Copolymer solubility

One of the major goals of this endeavor was to solubilize the normally intractable polyimides by the incorporation of siloxane segments, and, optionally, by solution imidization. Solubilities of a series of siloxane-modified polyimide copolymers were evaluated in a variety of solvents as indicated in Table I. Copolymer solubility was found to be a function of the siloxane oligomer concentration... 

The copolymers were obtained following this method by exploiting the similarity of 5-vinylborazine and styrene. Several poly(styrene-co-B-vinylborazine) copolymers soluble in ethers were formed in solution at 80°C using AIBN.28... 

The copolymerization of multimonomers with vinyl monomers such as acrylic acid, styrene, or acrylonitrile results in semi-ladder copolymers soluble in many common sol-vents. Such products consist of ladder-type blocks created from multimonomer molecules and blocks of repeated units formed from vinyl monomer, both connected with branching points and fastened together by fragments of the molecule with ladder structure. Semi-ladder copolymer (multimethacrylate-acrylic acid, partially crosslinked) has the following structure ... 

It is well known that the solubility of polymers depends on their molar mass. This effect can be utilized for the evaluation of molar-mass distributions. With copolymers, solubility is determined by composition and molar mass. Topciev et al. derived the equation ... 

Graft copolymer Soluble Soluble Colored, Insoluble Soluble Soluble Insoluble... 

Hydride polyaddition of divinyl-containing compounds was carried out for various lengths of a,co-dihydridedimethylsiloxanes. The reaction run was searched by a decrease of active =Si-H groups concentration. It was found that for rhodium acetylacetonatedicarbonyl as a catalyst, copolymers soluble in organic solvents were obtained, which were structured after some time. This may be explained by the fact that in spite of polymers re-precipitated from toluene solution by methyl alcohol, rhodium catalyst remains in polymeric systems, which decompose and induce structuring (cross-linking) of copolymers. 

The classical approach is based on the dependence of copolymer solubility on composition and chain length. A solvent/nonsolvent combination fractionating solely by molar mass would be appropriate for the evaluation of MMD, another one separating with respect to chemical composition would be suited for determining CCD or FTD. However, in reality, precipitation fractionation yields fractions which vary both in chemical composition and molar mass. Even high resolution fractionation would not improve the result. Narrower fractions can be obtained by cross-fractionation separating in two different directions. However, even in this case, it is almost impossible to obtain perfectly homogeneous fractions. 

PVP forms molecular adducts with many substances. Insoluble complexes are formed when aqueous solutions of PVP are added to tannic acid, poly(acrylic acid) and methyl vinyl ether-maleic anhydride copolymer. Soluble complexes, called iodophors, are formed with iodine the solubility of iodine is increased from 0.034% in water at 25°C to 0.58% by 1% PVP. The resulting iodophor retains the germicidal properties of iodine. It is thought that the iodine is held in a PVP helix in solution. The influence of two samples of PVP on the solubility of testosterone is shown in Fig. 8.21. The PVP correspondingly increases the rate of solution of the steroid from solid dispersions. 

The AMPS/AM copolymer can be used under 90°C (Luo et al., 2006). It also had better salinity tolerance. Zhao et al. (2006) reported that the AM/ AMPS solution viscosity was about twice the HPAM viscosity at the same conditions, when the salinity was increased. However, AMPS products are more expensive than HPAM. Zhao et al. (2005b) reported that AMPS copolymer solubility was lower than HPAM (10 hours of dissolution time in fresh water compared with 2 to 4 hours for HPAM). 

Polymerization of Cyclic Ethers and Formats by Poly-THF Dioxolenium Salt. The polymerization of cyclic ethers and formals by PTHF-dioxolenium salt was carried out to clarify the presence of termination or transfer reactions. The results are shown in Table IV. In the polymerization of 3,3-bischloromethyloxetane (BCMO), block copolymer soluble in chloroform and having the expected molecular weight was formed the homopolymer of BCMO insoluble in chloroform was not observed. The block copolymer showed crystalline bands of BCMO at 700, 860, and 890 cm 1, suggesting the formation of ABA block. 

In the polymerization of 7-oxa [2.2.1]bicycloheptane (OBH), the formation of block copolymer soluble in chloroform and homopolymer... 

Yamashita et al. modified the polystyryl end-groups by introducing carboxylate anions (by reaction with C02) 135). After coupling this modified polySt with a living polyTHF and removing polyTHF by extraction with hot isopropanol, a solid copolymer, soluble in common organic solvents and having the structure ... 

H NMR speetra were leeorded on a Bruker AC 400 speetrometer. Apparent molar masses were determined by size exelusion ehromatography (SEC) either in THF or H2O. For dibloek copolymers soluble in THF, the deviee was equipped with a Jaseo PU-980 pump, a PSS eolunm (8 300 mm. 

Table 1.2 indicates that in a series of copolymers, solubility improves with a decrease in the fraction of perylenecarboximide nnits. A copolymer containing 20 mol% perylenecarboximide rings exhibits good solubility in chloroform, whereas a copolymer bearing 80 mol% of these... 

Krause S. 1991. On the intramolecular repulsion effect in random copolymer solubility. Macromolecules 24 2108. 

Anionic copolymerizations are very useful in forming block copolymers. (See Chapter 5 for discussion.) Ziegler-Natta catalysts also form block copolymers, similarly to anionic initiators. Much work on copolymerization with coordinated anionic initiators was done to develop ethylene propylene copolymers. Ethylene is considerably more reactive in these copolymerizations. To form random copolymers, soluble Ziegler-Natta catalysts are used. This is aided further by carefully controlling the monomer feed. ... 

Sodium DVB/acrylates copolymer Sodium hyaluronate Sodium polyacrylate starch Sodium polymethacrylate Sodium polystyrene sulfonate Sodium PVM/MA/decadiene crosspolymer Sodium styrene/acrylates copolymer Sodium tauride acrylates/acrylic acid/acrylonitrogens copolymer Soluble collagen Starch/acrylates/acrylamide copolymer Starch diethylaminoethyl ether Steareth-10 allyl ether/acrylates copolymer Stearylvinyl ether/MA copolymer ... 

Details are given of the polymerisation of fluoroalkyl acrylate miniemulsions to produce fluorinated latexes. Copolymerisation reactions were also performed with standard hydrophobic and hydrophilic monomers to produce either core-shell latexes or statistical copolymers. Solubilities, molecular weights and particle sizes were investigated. 19 refs. 

Ciampelli and co-workers [2] have developed two methods based on infrared spectroscopy of carbon tetrachloride solutions of polymers at 7.25, 8.65, and 2.32 pm for the analysis of ethylene-propylene copolymers containing greater than 30% propylene. One method can be applied to copolymers soluble in solvents for infrared analysis, the other can be applied to solvent-insoluble polymer films. The absorption band at 7.25 pm due to methyl groups is used in the former case, whereas the ratio of the band at 8.6 pm to the band at 2.32 pm is used in the latter. Infrared spectra of polymers containing 55.5 and 85.5% ethylene are shown in Figure 3.1. 

Poly(methacrylic acid. Eudragit L Anionic copolymers. Soluble Enteric coalings resistant to... 

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