Showing papers in "Journal of Polymer Science Part A in 1971"

Side‐chain crystallinity. I. Heats of fusion and melting transitions on selected homopolymers having long side chains

Abstract: Heats of fusion, melting transitions, and the derived entropies of fusion were obtained by differential scanning calorimetry for examples from three homologous series of homopolymers having long side chains. Homopolymers having side-chain lengths between 12 and 22 carbon atoms were chosen from the poly(n-alkyl acrylates), the poly(N-n-alkyl-acrylamides) and the poly(vinyl esters). The data demonstrated that only the outer paraffinic methylene groups were present in the crystal lattice. This was concluded because phase diagrams obtained for mixtures of structurally different monomers and homopolymers, as well as for selected copolymers, showed only isomorphism in the polymeric examples. In addition, scanning curves, reflecting the distribution of crystallite sizes, became narrower as the side chains became longer. The critical chain length required to maintain a stable nucleus in the bulk homopolymers was a constant value for each homologous series. It varied between 9 to 12 carbon atoms. When heats of fusion were determined in the presence of methanol, main-chain restraints were freed, thus permitting more methylene groups to enter the crystal lattice. Hence, the heats of fusion, the crystallinity, and melting points increased above that of the bulk state. The magnitude of the contribution to the heats of fusion by each methylene group indicated that the hexagonal paraffin crystal modification prevailed in these homopolymers, in agreement with x-ray data from the literature.

Characterization of cellulose acetates by nuclear magnetic resonance

Abstract: An NMR method for determining the distribution of acetyl groups in cellulose acetates was developed. Treatment of cellulose acetates with acetyl-d3 chloride gave products having simple spectra which could be analyzed quantitatively to give the distribution of acetyl groups in the original sample. The method was applied to studying (1) the hydrolysis of cellulose triacetate with ammonia, (2) the acetylation of cellulose acetate with acetyl chloride, and (3) the acetylation of cellulose acetate with acetic anhydride.

Synthesis and characterization of poly‐β‐hydroxybutyrate. I. Synthesis of crystalline DL‐poly‐β‐hydroxybutyrate from DL‐β‐butyrolactone

Abstract: The polymerization of β-butyrolactone was investigated as a possible monomer for a proposed synthesis of the naturally occurring polyester, D-poly-β-hydroxybutyrate (D-PHB). The racemic DL-monomer was used in this initial study to determine the best conditions and catalyst system for use in a subsequent study of the polymerization of optically active β-butyrolactone. In so doing it was found that certain organometallic catalysts (Et2Zn and Et3Al) plus a cocatalyst of water produced highly crystalline samples of polyester from the racemic monomer. This paper describes the synthesis and characterization of the racemic polymer obtained using these catalyst systems, and compares the results obtained with certain other catalysts that were also investigated for this purpose. Examination of the DL-PHB by infrared, NMR, x-ray, and electron microscopy shows that it is possible to synthesize a crystalline racemic polymer that is virtually identical (excepting optical activity) to the naturally occurring polymer, D-PHB.

Permeability of membranes containing ionogenic groups

Abstract: The present paper deals with the transport properties of membranes made of hydrophilic gels containing ionogenic groups. Introduction of ionogenic groups into a gel based on 2-hydroxyethyl methacrylate will affect the permeability of the investigated membranes for sodium chloride by an order or more. Dependences of the permeability on the content of ionogenic groups, three-dimensional network density, and pH were established. The permeability for NaCl was compared for that for bivalent salt (MgSO4). It is shown, on the basis of independently determined distribution coefficients, that an increase in the permeability of ampholytic membranes in comparison with the neutral ones is primarily due to an increase in the diffusivity of the salt in the membranes with modified structure. It can also be concluded that an approximation of the free volume from the volume of the solvent in the membrane cannot be applied to the poly(2-hydroxyethyl methacrylate) gel.

