrene which may be attributed to the lower solubility of polystyrene at higher acid levels so that continued polymerisation is hampered by increasing immiscibility. The data in the same table show that the effect of water on the homopolymerisation is different from that of acid. The polymer conversion is also favored at the lower monomer concentrations (Table II) and is enhanced by the presence of acid at each monomer concentration studied. The conversion is also directly proportional to the total radiation dose (Table III) and inversely proportional to the dose rate (Table IV). The addition of acid in each case enhanced the resulting yields of homopolymer. ... 

Block Polymer Made with Active and Inactive Polypropylene. Inactive polypropylene powder in hexane suspension was treated with (CH3CH2)2A1C1, TiCl3, water, N,N-dimethylaminoethyl methacrylate, and benzoyl peroxide under the same conditions used to prepare AFR polymer. Just as for the polypropylene-methylvinylpyridine-acrylonitrile system, the inactive polypropylene did not show evidence of incorporation of the free radical polymer (Table XIV). When inactive polypropylene was used, the —COOR absorbance of the polymer was only about 10-30% as great as the —COOR absorbance with active polypropylene. With active polymer conversion to block formation increased as the... 

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