Synthesis and polymerization of unsaturated derivatives of halogenated phenols

Summary The preparation of p-styrenesulfonic and methacrylic acid esters of the microbiocides 2, 4, 6-trichlorophenol and 4-chloro-m-cresol, and their characterization by IR, ¹H and ¹³C NMR spectroscopy are described. The radical homopolymerization of the biocidal monomers, and their copolymerization with various vinyl monomers have been studied. The polymerization gives polymers in which the microbiocide moieties are covalently attached to the polymer backbone chain by ester links.     

New unsaturated derivatives of Xanthan gum: Synthesis and characterization

Unsaturated Xanthan derivatives, which can be used for the development of biodegradable three-dimensional networks having hydrogel properties, were prepared by esterification under various conditions. Xanthan gum derivatives with different degrees of substitution were obtained by reaction with an unsaturated organic acid (acrylic acid) or with acid reactive derivatives (acryloyl chloride, maleic anhydride). The presence of acrylate and maleate groups in the modified structure of Xanthan gum was detected by ATR-FTIR, ¹H liquid NMR and ¹H HRMAS NMR spectroscopies. The degree of substitution as determined by ¹H NMR could be controlled by varying the chemical nature of functionalisation agent, reaction time and temperature.The results proved that this polysaccharide can be modified by esterification with acids or unsaturated acid derivatives for further synthesis of hydrogels. Maleic anhydride presents a higher reactivity as compared to acrylic acid and acryloyl chloride.     

Synthesis and polymerization of new vinyl derivatives of thymine

N-acryloyl and N-methacryloyl derivatives of thymine were prepared by one-step reaction of silylated thymine with acryloyl chloride and methacryloyl chloride, respectively, in good yields. These vinyl monomers containing thymines were polymerized and copolymerized with water soluble vinyl monomers such as acrylamide and vinylpyrrolidone by free-radical polymerization. Complex formation between copolymers and RNA in aqueous solution was studied by means of UV spectroscopy.     

On the polymerization of acrylonitrile in the presence of some unsaturated triazine derivatives

The polymerization of acrylonitrile in the presence of some unsaturated, triazinebased fluorescent brighteners (FB) has been investigated. It was found colourimetrically that more than 80% of the FB is incorporated in the polymer. The initial concentration of 0.1 wt.-% is sufficient to obtain a good bleaching effect without significant decrease of the molecular weight.     

Synthesis and polymerization of the acrylamide derivatives of fatty compounds

The Ritter reaction of plant oil triglycerides (such as soybean and sunflower oil) with acrylonitrile was used to introduce acrylamide functionality on the triglyceride. Acrylonitrile and triglycerides were reacted in the presence of H₂SO₄, and acrylamide derivatives were obtained in yields of 45 and 50% for sunflower oil and soybean oil, respectively. Radical initiated copolymerization of the acrylamide derivatives of the triglycerides with styrene produced semirigid polymers. Characterization of new monomers and polymers was done by ¹H‐NMR, ¹³C‐NMR, IR, and MS. The swelling behavior of the crosslinked network polymers was determined in different solvents. Glass transiton temperature (T_g) of the cured resin was also determined by differential scanning calorimeter to be 40°C for soybean based polymer and 30°C for sunflower‐based polymer. Homo‐ and copolymerization behavior of acrylamide derivatives of methyl oleate (MOA) and methyl 10‐undecenoate (MUA) were also investigated. The reactivity ratios of these monomers with respect to styrene were determined by the Fineman–Ross method using ¹H‐NMR spectroscopic data. The reactivity ratios were r_sty = 1.776; r_moa = 0512 for MOA, and r_sty = 1.142; r_mua = 0.507 for MUA, respectively. Photopolymerization behaviors of MOA and MUA were also investigated using the photoDSC technique and the rate of polymerization of MUA is higher than that of MOA under the same conditions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2264–2272, 2005     

微波辐射合成百里香酚的研究

以间甲酚为原料,在微波辐射下与异丙醇通过付克-烷基化反应生成了百里香酚,探讨了反应工艺条件,并采用GC-MS、IR和1H NMR等手段对产物进行了表征。结果表明,在微波辐射下,使用固体超强酸SO_4^(2-)/ZrO_2-TiO_2为催化剂,n(间甲酚)∶n(异丙醇)=1∶5,反应时间15 min,催化剂用量为原料间甲酚质量的8%,微波功率600 W,回流温度条件下百里香酚得率为59.2%。     

Synthesis and polymerization of γ-ethyl-L-glutamate derivatives of nucleic acid bases

Summary -Ethyl-L-glutamate derivatives having pendant nucleic acid bases, that is, uracil, adenine and theophylline were synthesized. The -ethyl-L-glutamate having theophylline moiety was polymerized by using the N-carboxyamino acid anhydride (NCA) method.     