Structure and property relationships in ethylene–vinyl acetate copolymers

Abstract: The effects of vinyl acetate content on crystallinity of ethylene–vinyl acetate (E/VA) copolymers were investigated by x-ray diffraction and differential thermal analysis (DTA). The values of these parameters obtained from DTA were found to agree quantitatively with data calculated from x-ray, probability equations, and copolymer theory. The melting points of the crystalline copolymers, and the molar amounts of vinyl acetate to produce a completely amorphous rubber corresponds exactly to that predicted by the Flory theory. The random character expected in E/VA copolymers is thereby confirmed. The physical properties of E/VA copolymers of all ranges of compositions and crystallinity were determined. Depending directly upon vinyl acetate content, the copolymers changed progressively from highly crystalline polyethylene to semicrystalline polyethylene, a completely amorphous rubber, a soft plastic with a glass transition near room temperature. Properties which were correlated with copolymer composition include: crystallinity, melting point, density, modulus, tensile strength, glass transition, and solubility. Finally, the effect on crystallinity and physical properties of replacing the acetoxy group in E/VA with the smaller, highly polar hydroxyl group (ethylene—vinyl alcohol copolymer) was also investigated.

Thermal degradation of nylon 66

Abstract: The rate of gel formation and color formation in poly(hexamethylene adipamide), nylon 66, is found to be dependent upon the rate of removal of the volatile products of degradation. If a sample of nylon is heated above its melting point in a sealed tube, the material will remain soluble for extended periods of time as the intrinsic viscosity first passes through a maximum, then a minimum, followed by the abrupt formation of insoluble material. The color remains reasonably white. On the other hand, if the volatile material is permitted to escape, rapid gelation and color formation will occur, even in the complete absence of oxygen. Intermediate rates of gelation and color formation can be obtained by control of the rate of volatile material distillation. The decrease in molecular weight evidenced in the sealed tubes is probably due to hydrolysis and ammonolysis of the amide groups which occur simultaneously with the formation of multifunctional crosslinking agents. The volatile material contains an intense absorption in the 290 mμ region. Analysis of the volatile material shows that it contains inter alia, water, carbon dioxide, ammonia, cyclic monomer, hexylamine, hexamethyl-eneimine, hexamethylenediamine, cyclopentanone, 2-cyclopentylcyclopentanone, 2-cyclopentylidinecyclopentanone, and 1,2,3,5,6,7-hexahydrodicyclopenta[b,e]pyridine, which has an intense absorption at 287 mμ, e = 8.87 × 104l./mole-cm, (methanol).

Structure of crystalline polymers with unbranched long side chains

Abstract: The structure and thermodynamic properties of atactic and isotactic acrylic and methacrylic polymers containing 16–18 carbon atoms in the n-aliphatic side chains, and of copolymers of hexadecyl acrylate with isopropyl acrylate were studied by means of x-ray and differential thermal analysis. The crystallization of branched acrylic and methacrylic polymers and of acrylic copolymers proceeds in the form of a hexagonal crystal, regardless of the configuration of the backbone chain. Methods of ordering branched macromolecules are proposed, and the melting points, heats and entropies of fusion determined. The role of flexibility of the backbone chains in ordering and the crystallization processes was determined. In the case of poly(n-alkyl acrylates) the backbone chain is involved in the crystalline lattice; this is not the case in methacrylates and copolymers of hexadecyl acrylate with isopropyl acrylate. Some similarity was assumed between the structure of biopolymers and synthetic branched polymers.

Effect of pH on the reactivity ratios in the copolymerization of acrylic acid and acrylamide

Abstract: The content of acrylic acid and acrylamide in their copolymers can be controlled by changing pH. The reactivity ratio of acrylic acid decreases with increasing pH, while the reactivity ratio of acrylamide increases with increasing pH. At low pH values, acrylamide is present in its protonated form which causes its reactivity to be low whereas at high pH values the reactivity of acrylic acid is decreased owing to its dissociation. When the monomer and radical approach each other, the acrylate anion becomes the least reactive species because of its symmetrical charge distribution, like charge repulsion and barium ion screening effect. HMO calculations were performed for models of all monomers and polymer radicals involved in copolymerizations. The experimental results concerning the reactivity of acrylic acid and acrylamide in copolymerization and the observed reactivity ratios were discussed on the basis of HMO calculations and resonance and Coulomb electrostatic effects. The observed reactivity ratios were correlated with the calculated differences in resonance energies computed for the models of transition states involved in copolymerizations.

Constitutive equations for elastomers

Abstract: General relations were derived by expanding the strain-energy density function in terms of the invariants of the deformation tensor. Some constitutive equations obtained by keeping a third term in the expanson in addition to the two terms retained in the Mooney-Rivlin equation were tested in the light of currently available experimental data. It is shown that by the retention of the third term the upswing in the Mooney stress at low values of γ−1 is successfully predicted, and the stress—strain behavior can be described with excellent accuracy up to break, even in carbon black-filled rubber which is difficult to describe by the Mooney-Rivlin equation.

