Effect of copolymer composition

The effect of copolymer composition on gas permeability is shown in Table 9. The inherent barrier in VDC copolymers can best be exploited by using films containing Htde or no plasticizers and as much VDC as possible. However, the permeabiUty of even completely amorphous copolymers, for example, 60% VDC—40% AN or 50% VDC—50% VC, is low compared to that of other polymers. The primary reason is that diffusion coefficients of molecules in VDC copolymers are very low. This factor, together with the low solubiUty of many gases in VDC copolymers and the high crystallinity, results in very low permeabiUty. PermeabiUty is affected by the kind and amounts of comonomer as well as crystallinity. A change from PVDC to 50 wt °/ VC or 40 wt % AN increases permeabiUty 10-fold, but has Httle effect on the solubiUty coefficient. 

Deschamps AA, Grijpma DW, and Feijen J. Poly(ethylene oxide)/poly(butylenes terephthalate) segmented block copolymers The effect of copolymer composition on physical properties and degradation behavior. Polymer, 2001, 42, 9335-9345. 

Zhang, L., Ma, C. and Mukerjee, S. 2005. Effect of copolymer composition on the oxygen transport properties of sulfonated poly(arylene ether sulfone) and sulfonated poly(sulfide sulfone) PEMs. Journal of the Electrochemical Society 152 A1208-A1216. 

M. Fowler, J. Barlow, and D. Paul, Effect of copolymer composition on the miscibility of blends of styrene-acrylonitrile copolymers with poly (methyl methacrylate), Polymer, 28(7) 1177-1184, June 1987. 

Hill, A.J., Winhold, S Stack, G.M., Tant, M.R. (1996) Effect of copolymer composition on free volume and gas permeability in polyethylene terephthalate) -poly(l,4 cyclohexylenedimethylene terephthalate) copolymers . Eur. Polym. J. 32(7), 843. 

If there are more than two components in a mixture (as in a blend of a homopolymer with a copolymer), binary interaction parameters can be combined into a composite % parameter to describe the overall behavior of the system. For example, Choi and Jo [11] showed how the effects of copolymer sequence distribution in blends of polyethylene oxide) with poly(styrene-co-acrylic acid) can be described by an atomistic simulation approach to estimate the binary intermolecular interaction energies which are combined into a total interaction parameter for the blend. Their paper [11] also provides a list of the many preceding publications attempting to address the effects of copolymer composition, tacticity, and copolymer sequence distribution on polymer blend miscibility. In addition to the advances in computational hardware and software which have made atomistic simulations much faster and hence more accessible, work in recent years has significantly improved the accuracy of the force fields [12] used in such simulations. 

Figure 3. Effect of copolymer composition on chain scissioning yield, G(s).

Meilchen, M. A., B. M. Hasch, and M. A. McHugh. 1991. Effect of copolymer composition on the phase behavior of mixtures of poly(ethylene-co-methyl acrylate) with propane and chlorodifluoromethane. Macromolecules 24 4874-4882. 

D. Freilich and G.B. Tanny, Hydrodynamic and microporous support pore size effects on the properties and structure of dynamically formed hydrous Zr(IV)-polyacrylate membranes, Desalination, 1978, 27, 233-251 A.J. van Reenen and R.D. Sanderson, Dynamically formed hydrous zirconium(IV) oxide-polyelectrolyte membranes, VI. Effect of copolymer composition on the stability of poly(acrylic acid - covinyl acetate) and poly(acrylic acid - covinyl alcohol) membranes, Desalination, 1989, 72, 329-338. 

Figure 7. Effect of copolymer composition in the hydrogenation ofl octene at 70 C and 172 bar. (0) RhCl(TAN2oDPPA) (a) RhCKTANisDPPA) (o ) RhCKTANjDPPA)...

Effects of Copolymer Composition. Figure 3 illustrates the effect of changes in Cg hydrophobe composition on the apparent viscosity versus... 

