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.     

Synthesis, Characterization and Reactivity Ratios of Phenylethyl Acrylate/Methacrylate Copolymers

2-Phenylethyl acrylate (PEA) and 2-Phenylethyl methacrylate (PEMA) were synthesized by reacting 2-Phenyl ethanol with acryloyl and methacryloyl chloride respectively. Homopolymers and copolymers were prepared by free radical polymerization technique using benzoylperoxide as initiator. Copolymers of PEA and PEMA with methyl acrylate (MA) and N-vinyl pyrollidone (NVP) of different compositions were prepared. The monomers and polymers were characterized by IR and NMR techniques. Thermal stability of the polymers were determined by TG analysis. The composition of the copolymer was determined using ¹H-NMR analysis. The reactivity ratios of the monomers were determined by the application of Finemann–Ross and Kelen–Tudos methods. The prepared copolymers were tested on leather for their pressure sensitive adhesive property.     

Synthesis of acrylate modified vinyl chloride and vinyl isobutyl ether copolymers and their properties

With acrylic acid, butyl acrylate and methyl methacrylate as the monomers, acrylate modified vinyl chloride and vinyl isobutyl ether copolymers were prepared by solution polymerization. Firstly, vinyl chloride and vinyl isobutyl ether copolymers were grafted with acrylic monomers to obtain a product containing acrylate grafted vinyl chloride and vinyl isobutyl ether copolymers and polyacrylate, which was then neutralized by triethylamine and dispersed into water to get a self-emulsified emulsion. The acrylate modified vinyl chloride and vinyl isobutyl ether copolymers were characterized by Fourier transform infrared spectroscopy. The mean molecular weight of grafted polymer was determined by gel permeation chromatography, and the particle sizes and their distributions of the dispersions were measured by laser light scattering. The influences of initiator concentration, acrylate content, acrylic acid content and neutralization degree upon the properties of the modified copolymers were discussed. The results show that the emulsion will be with good storage stability, and the modified polymer will be with high water resistance, impact resistance and excellent adhesion when initiator concentration is 1.5%, acrylate content is 50%, acrylic acid content ranges from 9% to 11%, and neutralization degree is between 80% and 100%.     

Associating behaviour of polyacrylamide modified with a new hydrophobic zwitterionic monomer

The nucleophilic ring opening of dicyanoketene ethylene acetal by tertiary amino monomers leads to an hydrophobic zwitterionic monomer [(dimethylammonioethoxy)dicyanoethenolate]propylmethacrylamide (DADPMA) characterized by a very high dipole moment. Hydrophobically modified water soluble polymers have been prepared by classical radical polymerization of acrylamide and DADPMA either in homogeneous medium (water/ethanol mixtures) or in micellar solution (water containing sodium dodecylsulphate (SDS)). The copolymers obtained have a high molecular weight (M _w = 2–5 × 10⁶ g mol^?1) and are water soluble for a content of DADPMA lower than 1% mole/mole. The properties of the copolymers in aqueous solution depend on the synthesis conditions, especially on the ratio ethanol:zwitterionic monomer. © 2001 Society of Chemical Industry     

Preparation of photoresist polymer by a photoreactive monomer containing N,N-diethyldithiocarbamate group

A novel photosensitive monomer with a pendant photoreactive diethyldithiocarbamoyl group, VBDC, was synthesized and copolymerized with some vinyl monomers by AIBN. The copolymers obtained have efficient photocrosslinking abilities, and are thermally stable. Therefore, there was no loss of dithiocarbamoyl group during radical polymerization, and the polymerization proceeded through vinyl group. The degree of photocrosslinking was proportional to the concentration of the photosensitive group, but photosensitivity of the polymer was not. Water-soluble photoreactive copolymers, VBDC with AAm or MA, were also prepared. AAm copolymer has a good photosensitivity by only 3 mol % VBDC incorporation. Photocrosslinking yields of these polymers depend on the viscosity of original polymers except in the case of low concentration of VBDC. The relation between copolymer composition and glass transition temperature was also investigated. From the investigation of T_g, it was concluded that the copolymer structure largely affected on ΔT_g. The mechanism of photocrosslinking was studied by photodecomposition of benzyl N, N-diethyldithiocarbamate, and the result that the decreases of sulfur content clearly related to photocrosslinking points was also obtained.     