Mechanism of propagation and degenerate chain branching in the oxidation of polypropylene and polyethylene

Abstract: Samples of polypropylene with adjacent and isolated hydroperoxide groups have been prepared. The rate constants of free-radical formation from solid hydroperoxides were measured by the inhibitor method. It was found that the free radicals yielded by adjacent hydroperoxide groups are formed more rapidly. The main reaction of free-radical formation in oxidized polypropylene is of the type: ROOH + ROOH → RO + H2O + RO2˙. The average yield of free radicals from polypropylene hydroperoxide is 2–4%. Oxygen has no effect on the yield of free radicals. However, the pressure of oxygen Po2 affects the rate of degenerate chain branching in polypropylene. The number of adjacent hydroperoxide groups and the rate of initiation increase with Po2. Consequently, a reaction of the type, R˙, + RH → RH + R˙, plays an important part in transport of free valence through solid polymer. This reaction is very fast in polyethylene, and no adjacent hydroperoxide groups are formed. The free radicals from polyethylene hydroperoxide are found to form by a reaction of the type: ROOH → RO˙ + HO˙.

α–γ transition in nylon 6

Abstract: The α to γ transition that occurs in nylon 6 upon iodine treatment was investigated by infrared spectroscopy, differential thermal analysis, and x-ray diffraction techniques. Thin films of nylon (0.2 mil) were treated in either iodine–potassium iodide aqueous solution or in iodine vapor. Very short treatment times, in the order of 30 sec, were found to effect the transition when a solution 0.5M with respect to iodine was used. The infrared spectra of the iodine nylon complexes formed from either the α- or γ-nylon 6 treated in vapor or dissolved iodine were all similar. This is an indication that molecular iodine is the active species in forming the complex. The temperature of the washing solution used to remove the iodine from the nylon determines whether an α-nylon 6 or γ-nylon 6 is obtained from the complex after washing. Nylon 6 plaque surfaces and thin films are similar in their behavior towards the iodine treatment. The γ-nylon 6 is a stable modification at all temperatures below its melting point. The conversion of the γ form back to the α modification can occur only if the hydrogen bonding is severely affected, e.g., by phenol treatment, iodine treatment, melting, etc. Infrared spectroscopy provided no evidence for an α–γ transition in nylon 6 on heating the sample continuously through its melting point. The shapes of the melting peaks in the above two modifications of nylon 6 were sufficiently different to provide a means of identifying the two crystalline forms.

Effects of complexing agents in radical copolymerization

Abstract: Radical copolymerization of methyl methacrylate (MMA, M1) with various monomers has been studied in presence of modifiers, i.e., complexing agents (CA): ZnCl2, AlCl3, AlBr3, Al(C2H5)2Cl, forming coordinate complexes with ester group of the monomer and of the propagating radical. The comonomers of the first group form complexes of similar structure and stability as MMA, methyl acrylate, or butyl acrylate. The comonomers of the second group do not form complexes with the modifiers (vinylidene chloride, 2,6-dichlorostyrene, p-chlorostyrene, styrene). For all systems studied the copolymer composition follows the Mayo-Lewis equation. In the first group of the systems the effective reactivity ratios (r1, r2) approach unity with increase of the CA molar content (r1 = r2 ≃ 1 at [(CA)/MMA] + [MA] ≥ 0,3) In the second group of the systems the values of r1 either increase to a limit value (at [CA]/[MMA] ≥ 0.3), pass through maximum, or decrease to a limiting value with the CA molar content. The values of r2 decrease in all systems. The character of variation of r1 and r2 has been explained in terms of effects of the CA's on reactivity of MMA and PMMA radical. The equations for the copolymer compositions in these systems have been derived.

