Monomers and copolymers

Einsla, B. R., Hong, Y. T., Kim, Y. S., Wang, F., Gunduz, N. and McGrath, J. E. 2004. Sulfonated naphthalene dianhydride based polyimide copolymers for proton-exchange-membrane fuel cells. 1. Monomer and copolymer synthesis. Journal of Polymer Science Part A Polymer Chemistry 42 862-874. 

The first system is based on a poly (norbornene)-supported Co salen and the second system is based on a poly(styrene) backbone. For the poly (norbornene) system, a homopolymers and several different copolymers were prepared (44), with varying fractions of Co salen side-chains and spacer side-chains (Figure 3, copolymer la-c and homopolymer Id). For the poly (styrene) system, both homopolymers of salen-containing monomers and copolymers with styrene (45,46) were prepared (Figure 3, copolymer 2a-c and homopolymer 2d). 

Another widely used form expresses the instantaneous monomer and copolymer concentrations in terms of mole fractions. For monomer 1 this would be defined as ... 

The closed system techniques currently used in styrene monomer and copolymer resin production limit worker exposures to a time-weighted average (TWA) exposure of generally <10 ppm. However, in open... 

All of the product vinyl acetate is consumed in the production of homopolymer (one monomer) and copolymer products, among them poly(vinyl acetate) latices and resins, poly(vinyl alcohol) by postpolymerization hydrolytic removal of the acetate, and copolymers with vinyl chloride and ethylene. 

Problem 7.5 A monomer pair with rj = 0.2 and T2 = 5.0 is copolymerized beginning with a molar monomer ratio [Mi]/[M2] = 60/40. Assuming that the copolymer composition within a 10 mol% conversion interval is constant, calculate instantaneous monomer and copolymer compositions and cumulative average copolymer compositions at 10 mol% conversion intervals up to 100% total conversion. Show the results graphically as change in composition of the copolymer and the monomer mixture during copolymerization. 

With r = 0.52 and T2 = 0.46, calculate from Eq. (7.24) the changes in instantaneous monomer and copolymer compositions as a function of conversion and compare the results graphically with the above experimental data. Also calculate the cumulative average copolymer composition at different conversions. 

A compilation of the lipase-catalyzed lactone, cyclic ester related monomers and copolymers, the enzymes used, and the corresponding citation(s) are given in Table 4.4. 

The analysis of copolymer composition in Section 4.6.4.1 has been carried out using the terminal model which assumes that radical reactivity is solely determined by the terminal unit on the free-radical chain. The terminal model has been successfully applied to represent the monomer and copolymer compositions for a wide variety of systems, mostly studied at ambient pressure. This model is, however, not capable of describing both copolymer composition and copolymerization kinetics with a single set of reactivity ratios [63]. 

Frequently, the desired bulk properties cannot be achieved by using only one monomer and copolymers of glassy and rubbery polymers of different compositions are used. This is illustrated in general by the following list of some industrially important polymer families with their end-use areas ... 

Recently a similar monomer and copolymer to those of the above short side chain type were reported [35-38]. The monomer has four CF2 units (Fig. 15). Its copolymer with TFE exhibited a similar softening point to that... 

It was found that SE values [in both X-band (8.2-12.4 GHz) and Ku-band (12.4-18.0 GHz)] of pure PANI (GPIOOA) and substituted PANIs followed electrical conductivity trend (Figure 9.32a). It has also been observed that with the decreasing bulkiness of substituent, both SEj and SE values (say at 18.0 GHz) increases (Figure 9.32b), which can be attributed to the increase in electrical conductivity. Therefore, by carefully controlling the nature of co-monomer and copolymer composition, SE.j, and processability can be tailored. 

Scheme 1 Chtamcal structures and abbreviatirais of monomers and copolymer systems NIPA N-isopropylaciylamide, DMAA NAf-dimethylacrylamide, MEA 2-methoxyethyl acrylate, ND polymer polymer based on NIPA and DMAA, MD polymer polymer based on MEA and DMMA, As N,N-dimethyl(aciylamidopropyl) ammonium propane sulfraiate...

Equation (10.27) can be used to calculate the copolymer composition given the monomer compositions. The inverse problem of finding the monomer composition for a desired polymer composition would require rearranging Equation (10.26) and expressing A in terms of Fj. It appears that the expression would be quadratic in/i. Does this mean that there would be multiple or two roots to a desired polymer composition for some set of reactivity ratios The monomer and copolymer composition for the system of diethyl fumarate and acrylonitrile is shown in Figure 10.3. 

Let the monomer 1 be methacrylonitrile (MAN) and monomer 2 be styrene (STY). It can be seen from Table 10.1 that the reactivity ratios 2 and r2i are equal to each other and are 0.25. The monomer and copolymer composition curve is shown in Figure 10.4. 

CALB was employed as the catalyst for the ring-opening copolymerisation of (O-PDL with p-dioxanone (DO) under mild reaction conditions (<80 C, atmospheric pressure). Poly(co-pentadecalactone-co-p-dioxanone) (poly(PDL-co-DO)) with high MW (MW >30,000 Da) and a wide range of comonomer content was synthesised using various PDL/DO feed ratios. The copolymers were typically isolated in 50-90 wt% yields as the monomer conversion was limited by the equilibrium between the monomers and copolymers [136]. 

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