The effect of copolymer composition on the rate of the hydroquinone oxidation reaction has been studied using IVI-AA copolymers. Curves of the change of the oxidized hydroquinone concentration as a function of reaction time in the presence of polyampholyte-copper(II) complexes are presented in Fig. 10. An increase in the amount of basic groups in the copolymers leads to an increase in the rate of hydroquinone oxidation. Copolymers in which maleic and methacrylic acids are used as a second comonomer of IVI, exhibit lower activity than IVI-AA. 

Qiao M, Chen D, Ma X, Liu Y. Injectable biodegradable temperature-responsive PLGA PEG-PLGA copolymers Synthesis and effect of copolymer composition on the drug release from the copolymer-based hydrogels. Int J Pharm 2005 294 103 112. 

Halacheva, S.S., Adlam, D.J., Hendow, E.K., Freemont, T.J., Hoyland, J., Saunders, B.R., 2014. Injectable hiocompatible and biodegradable pH-responsive hollow particle gels containing polyfacryhc acid) the effect of copolymer composition on gel properties. Biomacromolecules 15, 1814—1827. 

BEY Beyer, C., Oellrieh, L.R., and McHugh, M.A., Effect of copolymer composition and solvent polarity on the phase behavior of mixtures of poly(ethylene-co-virtyl acetate) with cyclopentane and cyclopentene (exp. data by C. Beyer), Chem.-Ing. Techn., 71, 1306, 1999. 

Peppas and coworkers [4, 5, 42] studied the dissolution characteristics of PMMA and its copolymers. The effects of copolymer composition, nature of solvent and the dose of irradiation on the dissolution rate as well as on the thickness of the gel layer were examined. The results showed that, in most cases, the gel layer thickness increased at the beginning of the dissolution process and then decreased after reaching a maximum. 

Chen, X., Su, Y, Shen, R, and Wan, Y. 2011. Antifouling ultrafiltration membranes made from RAN-h-REG copolymers Effect of copolymer composition and REG chain length. Journal of Membrane Science 384 44—51. 

Kuo, S. W., and Chang, R C. 2001. Effect of copolymer composition on the miscibility of poly(styrene-co-acetoxystyrene) with phenolic resin. Polymer 42 9843-9848. 

Although this study did not include the effect of copolymer composition, it seems reasonable to expect that the rate of crystallization will vary inversely with the PS content in the copolymer. 

Copolymer of vinyl imidazole and vinyl trimethoxy silane films on Cu IRRAS, SEM Effect of copolymer composition on Cn corrosion protection at 360°C in air 1129... 

M. E. Rezac, T. John, P. Pfromm, Effect of copolymer composition on the solubility and dif-fusivity of water and methanol in a series of polyether amides, J. Appl. Polym. ScL, 65, 1983 (1997). 

H. Li, B. D. Freeman, S. Kalakkunnat, D. S. Kalika, Effect of copolymer composition, temperature, and carbon dioxide fugacity on pure- and mixed-gas permeability in poly(ethylene glycol)-based materials Free volume interpretation, J. Membr. ScL, 291, 131-139 (2007). 

FIGURE 57.5. Effect of copolymer composition on the dissolution rates of poly(4-hydroxystyrene -co-styrene) in 0.26N TMAH at room temperature [36]. 

K. Sanechika, T. Yamamoto and A. Yamamoto. Preparation of copolymers composed of 2,5-thienylene and 2,4-thienylene units. Effect of copolymer composition on electronic spectrum, electric conductivity and chemical properties. J. Polym. Sci., Polym. Lett. Ed. 20(7), 365-371 (1982). 

Park, T. G. 1995. Degradation of poly(lactic-co-glycolic acid) microspheres - effect of copolymer composition. Biomaterials, 16, 1123—1130. 

Manoharan, C., Singh, J., 2009. Evaluation of polyanhydride microspheres for basal insulin deUvery effect of copolymer composition and zinc salt on encapsulation, in vitro release, stability, in vivo absorption and bioactivity in diabetic rats. Journal of Pharmaceutical Sciences 98, 4237—4250. 

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