Polyimides based on pyrazinetetracarboxylic dianhydride and some related model compounds

Abstract: A study was made of polyimides based on pyrazinetetracarboxylic dianhydride (PTDA) plus heterocyclic diamines different from the one previously reported by Hirsch. It was postulated that thermal properties might be improved if the diamine portion did not contain the N–N linkage. The results indicate that these heterocyclic-based polyimides are in fact of lower thermal stability and of less molecular weight buildup than their corresponding polypyromellitimides. Thermal failure, outlined by their TGA curves, is shown not to be due to an inherent lack of stability for such polymers, but rather, to synthesis problems arising from both the anhydride and amine precursors. The synthetic problems are twofold: (1) the heterocyclic diamines used in this study display low reactivity; (2) pyrazinecarboxylic acids readily decarboxylate. These conclusions were drawn from a correlation of the relative basicity values of the diamines of consideration and from study of a series of model compounds prepared from an appropriate amine or diamine with PDTA, pyrazinedicarboxylic anhydride, phthalic anhydride, or pyromellitic dianhydride. An accumulation of infrared and mass spectra data for these models relate that the proposed pyrazine polyimides are not of complete polyimide structure, but rather resemble recurring amide-imide units.

Thermal degradation of poly(alkyl acrylates). II. Primary esters: Ethyl, n-propyl, n-butyl, and 2-ethylhexyl

Abstract: Quantitative analyses of the products of thermal degradation of poly(ethyl acrylate), poly(n-propyl acrylate), poly(n-butyl acrylate) and poly(2-ethylhexyl acrylate) have been made, principally by the combined application of GLC and mass and infrared spectroscopy. Data are recorded in mass balance tables. The major gaseous products are carbon dioxide and the olefin corresponding to the ester group. The minor gaseous products include the corresponding alkane, the alkane/olefin ratio being of the order of 10−2–10−3, and traces of carbon monoxide and hydrogen. The alcohol corresponding to the alkyl group is the major liquid product but there are also traces of monomer and the corresponding methacrylate. Alcohol production exhibits autocatalytic properties. The chain fragment fractions of the products are colored yellow and have average chain lengths of 3.2, 3.3, 3.6, and 5.6 for the ethyl, n-propyl, n-butyl and 2-ethylhexyl esters, respectively. The infrared spectra are similar to those of the parent polymers but with well defined differences. Insolubility develops in the ethyl, n-propyl, and n-butyl esters, but the residual material from poly(2-ethylhexyl acrylate) remains soluble even at very advanced stages of degradation. All of these products and reaction characteristics are accounted for in terms of radical reactions with a unique initiation step.

Thermal degradation of poly(alkyl acrylates). I. Preliminary investigations

Abstract: A qualitative survey of the thermal degradation reactions which occur in poly(ethyl acrylate), poly(n-propyl acrylate), poly(isopropyl acrylate), poly(n-butyl acrylate) and poly(2-ethylhexyl acrylate) has been made by using three thermal analytical methods: thermogravimetric analysis (TGA), thermal volatilization analysis (TVA), and the dynamic molecular still (DMS), all combined with infrared and mass spectrometry. Degradation in poly(isopropyl acrylate), which is a secondary ester, becomes discernible at 260°C and proceeds in two stages. The other four polymers, which are all primary esters, are more stable. They degrade in a single-stage process starting at 300°C. The principal volatile products from the primary esters are carbon dioxide and the olefin and alcohol corresponding to the alkyl group. A roughly equivalent quantity of short-chain fragments is also formed. From poly(isopropyl acrylate), carbon dioxide and propylene are the only volatile products in the first phase of the reaction.

Side‐chain crystallinity. III. Influence of side‐chain crystallinity on the glass transition temperatures of selected copolymers incorporating n‐octadecyl acrylate or vinyl stearate

Abstract: The influence of side-chain crystallinity on the glass transition temperatures of selected copolymers was investigated. The copolymers were selected, in part, from those whose crystallinity was treated in the preceding paper. These included the lower amorphous acrylate esters, such as methyl, ethyl, n-butyl, and 2-ethylhexyl acrylates, together with methyl methacrylate and acrylonitrile, each copolymerized with n-octadecyl acrylate over the range of composition. The decline in the glass transition temperature was linear with increasing weight fraction of n-octadecyl acrylate for all systems in the composition range where the copolymers were essentially amorphous. The extrapolated Tg for the amorphous state of poly(n-octadecyl acrylate), and for amorphous poly(oleyl acrylate), was close to −111°C. This coincided with a value previously obtained by an extrapolation of data on homologs. Beyond a critical fraction of octadecyl acrylate (0.3 to 0.5), developing side-chain crystallinity in n-octadecyl acrylate raised the glass temperature steadily for all systems, up to a value of 17-C, obtained for the crystalline homopolymer. Crystallinity did not develop in stiff copolymers until Tg was about 30°C below the melting point of the most perfect crystals. In compositionally heterogeneous copolymers incorporating vinyl stearate, blocks of crystalline units appeared to be dispersed in a glassy matrix of amorphous co-units. An empirical equation was derived which fitted the experimental data for random copolymers, over all composition ranges, with fair accuracy.

