Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Poly solution properties

Solubility and Solution Properties. Poly(vinyhdene chloride), like many high melting polymers, does not dissolve in most common solvents at ambient temperatures. Copolymers, particularly those of low crystallinity, are much more soluble. However, one of the outstanding characteristics of vinyUdene chloride polymers is resistance to a wide range of solvents and chemical reagents. The insolubiUty of PVDC results less from its... [Pg.432]

However, except for two reports of preliminary results on poly-DSP (Fujishige and Hasegawa, 1969 Kanetsuna et al., 1970), there are few reports so far which describe the film and solution properties of the polymers obtained by four-centre-type photopolymerization. [Pg.126]

Hyperbranched poly(ethyl methacrylate)s prepared by the photo-initiated radical polymerization of the inimer 13 were characterized by GPC with a lightscattering detector [51]. The hydrodynamic volume and radius of gyration (i g) of the resulting hyperbranched polymers were determined by DLS and SAXS, respectively. The ratios of Rg/R are in the range of 0.75-0.84, which are comparable to the value of hard spheres (0.775) and significantly lower than that of the linear unperturbed polymer coils (1.25-1.37). The compact nature of the hyperbranched poly(ethyl methacrylate)s is demonstrated by solution properties which are different from those of the linear analogs. [Pg.17]

Experimental data on the solution properties and melt rheology of highly branched structures are scarcely found in the literature. This might be because of the structural nonuniformity of hyperbranched polymers, which makes it difficult to obtain reliable data. Because of the purely statistical nature of the poly-... [Pg.17]

The first report on the temperature-dependent solubility of PVCL was published in 1968 by Solomon et al. [271]. Up to the 1990s, most studies on PVCL originated from groups in the former Soviet Union. These early studies are reviewed in Kirsh s book [151] on poly(N-vinylamides). Recently, PVCL and its solution properties have been scrutinised anew, in view of the noted bio-... [Pg.50]

Polyammonium-containing ligands, 24 44 Polyammonium macropolycycles, 76 780 Polyampholytes, 20 475 479 solution properties of, 20 479 synthesis of, 20 477- 478 Poly(anhydrides), bioresorbable polymers, 3 740... [Pg.724]

PolyCy-benzyl L-glutamate) (PBLG), 15 109 Poly(y-ketosulfide)s, optically active, 23 711 Poly(P-alanine), 1 292 Poly-P-hydroxybutyrate (PHB), 12 482 Polybetaines, 20 479-482 applications of, 20 482 preparation of, 20 480-481 solution properties of, 20 481-482 synthesis of, 20 479-481 Polyborates, 4 256-258 Polyborosiloxanes, in silicon carbide manufacture and processing, 22 533 Polybrominated diphenyl ethers (PBDEs), 13 142-143 20 56... [Pg.725]

The solution properties of dendrigraft polybutadienes are, as in the previous cases discussed, consistent with a hard sphere morphology. The intrinsic viscosity of arborescent-poly(butadienes) levels off for the G1 and G2 polymers. Additionally, the ratio of the radius of gyration in solution (Rg) to the hydrodynamic radius (Rb) of the molecules decreases from RJRb = 1.4 to 0.8 from G1 to G2. For linear polymer chains with a coiled conformation in solution, a ratio RJRb = 1.48-1.50 is expected. For rigid spheres, in comparison, a limiting value RJRb = 0.775 is predicted. [Pg.220]

Winnik, F. M., Davidson, A. R., Hamer, G. K., and Kitano, H. Amphiphilic poly(A-isopropylacrylamide) prepared by using a lipophilc radical initiator Synthesis and solution properties in water. Macromolecules, 1992, 25, 1876-1880. [Pg.49]

Based on the solution property of poly (DMAEMA-co-AAm) in response to temperature, the temperature dependence of equilibrium swelling of poly (DMAEMA-c6>-AAm) gel as a function of chemical composition was observed as shown in Figure 6. The transition temperature of copolymer gel between the shrunken and swollen state was shifted to the lower temperature with increases in AAm content in the gel network. This is attributed to the hydrogen bond in the copolymer gel network and its hydrophobic contribution to the LCST Copolymer II gel was selected as a model polymer network for permeation study because it showed the sharp swelling transition around 34°C. [Pg.60]

Surprising effects can also be observed when solvent mixtures are used to dissolve a polymer. There are examples where mixtures of two non-solvents act as a solvent vice versa, a mixture of two solvents may behave like a non-solvent. For example, polyacrylonitrile is insoluble in both, nitromethane and water, but it dissolves in a mixture of the two solvents. Similar behavior can be observed for polystyrene/acetone/hexane and poly(vinyl chloride)/acetone/carbon disulfide. Examples of systems where the polymer dissolves in two pure solvents but not in their mixture are polyacrylonitrile/malonodinitrile/dimethylforma-mide and poly(vinyl acetate)/formamide/acetophenone. These peculiarities are especially to be taken into account if one wants to adjust certain solution properties (e.g., for fractionation) by adding one solvent to another. [Pg.17]

