Allylic polymers from resin acids

An unsaturated adduct has been synthesized by the Diels-Alder reaction between resin acids and diallyl maleate. The obtained polymerizable product can be used both as monomer in the formation of allyl polymers and crosslinking agent. The monomer and its polymers were investigated by usual physical and chemical methods. The synthesized polymers present a linear structure, possibly associated with intramolecular cyclization at low molecular weights, or a three-dimensional structure at high conversions. They are fairly thermostable substances with carboxylic groups in the polymer chain.     

Allylic polymers. Diallyl 2-substituted succinate prepolymers and their properties

Diallyl 2-substituted succinates, obtainable via the addition of alkenes or alkylaromatics to maleic anhydride, undergo intramolecular cyclization during polymerization to low molecular weight prepolymers. The amount of this cyclization and the properties of the cured prepolymers are profoundly affected by the structure of these 2-substituents. Thus, the degree of cyclization decreases with these substituents in the order: aralkyl and isobutyl > unhindered alkenyl > alkyl > hindered alkenyl. Properties of thermosetting molding compounds based on these prepolymers are inferior to those of poly-(diallyl phthalate) molding compounds.     

Copolyamides derived from brassylic acid

Polyamides were prepared from C₆ to C₁₂ diamines with brassylic acid, a linear C₁₃ dicarboxylic acid, derived from Crambe seed oil. One distinct characteristic of these polymers is their low moisture adsorption as compared to nylon 66 and nylon 6. To modify the properties of these nylons, multi-component copolyamides were prepared from hexamethylene diamine and mixtures of brassylic acid with adipic, terephthalic, or isophthalic acids. It was found that the melting points of the co-polyamides were changed by the choice and the levels of the diacids used. The melting point-composition curves all show a eutectic minimum. The glass transition temperature of nylon 6,13 is also changed by the incorporation of other diacids. Water adsorption of nylon 6,13 increases with increased substitution of brassylic acid by other diacids in the order of adipic > isophthalic ≥ terephthalic. Mechanical properties of some copolyamides are in the same range as the commercial nylon 11 and nylon 12. The low moisture absorption, reduced fabrication temperature, and the wide range of properties obtainable through copolymerization make copolyamides derived from brassylic acid potentially suitable as specialty tubing, powder coatings, and molded machine parts. They will be commercially viable when brassylic acid becomes available on a large scale and is competitively priced.     

Allylic esters of polymeric fat acids

Summary 1. Allyl, β-methallyl, and β-chlorallyl esters have been prepared from polymeric soybean fat acids by direct esterification and from dilinoleic acid by transesterification of methyl dilinoleate. 2. The method of polymerizing the esters and the properties of the polymers are described. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Allylic polymers from resin acids. Monomer synthesis at high temperature

New chemical compounds, i. e. ketones of the abietic acid-diallyl maleate Diels-Alder adduct, have been synthesized when the reaction of abietic acid and diallyl maleate was carried out at high temperatures (up to 250°C). Having unsaturated groups in their structure, they are polymerizable substances. The monomers and the polymers have been investigated by commonly used chemical and physical methods. The polymers are soluble in polar organic solvents only at low molecular weights. The behavior of these compounds as crosslinking monomers in copolymer systems has been examined.     

Preparation and evaluation of surface-active brassylic acid-ethylene oxide adducts

Both liquid and solid surface-active adducts of brassylic (tridecanedioic) acid were prepared by potassium hydroxide-catalyzed addition of ethylene oxide gas to the molten acid. The number-average molecular weights \(\left( {\overline {MW} _n } \right)\) of the adducts ranged from 500 to 3,000. These adducts cover a wide span in the ratios of hydrophilic to lipophilic portions of the molecule. They are unique in that hydrophilic end-groups sandwich a rather long chain of lipophilic methylene units. Treatment of some adducts with hot, saturated, aqueous sodium chloride induced transesterification and produced hydroxyl-terminated, multi-brassylic, poly(ethylene glycol) esters of MW_n 1,000 to 4,000, all of which were efficient surface-active agents. Average degrees of polymerization of the poly(ethylene oxide) (PEO) chains were determined by a) functional group analysis, b) weight increase, and c) methanolysis of the products, followed by gas-chromatographic analysis of the isolated poly(ethylene glycol) fraction. Surface tension, critical micelle concentration, emulsion stability, and efficiency as an emulsifying agent in the aqueous polymerization of vinyl acetate were measured to evaluate surfactant properties of products in which the degrees of polymerization of the PEO chains ranged from 1.4 to 44.     