Influence of free and copolymerized triplet quenchers on the photolysis of poly(vinyl phenyl ketone) in solution

Abstract: The influence of free, diffusion-control quenchers of triplets (naphthalene, biphenyl, 2,5-dimethyl-2,4-hexadiene) on the photolysis of poly(vinyl phenyl ketone) in benzene solution has been investigated. The Stern-Volmer plots for quenching of main-chain scission were linear, and the quenching constants were independent of the macroviscosity of the solutions. Copolymers of vinyl phenyl ketone with 1-vinylnaphthalene and 2-vinylnaphthalene containing as much as 10% (by weight) vinylnaphthalene were prepared. The photolysis of the copolymers was compared with the photolysis of poly(vinyl phenyl ketone) in the presence of free naphthalene. It was found that the quenching efficiency of found naphthalene units was about 21 times higher. The possibility of migration of the absorbed energy along the polymer chain is discussed. The relation between average-number molecular weight Mn and intrinsic viscosity [η] has been determined osmometrically. For unfractionated poly(vinyl phenyl ketone) in benzene at 30°C, the relation [η] = 2.82 × 10−5Mn0.84 has been found.

Synthesis and characterization of poly‐β‐hydroxybutyrate. II. Synthesis of D‐poly‐β‐hydroxybutyrate and the mechanism of ring‐opening polymerization of β‐butyrolactone

Abstract: Synthesis of the naturally occurring polyester, D-poly-β-hydroxybutyrate (PHB) was accomplished by using an optically active monomer. Polymerization of D-(+)-β-butyrolactone (β-BL) of 73% optical purity with a catalyst system of Et3Al–H2O produced a polymer with a similar optical activity and essentially identical to the natural polymer as isolated from bacterial cells. This paper describes the synthesis and characterization of this optically active polyester along with a suggested mechanism to account for the observed stereospecific polymerization of β-BL with this catalyst system.

Titration curves of p‐aminobenzoic acid–formaldehyde polymer in relation to its structure

Abstract: p-Aminobenzoic acid and formaldehyde were condensed in the presence of acid catalyst. The linear condensation polymer thus obtained was then separated into four fractions by a fractional precipitation method. Conductometric titrations were carried out on these four polymer fractions and the conglomerate in nonaqueous solvents with acid as well as base. The titration curves indicated a large number of additional breaks before the complete neutralization of COOH or NH2 groups. These observations have been interpreted in terms of degree of polymerization and the structure of the polymer.

Concentration effects in gel‐permeation chromatography

Abstract: Peak elution volume in gel-permeation analysis of polymers depends on sample concentration as well as molecular weight. Elution volume is related to the logarithm of the hydrodynamic volume of the solvated polymer species. The hydrodynamic volume of a given species is, in turn, inversely related to the concentration. Since molecular weight and concentration are interacting variables, the elution volume–molecular weight relation is not uniquely determined. A model is presented which accounts quantitatively for concentration effects, using parameters which are available a priori. The data required are polymer molecular weight, concentration, and density and the Mark-Houwink relation for the particular polymer-solvent combination.

Polysulfone–polydimethylsiloxane block copolymers

Abstract: Alternating block copolymers have been synthesized from dihydroxyl-terminated polysulfone and bis(dimethylamine)-terminated polydimethylsiloxane oligomers. The products are soluble, amorphous, and transparent, and display excellent thermal and hydrolytic stability. Elastomeric and rigid compositions can be prepared by varying oligomer molecular weight. Copolymers made with oligomers of ≥ 5000 molecular weight are two-microphase systems which display glass transition temperatures at −120°C and at +160°C, and therefore have a wide useful temperature range.

