Spectroscopy anhydride copolymer

Hydrolysis of styrene-methacrylic anhydride copolymers. One gram samples of the copolymers were suspended in distilled water (150 ml.) and the mixtures were refluxed, with stirring, until solutions were obtained that were stable at room temperature. Copolymers with high styrene contents hydrolyzed slowly and required 108 hr. reaction times. These polymers formed soap-like solutions when completely hydrolyzed. The hydrolyzed polymers were isolated by freeze-drying and were examined by infrared spectroscopy to establish the completeness of hydrolysis. 

Preparations of azide derivatives from styrene-maleic anhydride copolymers, cellulose, and gelatin by attaching aromatic azide compounds are described in the literature. Most of the resultant polymers crosslink rapidly when exposed to light of 260 wavelength. Also, as much as 90% of the hydroxy groups of poly(vinyl alcohol) can be esterified withp-azido-benzoyl chloride. These reactions must be carried out in mixtures of chloroform and aqueous sodium hydroxide. Based on infrared spectroscopy, the following crosslinking mechanism was proposed ... 

According to Jakisch et al. [79], FTIR spectroscopy is the preferred method for in-line investigation polymer melts and polymer melt reac-tions/kinetics, allowing quantitative determination of all components. FTIR analysis of compound melts enables additive level stability and effectiveness to be observed over multiple extrusion passes. The use of the ATR principle is suitable for in-line analysis of polymer melts in the extruder. The exit of the extruder was equipped with an on-line IR transmission process control system consisting of a 150 /um thick ZnSe melt flow cell. Characteristics of such systems have been described [71,74]. Another process spectrometer with an in situ ZnSe-ATR dipper probe was mounted at different positions in the extruder. For in-line ATR the residence time plays no role. Only the first 5 /xm (corresponding to the penetration depth of the IR radiation) are examined. Minor components are thus detected with difficulty. Jakisch et al. [79] monitored the conversion of styrene-maleic anhydride copolymers (SMA) with fatty amines into styrene-maleimide copolymer (SMI) during reactive extrusion by means of FTIR. In principle, both mid-IR and near-IR spectroscopy with ATR, transmission and diffuse reflectance probes are suitable for quantitative on- and in-line process analysis of multicomponent polymer... 

The 1 1 copolymer so obtained has alternating monomeric units of styrene and maleic anhydride.This can be verified by NMR spectroscopy.lt is insoluble in carbon tetrachloride, chloroform, toluene, and methanol, but soluble inTHF,1,4-dioxane,and DMF.lt can be hydrolyzed to a polymeric acid (see Example 5-3)... 

The formation of block copolymers from styrene-maleic anhydride and acrylic monomers was also indicated by pyrolytic gas chromatography and infrared spectroscopy. A comparison of the pyrograms of the block copolymers in Figure 7 shows peaks comparable with those obtained when mixtures of the acrylate polymers and poly(styrene-co-maleic anhydride) were pyrolyzed. A characteristic infrared spectrum was observed for the product obtained when macroradicals were added to a solution of methyl methacrylate in benzene. The characteristic bands for methyl methacrylate (MM) are noted on this spectogram in Figure 8. 

Macroradicals obtained by the heterogeneous copolymerization of styrene and maleic anhydride in poor solvents such as benzene were used to initiate further polymerization of selected monomers. This technique was used to produce higher molecular weight alternating copolymers of styrene and maleic anhydride and block copolymers. Evidence for the block copolymers was based op molecular weight increase, solubility, differential thermal analysis, pyrolytic gas chromatography, and infrared spectroscopy. 

Marie et al. [49] also studied the in-situ block copolymer formation via reactive blending of functionalized homopolymers. In their work, blends were characterized by SEM, DSC and dynamic mechanical spectroscopy (DMS). It should be noted that their blends (PA-6/PDMS and PS/PDMS) were composed totally using functionalized homopolymers. The different reactions under investigation were amine(NH2)/anhydride(An), amine(NH2)/epoxy(E) and carboxylic acid(COOH)/epoxy(E) (Fig. 5). 

An electron acceptor such as maleic anhydride forms complexes with many donors, amongst which is vinyl acetate [80, 189, 190], Its existence at 363 K was proved by UV spectroscopy, ll NMR and by the formation of an alternating copolymer [80]. The complex is not formed above 363 K. From the two monomers, a statistical copolymer is formed, its composition depending on the ratio of initial monomer concentrations. 

Zeng W and Shirota Y (1989) Studies on alternating radical copolymerization analysis of microstructures of styrene-maleic anhydride, styrene-acrylonitrile, and styrene-methyl methacrylate copolymers by fluorescence spectroscopy. Macromolecules 22 4204-8. 

The copolymerization of methacrylic anhydride with styrene has been investigated by several groups. With the exception of Smets, et al. (12) it has been reported that the methacrylic anhydride units in the polymers are almost completely cyclized. This is also in accord with our experience. It proved difficult to separate unpolymerized methacrylic anhydride from the copolymers, and considerable effort was made to remove unreacted monomer from the polymers. 1H-NMR spectroscopy proved to be an effective method for distinguishing uncyclized methacrylic anhydride units present on the polymers from adsorbed monomer (see Experimental). 

Poly(S-a/f-maleic anhydride)-g-PEO grafts were prepared by reacting monoamine terminated poly(ethylene oxide) with the styrene-maleic anhydride alternating copolymers [70]. The samples were characterized by SEC and UV-VIS and NMR spectroscopy. 

