Poly-blends

Sulfonation has been used to change some characteristics of blends. Poly(2,6-diphenyl-l,4-phenylene oxide) and polystyrene are immiscible. However, when the polymers were functionalized by sulfonation, even though they remained immiscible when blended, the functionalization increased interfacial interactions and resulted in improved properties (65). In the case of DMPPO and poly(ethyl acrylate) the originally immiscible blends showed increased miscibility with sulfonation (66). 

Wang and Chen [41] studied the compatibility problems of incompatible NBR-PVC blends. Poly(vinyl-idene chloride-covinyl chloride) is reported to act as an efficient interfacial agent. Blends of PVC, NBR, and the copolymer were prepared by the solution casting technique using THE as a solvent. Improvement in mechanical properties can be achieved in NBR-PVC blend by the addition of different types of rubbers [42]. Different rubbers include NR, styrene butadiene (SBR) and butadiene (BR). Replacement of a few percent of NBR by other rubbers will improve the mechanical properties and at the same time reduce the cost of the blend. 

Poly- anion Blend No. Composition of Polyanion Blend Composition of Polycation Blend Poly- cation Blend No. 

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. 

Poly(vinyl chloride) was also masticated with neoprene in an inert atmosphere at 145° C for 30 min (60), giving an easily flowing powder of low bulk density. Goto and coworkers (61) blended poly(vinyl chloride), poly(methyl methacrylate) and polystyrene in an open roll after investigating the degradation condition for each component to find the optimum combination of the component. 

Figure 9.7-1 Experimental cloud-point curve of the polymer blend Poly(methyl methacrylate)/Poly(styrene-co-acrylonitrile (28%AN)) as a function of pressure.

Since there had not been any measurements of thermal diffusion and Soret coefficients in polymer blends, the first task was the investigation of the Soret effect in the model polymer blend poly(dimethyl siloxane) (PDMS) and poly(ethyl-methyl siloxane) (PEMS). This polymer system has been chosen because of its conveniently located lower miscibility gap with a critical temperature that can easily be adjusted within the experimentally interesting range between room temperature and 100 °C by a suitable choice of the molar masses [81, 82], Furthermore, extensive characterization work has already been done for PDMS/PEMS blends, including the determination of activation energies and Flory-Huggins interaction parameters [7, 8, 83, 84],... 

Y.F. Xu, R.Y.M. Huang, Pervaporation separation of ethanol-water mixtures using ionically crosslinked blended poly(acrylic acid) (PAA)-nylon 6 membranes, J. Appl. Polym. Sci. 36 (1988) 1121— 1128. 

In order to control the pore texture in carbon materials, blending of two kinds of carbon precursors, the one giving a relatively high carbonization yield and the other having a very low yield, was proposed and called polymer blend method [112], This idea gave certain success to prepare macroporous carbons from poly(urethane-imide) films prepared by blending poly(amide acid) and phenol-terminated polyurethane prepolymers [113]. By coupling this polymer blend method with... 

Miles IS, ZurekA (1988) Preparation, structure, and properties of two-phase co-continuous polymer blends. Poly Eng Sci 28 796... 

Homopolymer (A)/random copolymer (B) blends, poly(1)/poly(2-ran-3). Phase behavior may be discussed in terms of the interaction parameter XAB which is given in the mean-field approximation by [2, 3]... 

Polyesters also are used in various polymer blends such as polycarbonate/poly(butylene terephthalate), poly(butylene terephthalate/acrylonitrile-styrene-acrylic) blends, poly(vinyl chloride)/poly(ethylene terephthalate), etc. Pyrolysis results on poly(vinyl chloride)/ poly(ethylene terephthalate) have been reported [64] showing that the two components influence each other, chloroesters of terephthaiic and benzoic acids being found in the pyrolysate. 

Kim, D.W., Park, J.K., and Rhee. H.W. 1996. Conductivity and thermal studies of solid polymer electrolytes prepared by blending poly(ethylene oxide), poly(oligo[oxyethylene] oxysebacoyl) and lithium perchlorate. Solid State Ionics 83, 49-56. 

Scalco, Huseby, and Blyler (8), Zosel (9), and Bergen and Morris (10). Prest and Porter (23) applied the same principle to homopolymer blends [poly (2,6-dimethylphenylene oxide)-polystyrene]. Recently some papers were published on triblock copolymers of styrene-butadiene-styrene and on their blends with polybutadiene (24, 25). Triblock copolymers can be considered heterophase material as the different constituent blocks are thermodynamically incompatible with each other, and, consequently, polystyrene domains are enclosed in polybutadiene (continuous matrix). The findings indicate that these systems are in general thermorheologically complex, so that the shift factor ar depends not only on temperature but also on time. These conclusions have been extrapolated to other two-phase systems. 

