PoIy blends

THPC—Amide—PoIy(vinyI bromide) Finish. A flame retardant based on THPC—amide plus poly(vinyl bromide) [25951-54-6] (143) has been reported suitable for use on 35/65, and perhaps on 50/50, polyester—cotton blends. It is appUed by the pad-dry-cure process, with curing at 150°C for about 3 min. A typical formulation contains 20% THPC, 3% disodium hydrogen phosphate, 6% urea, 3% trimethylolglycouril [496-46-8] and 12% poly(vinyl bromide) soUds. Approximately 20% add-on is required to impart flame retardancy to a 168 g/m 35/65 polyester—cotton fabric. Treated fabrics passed the FF 3-71 test. However, as far as can be determined, poly(vinyl bromide) is no longer commercially available. 

Jamieson and McNeill [142] studied the degradation of poIy(vinyI acetate) and poly(vinyI chloride) and compared it with the degradation of PVC/PVAc blend. For the unmixed situation, hydrogen chloride evolution from PVC started at a lower temperature and a faster rate than acetic acid from PVAc. For the blend, acetic acid production began concurrently with dehydrochlorination. But the dehydrochlorination rate maximum occurred earlier than in the previous case indicating that both polymers were destabilized. This is a direct proof of the intermolecular nature of the destabilizing effect of acetate groups on chlorine atoms in PVC. The effects observed by Jamieson and McNeill were explained in terms of acid catalysis. Hydrochloric acid produced in the PVC phase diffused into the PVAc phase to catalyze the loss of acetic acid and vice-versa. 

By modifying the functional groups they can be used,for example, as crosslinkers in high solid or powder coatings and in thermosets. Because of their good miscibility and low melt viscosity, they find applications as melt modifiers and as blend components. Modified hyperbranched polymers, like alkyl chain substituted poiy(ether)s and po-ly(ester)s sometimes exhibit amphiphilic behavior.They can, therefore, be used as carriers for smaller molecules,for example, dyestuff into polypropylene. 

The rather unexpected properties described above seem to be peculiar to PVN, for none of the blends with polystyrene, poIy-4-vinylbiphenyl, and polyacenaphthylene contained significant amounts of amorphous PEO. The modulus curves for these systems are characteristic of blends of incompatible polymers. The photomicrograph in Figure 12 illustrates the different morphologies of PVB and PEO blends. The reason for the apparently different behavior for these polymers as compared with PVN is not yet understood. But there is strong evidence from dilute solution-studies that the conformational properties for these polymers differ markedly. 

H. Ohme, S. Kumazawa, and J. Kumaki, Heat-resistant polyllactic acid)-poIy-acetal blend with good processability, mechanical strength, and transparency for plastic moldings, films, and fibers, WO 2003014224 Al, assigned to Toray Industries, Inc., Japan, February 20, 2003. 

Luranyl BASF PoIy(ethyIene oxide) blend... 

Starch PoIy(ethyIene-vinylalcohol) copolymer, 56% VA waxy maize, native com and high-amylose starches extrusion-blended x-ray, DSC, SEM, TEM Phase separated starch domains. Oriented droplets, 0.05-5 jm in length (waxy maize), 0.05-1.2 pm domains (native com), <0.25 pm (high amylose) (81)... 

Nylon 4,6 PoIy(ethylene-vinyIaIcohoI) copolymer, 27 moI% elhylene, 13 moI% vinyl acetate nylon 4/nylan 6 69/ 31 mol% films cast from formic acid FT-IR, X-ray, DSC, tensile tests Miscible when nylon 4>6 <35 wi%.C-0-N-H hydrogen bond between nylon and EVOH. Increase in tensile strength from 4 for 15/85 wt% nylon/EVOH to 331kgcm for 100/0 blend (82)... 

It has been found that blends of a poly(biphenyl ether sulfone) and a second poIy(arylene ether sulfone) based on bisphenol A are most suitable for plumbing applications. The blend has an outstanding resistance to hot water [149]. 

Morgado, J., R.H. Friend, and F. Cadalli. 2002. Improved efficiency of light-emitting diodes based on polyfluorene blends upon insertion of a poIy(p-phenylene vinylene) electron-confinement layer. Appl Phys Lett 80 (14) 2436-2438. 

We illustrate the theory with blends of copoly (styrene acrylonitrile) + poIy(me-thyl methacrylate) and those of co poly (styrene acrylonitrile) + copoly(butadiene acrylonitrile), for which experimental data are available from literature [76,77]. The quantities s, ..., Sj may be estimated from van der Waals surfaces used in the UNIFAC-tables [78] or from an empirical fit to the available experimental data. The G parameters, a, b, c, d, have to be adjusted to fit experimental cloud-points or critical point and/or spinodal curve. The gy parameters in Eq. (155) may be obtained from thermodynamic data sensitive to them or from the cloud-point curve of subsystems, if available. 