Practical Synthesis of Allylic Silanes from Allylic Esters and Carbamates by Stereoselective Copper‐Catalyzed Allylic Substitution Reactions

The first copper‐catalyzed allylic substitution reactions of allylic acetates and carbamates employing a bis(triorganosilyl)zinc reagent are reported. This novel procedure avoids the use of stoichiometric amounts of copper salts which are usually mandatory with this chemistry. Application of this methodology to standard model substrates substantiates a high diastereoselectivity for the double bond geometry (E : Z) as well as the relative configuration (syn : anti).     

Thermal behavior and reactivities of prepolymers prepared from aromatic biscyanamides and bismaleimide

Novel polymers obtained by reaction of aromatic biscyanamide and bismaleimide compounds were investigated. By heating 4,4′-methylene bis(o-methylphenylcyanamide) (BMCA) with 4,4′-methylene bis (phenylmaleimide) (BMI) at 120°C in N,N-dimethylformamide (DMF), prepolymers were obtained by the conversion of cyanamide to cyanoguanidine and the addition of an imino group on the double bond of maleimide. The prepolymer showed suitable behavior for thermosetting resin used in molding, i.e., it melted temporarily and then polymerized in an isochronal heating process (5°C/min). On heating above 170°C, the prepolymer could polymerize with ring formation of melamine and isomelamine. The cured product had good heat-resistant properties.     

Preparation of prepolymers from diglycidylether of bisphenol A containing imide groups

Epoxy resins derived from Bisphenol A have been modified with new diphenols containing imide moieties in order to improve their thermal properties. The diphenols have been synthesized from dianhydrides and aminophenols by condensation reactions. Diphenols as well as modified resins have been characterized by IR and NMR spectroscopy. The thermal characteristics were evaluated by DSC and TGA.     

Synthesis and characterization of isocyanate-terminated polyurethane prepolymers

Using statistically designed experiments, seven variables were investigated to determine their effect on the physical and mechanical properties of isocyanate-terminated polyurethane prepolymers. The choice of catalyst (dibutyltin diacetate, T-1, or stannous octoate, T-9) along with the ratio of diol to triol were found to most significantly control the prepolymer properties. Other variables such as reaction temperature, reaction time, and order of polyol addition did not affect the system. In comparing the two catalysts, T-9 was found to be concentration sensitive, yielding low-viscosity prepolymers at the lower catalyst level and higher viscosity, unstable materials at the higher catalyst level. No evidence was found to show concentration sensitivity of T-1. A series of prepolymers based on varying ratios of diol to triol were synthesized, and their physical and mechanical properties are reported.     

Adsorption of dimer,trimer, stearic,oleic, linoleic,nonanoic and azelaic acids on ferric oxide

The adsorption isotherms of solutions of dimer, trimer, stearic, oleic, linoleic, nonanoic and azelaic acids in organic solvents, (mostly hexane) have been determined on an alpha ferric oxide with a surface area (B.E.T. N₂ adsorption) of 99 m² (99 × 10²⁰ A²) per gram. They all showed limiting adsorption as grams adsorbed per gram of iron oxide beyond a concentration of about 1 g/100 cc, analagous to the Langmuir type monolayer isotherm. Areas per molecule were calculated and compared with areas of close-packed models in positions parallel to and perpendicular to the surface. The calculated areas corresponded more closely to the flat or parallel positions. Heats of adsorption were determined and were in the range of 27–71 kcal/eq, suggesting chemisorption of the COOH group at the surface. The value of dimer acid suggests that both COOH groups are chemisorbed. Models show that the parallel position permits both COOH groups to touch the surface. The perpendicular position generally does not permit both COOH groups to touch the surface. Dimer acid showed a value (71 kcal/eq) higher than the monobasic acids (44–55 kcal/eq), possibly due to interaction of the ring structure (partly aromatic) with the surface. Azelaic acid from an 80–20t-butanol-hexane solvent showed a lower value of 27 kcal/eq, possibly due to adsorption of a hydrogenbonded alcohol-acid moiety as such. Journal Series No. 547, General Mills, Inc. Research Laboratories.     