Namazi H, Adeli M. Solution properties of dendritic triazine/poly(ethylene glycol)/dendritic triazine block copolymers. J Polym Sci Part A Polym Chem 2005 43 28-41. [Pg.302]

In this paper, we report the solution properties of sodium dodecyl sulfate (SDS)-alkyl poly(oxyethylene) ether (CjjPOEjj) mixed systems with addition of azo oil dyes (4-NH2, 4-OH). The 4-NH2 dye interacts with anionic surfactants such as SDS (11,12), while 4-OH dye Interacts with nonionic surfactants such as C jPOEn (13). However, 4-NH2 is dependent on the molecular characteristics of the nonionic surfactant in the anlonlc-nonlonic mixed surfactant systems, while in the case of 4-OH, the fading phenomena of the dye is observed in the solubilized solution. This fading rate is dependent on the molecular characteristics of nonionic surfactant as well as mixed micelle formation. We discuss the differences in solution properles of azo oil dyes in the different mixed surfactant systems. [Pg.69]

N 025 "Solution Properties of Synthetic Polypeptides. V. Helix-Coil Transition in Poly(p-benzyl-L-asparate)"... [Pg.423]

An early review of micellization in block copolymers was presented by Tuzar and Kratochvfl (1976), and these authors have recently provided an excellent review of the literature up to 1992 (Tuzar and Kratochvfl 1993). Micellar properties of block copolymers were also reviewed by Price (1982). A discussion of micellization was included in the general reviews on block copolymers by Riess et al. (1985) and Brown et al. (1989). Excellent reviews focussed on the solution properties of a particular class of copolymer, i.e. copolymers of polyoxyethylene) with poly(oxypropylene) have been presented by Alexandridis and Hatton (1995) and by Chu (1995) and Chu and Zhou (1996). Micellization and micellar association in related poly(oxyethylene)/poly(oxybutylene) copolymers have been summarized by Booth et al (1997). [Pg.132]

Although the crystalline poly(allyl isocyanate) polymers are reported to be stable, many of these polymers depolymerize upon heating to yield monomers and cyclic trimers. The level of temperature sensitivity is a strong function of the length of the side chain. Room temperature depolymerization occurs in polar solvents in the presence of an initiator. Interestingly, the solution properties of poly(alkyl isocyanates) display an unusual degree of chain stiffness which is attributed to their helical configuration (64). [Pg.451]

An investigation of the solution properties of poly-acrylonitriles produced by anionic polymerization and by radical polymerization seem to indicate that the former is a branched polymer while the latter is a linear polymer. The amount of branching seems to increase with rising temperature of polymerization and this suggests a termination due to a proton transfer from the polymer followed by polymerization that starts on the resulting negative center of the previously formed polymer. This leads to the formation of a branch. [Pg.281]

Gohy et al. studied the solution properties of micelles formed by two polystyrene-frZock-poly(2-vinylpyridine)-block-poly(ethylene oxide) (PS-b-P2VP- -PEO) copolymers in water by dynamic light scattering and transmission electron microscopy [92]. Spherical micelles were observed that consist of a PS core, a P2VP shell and a PEO corona. The characteristic sizes of core, shell and corona were found to depend on the copolymer composition. The micellar size increased at pH<5 due to P2VP block protonation (Fig. 19). [Pg.196]

Poly( ethylene oxide)-block-poly (propylene oxide)-hZock-poly(ethylene oxide)-g-poly(acrylic acid) (PEO-fc-PPO-fc-PEO-g-PAA, Pluronic-PAA) graft copolymers were synthesized by free radical grafting copolymerization of acrylic acid monomers onto PEO-h-PPO-h-PEO (Pluronic F127) and the aqueous solution properties were characterized by Bromberg [133, 134]. Chiu et al. [135] reported on the micellization of (non-ionic) poly(stearyl methacrylate)-gra/f-poly(ethylene glycol) graft copolymers. [Pg.204]

In order to clarify the solution properties of poly(VAd) in more detail, poly(VAd) was fractionated by ultrafiltration techniques. The observed molar extinction coefficient of poly(VAd) apparently decreases with an increase in the average molecular weight (Table 13). This suggests that the possibility of an inter-... [Pg.128]

C 6 Chinai, S. N. Poly-n-hexyl methacrylate. IV. Dilute solution properties by viscosity and light scattering. J. Polymer Sci. 25, 413 (1957). [Pg.98]


See other pages where Poly solution properties is mentioned: [Pg.451]    [Pg.13]    [Pg.26]    [Pg.49]    [Pg.81]    [Pg.215]    [Pg.35]    [Pg.47]    [Pg.37]    [Pg.37]    [Pg.38]    [Pg.68]    [Pg.74]    [Pg.123]    [Pg.272]    [Pg.141]    [Pg.186]    [Pg.435]    [Pg.189]    [Pg.221]    [Pg.244]    [Pg.58]    [Pg.108]    [Pg.149]    [Pg.192]    [Pg.193]    [Pg.108]   
See also in sourсe #XX -- [ Pg.437 ]

See also in sourсe #XX -- [ Pg.167 , Pg.169 ]




SEARCH



Poly , properties

Poly , solution

Solute property

Solution properties

© 2024 chempedia.info