PCL carbonyl

FTIR studies have shown the development of an additional carbonyl stretching vibration for PCL carbonyl at 1725 cm in blends of PCL with phenol formaldehyde resin [88]. 

Not yet obtained in satisfactory purity prepared by metathetical reaction from (PCls)s-Mo(CO)a (2) with potassium fluorosulfinate. In addition to carbonyl absorptions, infrared spectrum exhibits only strong P—F stretching absorptions at 852 cm. -1 (m), 867 cm,-1 (vs), and 880 cm. (sh), in the region for phosphorus trifluoride (10),... 

There is no doubt that this dispersion effect occurs but the magnitude of the spectral differences appear in most cases to be considerably larger than would be predicted by dispersion effects. For example, the poly(e-caprolactone) (PCL) and poly (vinyl chloride) (PVC) blend has been studied 252,253) and for this system the refractive indices are identical. In this case, there are obvious frequency shifts and broadening of the carbonyl band as a function of PVC concentration as shown in (Fig. 21). Nine percent of the original area of the carbonyl peak is involved in the shifted frequency absorption. Clearly, for this system, chemical interaction effects are being observed. In fact, PCL can be viewed as a macromolecular plasticizer for PVC. The blend system polyO-propiolactone) PPL and PVC was studied 2S3). In contrast to the PCL/PVC system, the PPL/PVC system was incompatible over the entire range of compositions. 

Chlorinated Fatty Acids. Chlorination of carboxylic acids is much more difficult because the contribution or the carbonyl group toward proton removal is offset by the electron donation effect from the hydroxyl group. This hindrance is obviated by reaction with the acid chloride or anhydride. Chlorination is normally accomplished hy use of n catalyst, such as phosphorus trichloride. Monochloroacelic acid is an important industrial chemical. Dichloro- and trichloroacetic acids can he produced by further chlorination, although the latter can be produced convenienlly by nitric acid oxidation of chloral. Higher chlorinalcd tally acids can be produced by treatment or the hydroxy carboxylic acid or ester with HCI ur PCL ... 

Savb et al. (2006) report a method to evaluate micelle integrity irottitro andin vivo. PEO-b-PCL micelles were synthesized with a Luorogenic dye, Luorescein-5-carbonyl azide diacetate, covalently attached to the PCL block. In the hydrophobic core of intact micelles, the dye remained... 

Compatible and incompatible polyester - PVC blends have been considered. Examples include systems, poly-X-caprolactone (PCL)/PVC which are compatible [5,28], in the melt and exhibit partial compatibility in solid state and poly-P-propiolactone (PPL)/PVC blends which are known to be incompatible [5, 28]. Figure 5.9 shows the infrared spectra of the carbonyl stretching vibration (in the range 1600-1800 cm-1) for the different blends. 

Specific interactions between PCL and PVC are clearly indicated. In the solid state (Figure 5.9a) the spectrum of neat PCL indicates the presence of crystalline (1724 cm 1) and amorphous (1737 cm"1) bands. At mole ratios up to 2 1 of PVC to PCL, the spectra indicate that in the solid state the blends consist of crystalline and amorphous phases. As the PVC concentration increases, a parallel increase of the intensity of the amorphous band is observed. Moreover, the frequency shifts observed for both the crystalline and amorphous bands as a function of the composition of the blend suggests that specific interactions between the two polymers occur. No shift is observed in the carbonyl stretching vibration of PPL/PVC blends, in the molten state or in the solid state over the entire range of compositions and the two polymers are incompatible [28]. 

The orientation of the two components of a compatible (1), amorphous 50% NC blend is shown in Figure 4. The films have been strained to 25, 50, and 75% in successive cycles, with each strain increment followed by a relaxation to zero stress. The orientation of the PCL and NC have been followed by using the carbonyl (1,728 cm 1) and N02 (1,660 cm 1) stretching peaks, respectively. 

The orientation functions for a 75/25 PVC/PCL blend are presented in Figure 5, which shows that the PCL chains in the 75% PVC blend orient in essentially the same way as the isotactic segments and the other folded-chain PVC segments represented by the 693 cm 1 peak. This peak is shifted from 691 cm 1 for pure PVC. The shape and magnitude of the orientation functions for the carbonyl and 693-cm"1 C-Cl peak are similar to the orientation functions shown for the amorphous 50% NC blend. 

Figure 7 shows CO2 evolution from the PET films with different thermomechanical histories and consequent differences in film thickness, ciystallinity and molecular orientation (9). In all three cases strong CO2 generation was observed and could be measured with good repeatability. Similar measurements have been made on poly(8-caprolactone) (PCL) and on PCL/PVC blends (10). These measurements on different polyesters demonstrate the applicability of the CO2 method to materials for which carbonyl absorption measurement is not very suitable. 

In general in the preparation of imide chlorides excess PCls should not be used if a-chlorination is undesired. In contrast to triple bonds, double bonds conjugated with the amide carbonyl group do not add the HCl set free in the course of imidoyl chloride formation. In the case of a,a,a-trihalogenated amides... 

Mirau and White applied the HETCOR pulse sequence to PMA/PVPh, PMMA/PVPh and PC/polycaprolactone (PCL) blends [26, 124]. Figure 10.16(b) shows the HETCOR spectrum for PMA/PVPh = 1/1 cast from methyl ethyl ketone. The combined use of WIM-24 and MAS allows CP for H and C spins in close proximity, therefore, most of the cross-peaks appear between directly bonded C— H pairs. Interestingly, a cross-peak was observed for the nonprotonated carbonyl carbon of PMA. The spectrum shows... 

In two recent publications we reported Fourier transform infrared (FTIR) studies of the blend systems poly(e-caprolactone) (PCL) - poly(vinyl chloride) (PVC) and poly(3-proprolactone) (PPL) - PVC. The former blend system is known to be compatible in the amorphous state and our FTIR studies demonstrated that frequency shifts and band broadening of the carbonyl band associated with PCL occur in blends containing PVC in the molten and... 

The infrared spectrum of PCL in the solid state (semicrystalline) and molten (amorphous) state has been presented previously. Also included in this previously published work was the infrared spectrum of the preferred ( crystalline ) conformation of PCL obtained by digital subtraction of the amorphous from that of the semi-crystalline spectrum. Of particular interest to this work was the different frequencies observed for the carbonyl stretching vibration in the preferred (1724 cm ) and amorphous (1737 cm ) conformations. ... 

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