Melamine/epichlorohydrin prepolymers: syntheses and characterization

The basic catalysis of melamine with epichlorohydrin gives prepolymers that can be used in the preparation of energetic materials. In this work, sodium hydroxide and triethylamine were used as catalysts and ethyleneglycol as initiator. Different reaction conditions were tested and the characterization of the products was carried out by IR and NMR spectroscopy and MS spectrometry, hydroxyl groups content, vapour pressure osmometry and elemental and thermal analysis. Epichlorohydrin reacts with the amine groups of melamine and forms lateral chains with hydroxyl and epoxide end groups, which can be used for curing purposes. The two catalysts lead to similar products, confirmed both by the structure and number of the lateral chains. The melamine/epichlorohydrin ratio was found important for the structure of the final compounds. Chlorine atoms leave the molecules during reaction due to basic catalysis. In the light of the use of the prepolymers in energetic materials, the presence of the 1,3,5-s-triazine ring and the lateral chains with end groups curable by e.g. isocyanates was accomplished with success. However, the loss of chlorine atoms limits to a certain extent their possible substitution by energetic groups.     

Catalytic Asymmetric Synthesis of Branched Chiral Allylic Phenyl Ethers from (E)‐Allylic Alcohols

The first di‐μ‐amidate dipalladium complexes and a new di‐μ‐carboxylate dipalladium complex of the COP (cobalt oxazoline palladacycle) palladium(II) catalyst family are reported and characterized crystallographically. The di‐μ‐amidate complex 3 and its enantiomer (ent‐ 3 ) are the first asymmetric catalysts that allow commercially available, or readily accessible, (E)‐2‐alken‐1‐ols to be transformed to enantioenriched branched allylic aryl ethers upon reaction of their trichloroacetimidate derivatives with phenols. The 3‐aryloxy‐1‐alkene products are formed in high enantiomeric purity (typically 90–98% ee) and useful yields (61–88%).     

Cast and mold polymerization of organic glass by irradiation from fluid and soft gel prepolymers

Casting and mold polymerization processes were investigated by means of γ-irradiation of methyl methacrylate prepolymer systems containing some quantity of polyfunctional monomers. Some physical properties, such as supercooling tendency and temperature dependence of viscosity and relaxation time in fluid prepolymers, were measured and related to cast polymerization at low temperatures. It was found that free-state casting with no frame or mold was possible using viscous states of prepolymer in the supercooled state. Furthermore, efficient mold polymerization using soft gel prepolymer was studied. That is, plastic soft gel prepolymer was prepared conveniently by irradiation of fluid prepolymer, then molded into spherical or nonspherical curved surface shapes, and curved by reirradiation. Polymerization and gelation behavior of soft gel prepolymer and penetration degree of prepolymer as a measure of plasticity of gel were studied in relation to prepolymer composition and irradiation condition.     

Gas transport properties of polybenzoxazinoneimides and their prepolymers

Three types of imide-containing polyamic acids (polybenzoxazinoneimide prepolymers), namely, a homopolymer, a copolymer, and a polymer-metal complex were synthesized and used for homogeneous membranes preparation. These membranes exhibited good physico-mechanical properties and also chemical and hydrolytical stability. Their gas separation properties were measured and analyzed by correlation with macromolecular packing density. Polybenzoxazinoneimide membranes were prepared by heating prepolymer membranes to 220 °C. Difference between gas separation properties of membranes based on polybenzoxazinoneimides and those of their prepolymers was estimated. Gas transport properties of all novel membranes were compared with those of known membranes by using Robeson's diagram. It was established that a polybenzoxazinoneimide membrane including a polymer-metal complex is the most effective among membranes studied here.     