Fourier-Transform Raman Spectroscopy (FTR) was used to characterize a homologous series of aliphatic poly(anhydrides), poly(carboxyphenoxy)al-kanes, and copolymers of carboxyphenoxy propane (CPP) and sebacic acid. All anhydrides show two diagnostic carbonyl bands, the aliphatic polymers has the carbonyl pairing at 1803/1739 cm 1, and the aromatic polymers have the band pair at 1764 and 1712 cm -1. All the homo- and copolymers showed methylene bands due to deformation, stretching, rocking and twisting the spectra for the... 

The sensitivity of vibrational spectroscopy allows interactions of polyelectrolytes and surfactants to be monitored in aqueous and nonaqueous solutions. The solubilization and conformational properties of a comb-shaped copolymer of 1-octadecane-co-maleic anhydride in aqueous solution in the presence and absence of SDS depend on the degree of ionization of the copolymer (2i). The C-H stretching region of the Raman spectrum is sensitive to such interactions. Figure 11 illustrates how the C-H stretching band shifts as a function of solvent (in this case water and heptane). 

Yan et al. [52] explored the use of IPN techniques to produce a composite vinyl-acrylic latex. The first-formed polymer was produced using VAc and divinyl benzene (DVB), while the second formed polymer constituted a BA/DVB copolymer. In both cases the DVB was added at 0.4 wt%. They compared this product with another product, a bidirectional interpenetrating netwodc (BIPN) in which VAc was again polymerized over the first IPN. They noted that the compatibility between the phases was more pronounced in the BIPN than in the IPN as determined using dynamic mechanical measurements and C nuclear magnetic resonance spectroscopy. The concept of polymer miscibility has also been used to produce composite latex particles and thus modify the pafamance properties of VAc latexes. Bott et al. [53] describe a process whereby they bloid VAc/ethylene (VAc/E) copolymers with copolymers of acrylic acid or maleic anhydride and determine windows of miscibility. Apparently an ethyl acrylate or BA copolymer with 10-25 wt% AA is compatible with a VAc/E copolymer of 5-30 wt% ethylene. The information obtained from this woik was then used to form blends of latex polymers by polymerizing suitable mixtures of monomers into preformed VAc/E copolymers. The products are said to be useful for coating adhesives and caulks. 

Whether the concept of charge-transfer complexes in copolymerizations is fully accepted is not certain. Much of the accumulated evidence, to date, such as UV and NMR spectroscopy, does support it in many systems [195]. Further support comes from the strong tendencies to form alternating copolymers over a wide range of feed compositions, and also from high reaction rates at equimolar feed compositions [171]. On the other hand, as shown above, it was claimed in the past that copolymerization of styrene with maleic anhydride involves charge-transfer complexes [171, 181-183]. This, however, is now contradicted in a publication of a study of radical copolymerization of maleic acid with styrene. The reaction was carried out in a dioxane solution at 70 C. The authors reported that UV spectroscopy fails to show presence of a charge transfer and formation of a complex between the two monomers in the copolymerization system [196]. 

Synthesis of block copolymers The A-B-A block copolymers were prepared by reacting the middle block with the N-carboxy anhydride of Y benzyl-L-glutamate, yethyl-L-gluta-mate, c-N-carbobenzyloxy-L-lysine, Y niethyl-L-glutamate, or Y-methyl-D,L-glutamate. The polymerization was carried out in the absence of moisture at room temperature in dioxane-methylene dichloride mixture at 3 % total concentration of amino acid-NCA and the middle block. The polymerization was followed by infrared spectroscopy. After the pol3nneri-zation was terminated, the copolymer was precipitated in methanol for purification and then dried in vacuo. 

Several other propylene-based copolymers and blends have been analyzed by vibrational spectroscopy. The EPDM (ethylene-propylene-diene-monomer) content in PP/EPDM (low temperature impact) blends is a linear function of the ratio A(2850cm" )/A(2920cm" ) up to 80% EPDM. Functionalized PP (compatibilizer) for use in PP blends is often characterized by IR spectroscopy. These compatibilizers typically consist of PP grafted with anhydrides or acids, and may be analyzed in terms of chemical details and graft content. Intermolecular interaction between groups on the grafted side chain and the non-PP component in the blend has been characterized by band shifts and band broadening. 

Fourier-Transform Raman Spectroscopy (FTRS) wus used to characterize an homologous series of aliphatic poly (anhydrides), poly (carboxyphenoxy) alkanes, and copolymers of carboxyphenoxy propane (CPP) and sebacic acid. All anhydrides... 

Polyanhydrides have been characterized with regard to their chemical composition, structure, crystallinity and thermal properties, mechanical properties, thermodynamic properties, and hydrols c stability A representative set of analysis data has been summarized for the polyanhydrides poly(EAD-SA) and poly(CPP-SA) (Table 4). H NMR spectroscopy indicates the degree of randomness that suggests whether the polyanhydrides is either a random or a block copolymer the average length of sequence (Ln) and the frequency of occurrence of specific comonomers sequences (58). The anhydride bond presents characteristic peaks in... 

Polyl(trifluoroethoxy)(octafiuoro pentoxy)]phosphazene decomposes thermally by random chain scission. The decomposition process has been studied in detail for polyKbis trifluoroethoxy) phosphazene] using n.m.r., i.r. spectroscopy, gas chromotography, mass spectrometry, and electron spectroscopy for chemical analysis. Random chain scission is confirmed followed by depolymerization with an average zip length of 35 chain units. The thermo-oxidation of a hydroquinone-phosphorus oxychloride copolymer has also been investigated. Decomposition is a two-stage process, chain scission to form quinone followed by oxidation of the quinone to maleic anhydride. ... 

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