微波辐射合成百里香酚的研究

以间甲酚为原料,在微波辐射下与异丙醇通过付克-烷基化反应生成了百里香酚,探讨了反应工艺条件,并采用GC-MS、IR和1H NMR等手段对产物进行了表征。结果表明,在微波辐射下,使用固体超强酸SO_4~(2-)/ZrO_2-TiO_2为催化剂,n(间甲酚)∶n(异丙醇)=1∶5,反应时间15 min,催化剂用量为原料间甲酚质量的8%,微波功率600 W,回流温度条件下百里香酚得率为59.2%。     

Step-growth polymerization of guanamines with unsaturated aldehydes

Summary In acid medium and at temperatures from 50 to 100°C the resins from three different guanamines and three different unsaturated aldehydes were synthesized. The products were red coloured resins, which were soluble in organic solvents and were able to cure with hexamethylenetetramine to form hard and almost insoluble products. Using a combination of NMR and GPC methods it was possible to predict the course and the mechanism of the reactions. The rates of the reactions depend on the reaction conditions and on the type of the monomer.     

Step-growth polymerization of unsaturated aldehydes with diaminodiphenylmethane

Step-growth polymerization of diaminodiphenylmethane and unsaturated aldehydes (crotonaldehyde, cinnamaldehyde) proceeded easily in toluene at reflux temperature. Resins with molecular weights up to 1,500 g/mol were formed. In the first step of the reaction, the amino and the aldehyde groups reaction were predominate while the double bonds dominated to a lesser extent. The portion of unreacted monomers was under one percent. The resins consisted of oligomers with -CHNH-, -CH=N-, and -CH=CH-groups, which further reacted to form highly crosslinked resins. Kinetic data, the heat of the addition, the heat of condensation, and the activation energy were calculated. Faculty of Chemistry and Chemical Technology, Askerceva 5, 1001 Ljubjana, P.O.B. 537, Slovenia.     

Synthesis and characterization of bio-based benzoxazines derived from thymol

In the present study, bio-based benzoxazine resins were synthesized from bio-based phenolic compound; thymol, and three different amines; ethylamine, aniline and 1,6-diaminohexane, and paraformaldehyde by solvent-free condensation reaction. The chemical structures of bio-based benzoxazines; T-ea (thymol, ethylamine), T-a (thymol, aniline), and T-dh (thymol, 1,6-diaminohexane) were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared (FTIR) spectroscopy, elemental analysis, and high-resolution mass spectrometry. The curing studies of T-ea, T-a, and T-dh bio-based benzoxazines were performed by stepwise thermal treatment at 150, 175, 200, 225, and 250 °C. The polymerization (ring-opening and crosslinking reactions) of T-ea, T-a, and T-dh bio-based benzoxazines was investigated by FTIR spectroscopy. Cure analysis was conducted using differential scanning calorimetry and the changes in thermal properties of the T-ea, T-a, and T-dh bio-based benzoxazine resins and their corresponding thermally crosslinked polybenzoxazines PT-ea, PT-a, and PT-dh were studied by thermogravimetric analyzer. The results indicated that all the thymol-based polybenzoxazines have shown enhanced thermal stability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47371.     

Oxidative polymerization of para-substituted styrene derivatives: Synthesis,characterization and kinetics study

Synthesis and characterization of four new polymeric peroxides of styrene monomers with substituents in the para-position are discussed. NMR spectroscopy and elemental analysis confirm the alternating copolymer structure with peroxy bonds in the backbone. The thermal degradation of the polyperoxides has been studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The measured highly exothermic heat of degradation of these polymers is nearly the same as that of poly(styrene peroxide). Electron-impact mass spectroscopy (EI-MS) supports alternating peroxide units in the polymer chain. Kinetics of oxidative polymerizations have been studied for various para-substituted styrene monomers in toluene in the presence of a free radical initiator 2,2′-azobisisobutyronitrile (AIBN) at 40–50 °C and 100 psi oxygen pressure. Interestingly, both electron-withdrawing and electron-donating substituent groups in the para-position increases rate of oxidative polymerization. Theoretical studies have been performed using density functional theory (DFT) to support the order of oxidation rates.     

Role of unsaturated groups in glow discharge polymerization

The role of unsaturated groups of the starting compounds in glow discharge polymerization was investigated by elemental analysis, infrared spectroscopy, and ESCA. Tetramethylsilane (TMS), trimethylvinylsilane (TMVS), and ethyltrimethylsilane (ETMS) were used as starting materials. Glow discharge conditions (W/FM value meaning the rf power input per mass of the monomers) as well as a degree of the unsaturation of the starting materials had strong influences upon the polymer deposition rate and the elemental composition of the formed polymers. The C_1s and the Si_2p spectra showed that the chemical composition of these polymers was distinguished by either presence or absence of the unsaturated groups in the starting compounds rather than kind of the unsaturated groups. The polymer formation, when the monomers containing double and triple bonds were served, is proceeded not only through these unsaturated bonds but also through the cleavage between Si and C atoms.     