Polyiphenylene Sulfide) Blends Poly(phenylene sulfide), PPS, is an expensive, high-performance, but brittle specialty resin. Blending can offer a good alternative both in... 

Bromine is an effective flame retardant and bromine-containing blends poly(di-bromo-propyl acrylate) with PMMA and PMA) have been studied with this in mind [Grassie et al., 1987 Diab, 1986]. Though the degradation products are those expected from the individual components it has recently been found that high temperature pyrolysis of blends (600°C) containing bromine flame retardants can generate detectable (ppm) amounts of para-dioxins [Luijk and Go vers, 1992]. 

Through the synthesis of poly(urethane-imide) films and their carbonization, carbon films were obtained whose macropore structure could be controlled by changing the molecular structure of polyurethane prepolymer [164-166]. Poly(urethane-imide) films were prepared by blending poly(amide acid), which was synthesized from pyromellitic dianhydride (PMDA) and 4,4 -oxydianiline (ODA), and phenol-terminated polyurethane pjrejwlymers, which were synthesized through the reaction of polyester polyol with either hexamethylene diisocyanate (HDI), tolylene-2,4-diisocyanate (TDI) or 4,4 -diphenyknethane-diisocyanate (MDI). The reaction schemes of two components, poly(imide) (PI) and poly(urethane) (PU), are shown in Fig. 46a). 

The block or graft copolymer used as a compatibilizing agent must have the ability to separate into their respective phase and not be miscible as a whole molecule in one phase. The best choice of block or graft copolymers would be to choose polymers identical to the blended polymers, e.g., poly(A-fo-B) or poly(A-g-B) copolymers for blending poly(A) and poly(B). Another alternative is to use poly(C-fo-D) or... 

Melt blending poly(phenylene ether), poly(styrene) and curable epoxy resins yields materials that are suitable for use as adhesives in electronics applications. In particular, the composition is useful in laminating films for electronic applications. 

Lyocell tibers have been explored in blends. Chang et al. [141] prepared Lyocell based blends. Poly(vinyl alcohol) (PVA), poly(vinyl alcohol-co-ethylene) (EVOH), and poly(acrylic acid-co-maleic acid) (PAM) were used as fillers in blends with lyocell produced through solution blending. The results showed that blends with PVA exhibit the best tensile properties. Thus, Lyocell fibers have recently been used as reinforcement for thermoplastic fiber composites. 

Dielectric loss e" of miscible blends of poly(2-chlorostyrene) (P2CS450 Mp2cs = 4.5 x 10 ) and poly (vinyl methyl ether) (PVME96 Mpvme = 9.6 x 10 ) with various P2CS volume fractions ( )p2cs measured at 1 kHz at various temperatures. (Data taken, with permission, from Urakawa, O., Y. Fuse, H. Hori, Q. Tran-Cong, and O. Yano. 2001. A dielectric study on the local dynamics of miscible polymer blends Poly(2-chlorostyrene)/poly(vinyl methyl ether). Polymer 42 765-773.)... 

Urakawa, O., Y. Fuse, H. Hori, Q. Tran-Cong, and O. Yano. 2001. A dielectric study on the local dynamics of miscible polymer blends Poly(2-chlorostyrene)/ poly(vinyl methyl ether). Polymer 42 765-773. 

Huang, C. W., C. A. Wu, S. S. Hou, P. L. Kuo, C. T. Hsieh, and H. S. Teng. 2012. Gel electrolyte derived from poly(ethylene glycol) blending poly(acrylonitrile) applicable to roll-to-roll assembly of electric double layer capacitors. Advanced Functional Materials 22 4677-4685. 

Asymmetric blend poly(ether sulfone)-polyimide (PES-PI) hollow fiber membranes were prepared at different air gaps and used for gas separation [23,24]. It was observed that the permeance of CO2 and N2 increased with an increase in air gap while the ideal selectivity decreased when the hollow fibers were uncoated. After silicone coating, no significant change was observed either in permeance or in the permeance ratio. Although the feed gas was supplied to the shell side of the hollow fiber, it seems that the skin layer is on the lumen side when the SEM pictures are examined. From AFM [25], it was observed that the mean roughness parameter of the inner surface (uncoated lumen side) increased with an increase in the air gap. 

Poly (hexamethylenebiquanide) hydrochloride microbicide, cotton blends Poly (hexamethylenebiquanide) hydrochloride microbicide, curtains... 

Poly (hexamethylenebiguanide) hydrochloride preservative, cotton blends Poly (hexamethylenebiguanide) hydrochloride preservative, cough syrups Cetylpyridinium chloride preservative, creams/lotions Chlorhexidine digluconate Lichen (Usnea barbata) extract preservative, cured food Sodium nitrate Sodium nitrite preservative, curtains... 

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