丙烯酸（4-N，N-二甲氨基肉桂酰氧乙基）酯及其水溶性聚合物的合成及其光化学性质研究

合成了一种新型感光性单体丙烯酸(4-N，N-二甲氨基肉桂酰氧乙基)酯(DMACEA)及其与丙烯酸的共聚物P(DMACEA-co-AA)．用紫外吸收和荧光光谱研究了聚合物溶液的光敏感性，用傅立叶红外光谱研究了聚合物成膜后的光交联性及其过程．结果表明：DMACEA具有较好的光敏性，P(DMACEA-co-AA)具有较好光交联性，交联膜水溶胀和透光性也较好．     

Polymers with rigid anisotropic side groups: 1. Side chain induced crystallinity in substituted biphenyl acrylates and methacrylates

4-Hydroxy-4′-cyanobiphenyl and 4-hydroxy-4′-n-pentylbiphenyl have been converted into vinyl monomers by reactions with acryloyl and methacryloyl chlorides. All four new monomers were homopolymerized free radically to yield acrylic polymers which melt with decomposition at temperatures in excess of 200°C. Powder X-ray diffraction studies clearly show that the polymers are crystalline and suggest that the polymer backbones lie in essentially parallel planes contained within perpendicular smectic-like layers of the directly attached and rigid anisotropic side chain substituents. It is noteworthy that side chain ordering is sufficiently strong to overcome the normal conformational barriers associated with main chain methyl groups in the methacrylate polymers. Previous examples of this type of ordering have been restricted to acrylate polymers.     

含二苯甲酮结构水溶性梳状高分子紫外线吸收剂的合成

将2,4-二羟基二苯甲酮(UV-0)、聚乙二醇单甲醚(mPEG)与丙烯酰氯反应合成中间体2-羟基-4-丙烯酸酯基二苯甲酮(2H4ABP)和聚乙二醇单甲醚丙烯酸酯,然后通过自由基溶液共聚合,将聚乙二醇单甲醚丙烯酸酯与2H4ABP、丙烯酸进行共聚合合成了一系列梳状水溶性高分子紫外线吸收剂。采用FT-IR、1H-NMR、UV等手段对产物进行了结构表征。紫外测试结果表明产物在244、291、340 nm处有强紫外吸收,与UV-0相比发生了明显红移。通过分光光度计测定计算了产物的紫外吸收效果残存率并考察了产物的光稳定性,结果表明产物有较好的光稳定性。     

Antimicrobial dual-cured photopolymers of vanillin alcohol diglycidyl ether and glycerol dimethacrylate

Considering the current efforts for to develop new antimicrobial polymers from renewable resources suitable for application in environmentally friendly light-based technologies, novel dual-cured photopolymers of vanillin alcohol diglycidyl ether and glycerol dimethacrylate are developed. The kinetics of the sequential and simultaneous dual-curing processes, combining free radical and cationic photopolymerizations, is investigated by real-time photorheometry. Comparison of dual-curing systems with different ratios of biobased epoxy and acrylate monomers revealed that the increase in the acrylate content increases the photocuring rate and improves the mechanical performance (Young's modulus increases from 76.64 to 190.71 MPa) and thermal stability (the 10% weight loss increases from 227 to 274°C) of the polymers, while the increase in the vanillin epoxy content results in better antimicrobial activity. Developed photopolymers create unfavorable conditions for the growth of microorganisms and reduce their population by up to 0% in 24 h. The excellent antibacterial and antifungal activity of new photopolymers allows them to be considered as biobased alternatives to petroleum-based antimicrobial coatings, films, or optical 3D printed objects.     

Preparation of surfactant-free vinyl polymers by conventional emulsion polymerization using hydrolysable emulsifiers

Emulsion polymerizations of several vinyl monomers, styrene, methyl methacrylate, butyl methacrylate, butyl acrylate, and vinyl acetate, in water using alkali–hydrolysable cationic surfactants with a betaine ester group (1-alkoxycarbonylmethyl)trimethylammonium chlorides, as emulsifiers were carried out and properties of the resulting latices and the polymers recovered by hydrolysis and salting out were investigated. There were little influences of the surfactants and monomers used here on the polymerizations, forming stable and monodisperse latices with a mean diameter of ca. 70 nm and giving a high molecular weight of polymers at high yields. All polymers were precipitated and recovered by adding a small amount of sodium hydroxide into the latex solutions contained little amount of ionic species. Solvent-cast films of the polymers were found to have surfaces as hydrophobic as those for the corresponding pure polymers prepared by bulk polymerization.     

Amphiphilic block copolymers with pendant thiol groups in side chains by RAFT polymerization

A new synthetic approach to thiol functional, well-defined amphiphilic block copolymers, which can be used to prepare multifunctional polymers and polymeric nanoparticles, is presented. Starting with a hydrophilic macroRAFT transfer agent and hydrophobic (meth)acrylate monomers that possess protected thiol groups, amphiphilic block copolymers are prepared in high yield. It is proven that the protected thiol groups in the monomer do not interfere with the RAFT polymerization process. Polymers with defined molecular weight, narrow polydispersities (PDI < 1.30) and varying length of the hydrophobic block are presented. Polymers with thiol groups in side chains and chain ends are obtained by aminolysis. With pyrene fluorescence spectroscopy and NMR measurements, it is shown that all synthesized polymers self-assemble into micelles. Furthermore, the possible application of these new polymers is exemplified by the preparation of polymer nanoparticles.     