Synthesis of unsaturated aldehydes

Olealdehyde, linolealdehyde and stearolaldehyde were prepared from the corresponding acid chlorides by reduction with lithium tri-tert-butoxyhydroaluminate. Multiple bond location by means of ozonolysis techniques and determination of configuration of the double bond by spectral techniques indicate that this reaction proceeds without substantial bond migration orcis,trans isomerization. Presented at AOCS Meeting, Chicago, October, 1967. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Step-growth polymerization of unsaturated aldehydes with aliphatic amines

The step-growth polymerization of unsaturated aldehydes (acrolein, crotonaldehyde, cinnamaldehyde) and aliphatic amines (butylamine, ethylenediamine, triethylenetetramine, diethylenetriamine, hexamethylenediamine) took place intensively in the temperature range between 50 and 90°C. The rates of individual reactions depended on the type of individual aldehydes and amines. The quantity of individual unreacted monomers was mostly under 1%. The average molecular weights of oligomers were between 290 and 710. The individual resins consisted of oligomers with free ? OH, ? NH, ? CH?N? , and ? CH?CH? groups, which are further able to cross-link the resins with three blocked isocyanate to insoluble, elastic film with high adhesion to glass and metal substratum. © 1994 John Wiley & Sons, Inc.     

Synthesis of polymers having arylene-vinylene units by palladium-catalyzed hydroarylation polymerization of diethynylbenzene derivatives

Summary Arylene-vinylene-containing polymers with fully aromatic backbone structures were prepared by the palladium-catalyzed hydroarylation polymerization of diethynylbenzene derivatives with diiodobenzene and alkylmalonate anions as a hydride source. For instance, the polymerization of 1,4-bis(4'-dodecyloxy)phenylethynylenebenzene, diiodobenzene, and sodium diethyl benzylmalonate was carried out at 80°C for 2 days in 1,4-dioxane in the presence of Pd(OAc)₂ / tri-o-tolylphosphine (7 equiv. to Pd) to produce a polymer (M _n= 6,390, M _w/M _n= 1.53) in high yield (86 %). Using various diethynylbenzene derivatives, polymers having arylene-vinylene units were also obtained in high yields. Received: 16 December 1999/Accepted: 20 January 2000     

Hydrozirconation for unsaturated fatty acid derivatives

In the hydrozirconation reaction, developed by Schwartz and coworkers,bis(π-cyclopentadienyl) zirconium hydridochloride Cp₂-Zr(H)Cl, is added to the double bond of an olefin. The organozirconium intermediate can be functionalized by reaction with a variety of electrophiles such as oxygen, halogens, acetyl chloride and carbon monoxide. Furthermore, the double bond can be reformed by treatment with a hydride acceptor such as triphenylmethyl tetrafluoroborate. When a short-chain internal olefin is hydrozirconated, the initially formed alkylzirconium intermediate is rapidly isomerized to a compound in which the zirconium moiety is bound to the sterically least hindered position, which most often is the terminal position. The isomerization occurs rapidly at room temperature in contrast to the corresponding organoboron or aluminum compounds, which slowly positionally rearrange only at elevated temperatures. Because of the facile isomerization of internal alkylzirconium compounds to the terminal ones, we investigated application of the reaction to unsaturated fatty acids such as oleic and erucic acids. However, reactions on long-chain alkenes (such as oleic acid) are frequently much slower than those conducted on shorter-chain alkenes, and attention must be given to optimizing the reaction conditions if good yields are to be obtained. It would also be necessary to find an easily removable protecting group for the carboxylic function, as Cp₂Zr(H)Cl reduces carboxylic acids to alcohols. We found that the 4,4-dimethyl-2oxazoline function is a suitable protecting. group, and therefore synthesized the oxazolines from oleic acid and erucic acid. Hydrozirconation of the 4,4-dimethyl-2-oxazoline of oleic acid followed by oxidation witht-butyl hydroperoxide and conversion to methyl esters, gave methyl 3-hydroxy and methyl 18-hydroxy stearate in 13% and 17% yield, respectively. The relatively low yield is due to competing hydrogenation, the mechanism of which is discussed. Recent results indicate that the carboxyl group can be protected ast-butyl esters in the hydrozirconation and that oleyl alcohol derivatives can also be used. To understand the isomerization pattern in hydrozirconation, the reaction with α,β- and β,γ-unsaturated fatty acid oxazolines is discussed. Possibilities of making the hydrozirconation reaction catalytic by binding of the hydrozirconation reagent to a solid support as well as the synthetic potential in combining hydrozirconation with the olefin metathesis reaction are briefly reviewed.     

Preparation and polymerization of isopimaric acid derivatives

Isopimaric acid is a typical rosin compound and can account for 30% of the total mass of slash pine rosin. The molecular structure of isopimaric acid derivatives features an unsaturated double bond at the C13 position, opening up the possibility of their industrial polymerization. In this study, isopimaric acid (95.4%), methyl isopimarate (99.5%), and allyl isopimarate (95.1%) were prepared as highly pure monomers. New experimental results are presented and mechanisms based on the investigation of free-radical polymerization under UV irradiation are proposed. New rosin monomers for potential value-added utilization of woody biomass are also identified. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47817.     

Oxidation of unsaturated fatty acid derivatives and vegetable oils

The present review reports the current literature of the last 10 years on selective oxidation reactions of fatty acid derivatives and vegetable oils. The work is structured in divisions including epoxidation, radical oxidations, Wacker‐type oxidation, dihydroxylation and C=C double bond cleavage.