1H nuclear magnetic resonance study of polyurethane prepolymers from toluene diisocyanate and polypropylene glycol

Polyurethane prepolymers prepared from toluene 2,4‐diisocyanate, toluene 2,6‐diisocyanate, and polypropylene glycol with a ratio between the isocyanate and hydroxyl groups equal to 2 were analyzed by ¹H nuclear magnetic resonance (NMR) spectroscopy in acetone‐d₆. Different temperatures and concentrations were used. Toluene 2,4‐dimethylurethane and toluene 2,6‐dimethylurethane were synthesized and used as model compounds to assign prepolymers signals. Measurements of spin–lattice relaxation time T₁ by “inversion recovery” experiments were carried out on toluene 2,4‐diisocyanate, toluene 2,6‐diisocyanate, toluene 2,4‐dimethylurethane, toluene 2,6‐dimethylurethane, and polyurethane prepolymers. Differences in T₁ times were used to interpret prepolymers spectra, by means of the strong observed effect on protons due to the presence of adjacent isocyanate groups. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 347–357, 2003     

Preparation and characterization of bismaleimide-diamine prepolymers and their thermal-curing behavior

Various bismaleimide-diamine Michael addition type prepolymers were prepared through melt condensation and using acetone, dimethylformamide, and m-cresol as solvents in a molar ratio of 1 : 1. Structures of the prepolymers, such as terminal moieties and molecular weight of main chain, depended strongly on the preparation conditions used. More terminal double bonds were observed in the molecule of the prepolymer (sample 3) prepared in dimethylformamide solution without a catalyst. In contrast, the prepolymer produced in m-cresol solution had a polyaspartimide structure with a higher molecular weight. The differential scanning calorimetry and Fourier transform infrared spectra results demonstrated that the molecular structure of the prepolymer had a noticeable effect on their thermal-curing behavior. Thermal properties (T_g and T_d) of cured polymers were evaluated. The polyimide (sample 3b) from sample 3 exhibited the highest T_g and but still retained very good processing properties for film casting. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2471–2477, 1998     

Synthesis of azelaic acid and suberic acid fromVernonia galamensis oil

We have demonstrated the potential ofVernonia galamensis seed oil as a source of dibasic acids. Reaction of nitric acid withV. galamensis oil afforded a homologous series of dibasic acids that include butanedioic acid, pentanedioic acid, hexanedioic acid (adipic), heptanedioic acid (pimelic), octanedioic acid (suberic), nonanedioic acid (azelaic), decanedioic acid (sebacic), and undecanedioic acid. Using a combination of chloroform extraction and subsequent water crystallizations, we have isolated suberic acid (∼95% purity by GC) and azelaic acid (∼95% purity by GC). The isolated yield of suberic acid is 15% and of azelaic acid is 11%. Reported reaction of nitric acid with ricinoleic acid (from castor oil) gave 8.8% suberic acid and 7.2% of a mixture of suberic and azelaic acids.     

13C-NMR analysis of phenol-urea-formaldehyde prepolymers and phenol-urea-formaldehyde-tannin adhesives

Phenol-urea-formaldehyde-tannin (PUFT) adhesives were prepared by co-polymerization of Pinus pinaster bark tannins with phenol-urea-formaldehyde (PUF) prepolymers at room temperature. A detailed analysis by ¹³C-NMR spectroscopy of the resins together with an evaluation of their properties was performed in order to find suitable preparation conditions for prepolymers prior to their co-polymerization with tannins. ¹³C-NMR spectroscopy allowed identification of the different linkages formed and quantification of the main functional groups in the PUF prepolymers, which were greatly influenced by the preparation conditions. The decrease in the free formaldehyde content in the PUFT adhesives with respect to the original prepolymers was attributed to tannin methylolation at room temperature. The fast increase in the apparent viscosity of the PUFT adhesives after the blending suggested the possibility of a co-polymerization reaction between tannins and the PUF prepolymers; however, the occurrence of this reaction could not be confirmed by ¹³C-NMR.