FIGURE 20.17. (a) Series of spin-diffusion Hetcor data for poiycarbonateatmixingtimesof(top)0 ms, (middle) 0.1 ms, and (bottom) 2.0 ms. (b) Representative spin-diffusion curves extracted from Hector spin-diffusion data, like that in (a), for two different poly( -caprolactone)/poiy-(L-lactic acid) biends. Note the ciear distinction between intramolecular and interchain/interdomain equilibration, the latter occurring at longer times for one blend versus the other. [Adapted with permission from Refs. [62] and [63]. 

PVPh/PVAc, EVAc, PCL, PPL, PMA, PEA, PBA, or P2EHA Poiy(4-vinyl phenol) blends the amount of free and bonded C = 0 vibrations were determined fort the PVPh/hydrogen-bonding polymer blends, using a curve fitting procedure 13... 

Kuo, C. M. Clarson, S. J., Investigation of the Interactions and Phase Behavior in Poly(dimethylsiloxane) and PoIy(methyIphenyIsiloxane) Blends. Macromolecules 1992, 25, 2192-2195. 

Zheng H, Du Y, Yu J et al (2001) Preparation and characterization of chitosan/poIy(vinyi alcohol) blend fibers. J Appl Poiym Sci 80 2558-2565... 

Poly(vinyl chloride) with a head-to-head structure has been prepared by chlorination of cu-polybuta-l, 4-diene and its thermal degradation was studied by a number of methods. The threshold temperature for breakdown was lower than that for normal poIy(vinyl chloride but higher temperatures were required to attain maximum rates. The same school has also studied decomposition of blends of poly(vinyl chloride) with various acrylates. The most important interactive effects occur when a small reactive entity produced by breakdown of one of the polymers diffuses into and reacts with the second. 

Many of the studies of multiphase polymers are conducted on unsaturated rubbers which are adequately stained by osmium tetroxide, which reveals the nature of the dispersed phase domains. Polymers with activated aromatic groups have been selectively stained by reaction with mercuric trifluoroacetate (Section 4.4.8). Hobbs [262] has successfully used this technique to provide contrast in blends of poIy(2,6-dimethyl-l,4-phenylene oxide) and Kraton G (SBS block copolymer). Although this stain is effective in enhancing contrast, a drawback of the method is that the material is not hardened or fixed by the stain. 

Figure 24 Periodic noncentrosymmetric lamellar superstructure of a blend of polystyrene-block-polybutadiene-block-poiy(tert.butyl methacrylate) S-B-T with polystyrene-block-poly(tert.butyl methacrylate) S-T with the composition 50 mol% S-B-T 50mol% S-T. (a) Transmission electron micrograph (stained with OSO4), (b) scheme of the characteristic defect proving the periodic noncentrosymmetry. (From T. Goidacker et ai. Wafure 398 137, 1999, Copyright 1999 Macmillan Magazines Ltd.)...

PEO) with isotactic poly(methyl methacrylate) (PMMA) [25, 32] and labeUed (both random and chain-end) PMMA with poIy(vinylidene fluoride) (PVDF) [33, 34]. These are complex systems because they show partial miscibility and because in each case one of the components is capable of crystallising. Nevertheless, these authors obtained fundamental information on the morphology of the blend and phase separation. In the PEO-PMMA blends, the spectra were of the composite type, and they ascribed the fast- and slow-motion spectra to nitroxides located in PEO-rich regions and PMMA-rich regions respectively. 

O. A. Gallagher, R. Jakeways, and L M. Ward, The structure and properties of drawn blends of poiy(vinylideoc fluoride) and poly(meihyl melhactylaie)./. Polymer. Sd Part B Polymer Pkys. 29 1147(1991). 

PoIy(vinyl chloride), PVC, is one of the most versatile of polymers, and the following forms have important applications rigid (unplasticized) grades, plasticized compounds, copolymers and blends. This is perhaps surprising since it is one of the least stable polymers, for which reason much of the early development was concerned with copolymers and with plasticized compositions. 

Figure 3.8 Reactive extrusion compatibiiization of poiy(vinyi aicohol)(PVOH) and ethylene propylene rubber (EPR) comparison of stress-strain data of control blend versus reactive compatibiiized blend (reproduced (replotted) with permission of reference Robeson, L. M., Famiii, A., and Nangeroni, J. F., In Science and Technology of Polymers and Advanced Materials, Prasad, P. N., (Ed.), (1998) Plenum Press New York p. 9 with kind permission of Springer Science and Business Media)...

Uses Wool scouring agent/degreaser emulsifier, detergent for poiy/cotton blend scouring... 

Chem. Descrip. Emulsified aromatic hydrocarbon Ionic Nature Nonionic Uses Dye carrier for poiy/wooi blends Properties Liq. 100% cone. 

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