Polymer conversion ratio

The overall polymer conversion ratio is given by kg times the total surface area. The temperature dependence of polymer deposition for various monomers (of difierent molecular weights) under difierent discharge conditions is best expressed in terms of the normalized deposition rate kg rather than deposition rate ki or k2 because the actual deposition rate observed under a set of conditions is dependent on the mass flow rate (see Chapter 8). 

Total mass of monomer introduced into the system Total mass of deposition W2 Total mass exits from the reactor W3 Monomer-polymer conversion ratio ... 

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

This transfer reaction with polymer, which reactivates a polymer molecule, is, at least partially, responsible for the production of branched polymeric molecules1 its importance should increase with the polymer-monomer ratio and therefore with an increasing degree of conversion (38,39,40). The site of attack may be located either in the substituent of... 

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). 

Another polyester that has reached longterm commercialization is now produced in limited volume as Kodel 200 by Tennessee Eastman Co. and is considered to be 1-4 cyclohexylene dimethylene terephthalate. The glycol that is used instead of ethylene glycol in this process exists in two isomeric forms, one melting at 43°C and the other at 67°C. This makes possible their separation by crystallization, to secure the desired ratio of the two forms for conversion to the polymer. This ratio determines the melting point of the polymer, a most important property for a material that is to be melt-spun. The polymer from the 100 percent cis form melts at 275°C, and that from the 100 percent trans form at 318°C. Indications are that the commercial product is about 30/70 cis-trans. 

The value of pg largely reflects the pressure of the non-polymer-forming gases in the plasma (by-product of the plasma polymerization) when the conversion ratio of monomer to polymer is high. Therefore, the control of pg is important with respect to the ionization characteristics of the product gas, which is important for... 

The amount of SO2 vs. chlorine in the reaction mixture affects the resultant ratios of chlorosulfonation vs. chlorination of the polymer. These ratios and the amounts of conversion vary with the temperature. " ... 

FIGURE 42.2 UV-induced cross-linking in diacetylene LB films. Percent polymer conversion plot is based upon the 288/ Ag ratio (intensity ratio between a daughter ion representative of the analyte molecule and the silver-related signal) versus time of UV exposure. Figure from Reference [28]. 

The conversion of cyclic monomers to polymer chains requires the use of initiator/ catalyst. Many initiation systems have been reported in literature during the past decades. Among them, tin (II) 2-ethyl hexanoate or stannous octoate (SnOct2) is the most commonly used catalyst because it provides high reaction rate, high conversion ratio, and high molar mass even under relatively mUd conditions (Schwach et al.,... 

Fig. 8. Raman spectra for photopolymerization of 2-hydroxyethyl methacrylate initiated with 2 mmolal dimethoxyphenylacetophenone at 50°C and light intensity of 75 mW/cm Raman spectra of the monomer and its polymer (left) and degree of monomer conversion based on monitoring the C=C bond depletion at 1640 cm (in this system, the internal reference band at 605 cm is constant throughout the reaction and cancels out in the conversion ratio) (right).

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