Kinetic aspects of catalyzed reactions in the formation of poly(ethylene terephthalate)

Abstract: The influence of different types of catalysts on the polycondensation reaction has been studied in a model system. It has been found that two kinds of catalysts are to be distinguished. “Transesterification” catalysts (Mn, Pb, Zn) are very active in media having both a high and a low hydroxyl content. However, they are easily poisoned by very small amounts of carboxylic endgroups. This restricts their activity to the period of transesterification. The “polycondensation” catalyst antimony is insensitive to the presence of acidic endgroups. However, its activity is inversely proportional to the hydroxyl group concentration For this reason antimony is hardly effective during transesterification. During polycondensation it becomes gradually more active.

Free‐radical homopolymerization and copolymerization of vinylferrocene

Abstract: The benzene solution homopolymerization of vinylferrocene, initiated by azobisisobutyronitrile, gave a series of benzene-soluble homopolymers. Thus, free-radical copolymerization studies were performed with styrene, methyl acrylate, methyl methacrylate, acrylonitrile, vinyl acetate, and isoprene in benzene. With the exception of vinyl acetate and isoprene, which did not give copolymers with vinylferrocene under these conditions, smooth production of copolymers occurred. The relative reactivity ratios, r1 and r2, were obtained for vinylferrocene–styrene copolymerizations by using the curve-fitting method for the differential form of the copolymer equation, by the Fineman-Ross technique, and by computer fitting of the integrated form of the copolymer equations applied to higher conversion copolymerizations. In styrene (M2) copolymerizations, the curve-fitting and Fineman-Ross methods both gave r1 = 0.08, r2 = 2.50, while the integration method gave r1 = 0.097, r2 = 2.91. Application of the integration method to methyl acrylate and methyl methacrylate (M2) gave values of r1 = 0.82, r2 = 0.63; r1 = 0.52, r2 = 1.22, respectively. The curve-fitting method gave r1 = 0.15, r2 = 0.16 for acrylonitrile (M2) copolymerizations. From styrene copolymerizations, vinylferrocene exhibited values of Q = 0.145 and e = 0.47.

Transparent ultraviolet‐barrier coatings

Abstract: A number of phenyl polyesters have been synthesized to furnish molecules whose backbones rearrange under ultraviolet irradiation to an o-hydroxybenzophenone structure. This photochemical Fries rearrangement produces ultraviolet opacity in the irradiated film while maintaining visual transparency. Thin coatings of these polyesters completely protect substrates ordinarily sensitive to ultraviolet light. Spectroscopic analysis of various rearranged films and coatings clearly shows that the o-hydroxybenzophenone polymer formed is concentrated at the irradiated surface of the original polyester coating as a “skin”. Such a skin, formed in situ during the irradiation, functions to protect both the original polyester coating as well as the coated substrate from degradation by ultraviolet irradiation. Furthermore, a significant “healing” mechanism appears inherent in these coatings, for as the exposed skin ultimately degrades under extended ultraviolet irradiation, more of the underlying polyester layer apparently rearranges to compensate for the loss. Thus the clear coating functions both as a protective skin and a rearrangeable reservoir. Modified structures of the polyesters have been prepared which possess, in addition to their protective film properties, a useful solubility spectrum and a good solution shelf life.

Photochemical and thermal isomerization in polymer matrices: Azo compounds in polystyrene

Abstract: Photochemical and thermal geometrical isomerizations of monoazo compounds have been studied in polystyrene–n-butylbenzene compositions. Cis–trans isomer ratios established by light absorption were found to depend on matrix viscosity. Where the compositions were above their respective glass temperatures, all thermal isomerizations conformed to first-order kinetics. Where compositions were below their respective glass temperatures, the initial isomerization rates were abnormally fast, decaying to normal first-order processes after substantial amounts of reaction had taken place. These effects have been interpreted in terms of the vitreous properties of polystyrene.

Preparation and properties of some water‐soluble cobalt (III)–poly‐4‐vinylpyridine complexes

Abstract: Water-soluble cobalt(III) chelates having a polymeric ligand such as cis-[Co(en)2-PVPCl]Cl2 and cis-[Co-(trien)PVPCl]Cl2 (PVP = poly-4-vinylpyridine) were prepared by substitution reactions between cobalt(III) chelate and PVP in water–alcohol solution. PVP of different degrees of polymerization was used as the ligand in preparation of these complexes. The PVP complexes were identified and their properties ascertained by microanalysis and by a study of the infrared, ultraviolet, visible, and PMR spectra. Most of the characteristic properties of these complexes may be ascribed to the polymeric structure of the PVP ligand.