Evaluation of hydrophobically associated polyacrylamide‐containing aqueous fluids and their potential use in petroleum recovery

Acrylamide and tridecyl acrylate copolymers were synthesized by micellar copolymerization to obtain water‐soluble, hydrophobically modified polymers. Rheological properties of the obtained polymer solutions were evaluated and compared to those of solutions of a commercial polyacrylamide currently used in the petroleum industry. The behavior of the copolymer solutions was studied as a function of the variation of hydrophobic monomer content incorporated in the copolymer as well as the salt content of the aqueous medium, for diluted and semi‐diluted regimens. Comparative studies of such effects on the intrinsic viscosity and the critical concentration of those polymers were conducted. The increase in hydrophobic monomer content produced a sudden increase in the bulk and absolute viscosity of the polymeric solutions, a trend that was more intense from a certain concentration typical for each polymer. Salt addition led to lower bulk viscosity caused by a stronger interaction among hydrophobic groups, resulting from minimized exposure of such groups and water. The same effect was observed for the critical concentration. A comparison of the synthesized polymers with industrial polyacrylamide showed that the synthesized polymers were characterized by advantageously high shear strength and high salt resistance. However, in the absence of salts, higher copolymer amounts were needed to prepare solutions whose viscosity was the same as that of commercial polyacrylamide. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3686–3692, 2004     

水溶性疏水缔合聚合物单体的合成

水溶性疏水缔合聚合物含有大量的亲水基团和少量的疏水基团,疏水基团间的疏水缔合作用使这种聚合物具有独特的增粘、抗剪切、耐温和耐盐的溶液性能,通常采用亲水单体和疏水单体共聚制备这类聚合物。对常用亲水单体AMPS及各类疏水单体如季铵盐不饱和单体AMPDAC和DAMAB、长链丙烯酸酯,N-烷基丙烯酰胺和N-芳烷基丙烯酰胺的合成进行了综述。     

Synthesis and application properties of fluorinated aromatic copolymers

Aromatic monomers with different fluorine concentrations and structural distribution patterns were synthesized. A series of copolymers based on methyl methacrylate, acrylate, and perfluorooctylalkyl acrylate were prepared by emulsion polymerization and were subsequently used as functional coatings to prepare water‐ and oil‐repellent cotton fabrics. The composition and structure of the outmost layer of the treated cotton surface were analyzed. A strong surface segregation of fluorinated segments was found for the treated samples, as shown by X‐ray photoelectron spectroscopy analysis. The basis for an in‐depth appreciation of the relationship between the molecular structure of the monomers and the properties of corresponding copolymer‐treated materials was provided (especially with regarding to their hydrophobic and oleophobic properties). The wetting characteristics of the fluorinated copolymers were found to be dependent on the density (number of side chains per constitutional repeat unit) and regularity of the fluorinated side chains. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4410–4418, 2013     

疏水缔合型聚合物P(AM/TA)溶液性质的研究

采用沉淀聚合法制备了疏水缔合型聚合物丙烯酰胺 /丙烯酸十四酯共聚物P(AM/TA)。研究了在链结构中引入不同疏水基团摩尔分数的共聚物的溶液性质。结果表明该共聚物在w(NaCl) =1 5 %的溶液中的黏度较之水溶液有较大提高 ,表现出明显的抗盐性质 ,而临界缔合质量分数和特性黏度均出现下降趋势。该聚合物是一种性能优异的疏水缔合型增稠剂。作者对共聚物溶液的黏度 -温度性质和剪切速度对溶液黏度的影响也进行了研究。     

UV curing of composites based on modified unsaturated polyester

Synthesis and photocrosslinking of glass fiber-reinforced composites, based on epoxy acrylate-modified unsaturated polyester, have been investigated. The efficiency of the photocrosslinking process for glass fiber laminates of the polyesters that contain different comonomers has been evaluated by measuring mechanical properties. The data show (i) that 2 mm thick laminates, containing 30–40% glass fiber mats, are cured with UV irradiation for 15 sec at room temperature in air; (ii) that multifunctional acrylate or acrylether monomers added to the polyester resin improve the tensile and flexural properties of the photocured product to a greater extent than do added allylic monomers, due to the different photocrosslinking mechanisms; (iii) that the physical properties of the photocrosslinked laminates are well correlated with the molecular weight of the polyester, the amount of multifunctional monomer added, and the glass fiber content. © 1994 John Wiley & Sons, Inc.     

Synthesis and antimicrobial activities of acrylamide polymers containing quaternary ammonium salts on bacteria and phytopathogenic fungi

Three series of acrylamide monomers/polymers containing quaternary ammonium salts (QASs), i.e., acrylamide QAS monomers (QDs), homopolymers of QDs (PQDs) and copolymers of QDs with acrylate monomer (PQDCs), were synthesized and employed in antimicrobial tests against both bacteria (Escherichia coli (E. coli) and Staphylococcus albus (S. albus)) and phytopathogenic fungi (Rhizoctonia solani (R. solani) and Fusarium oxysporum f. sp. cubense race 4 (Foc4)). The antibacterial activity of the QASs was evaluated by determining the minimum inhibitory concentration (MIC) against E. coli and S. albus by the TTC coloration method, and the antifungal activity was measured by mycelia growth inhibition as well as MIC and the minimum fungicidal concentration (MFC) values. The results indicated that PQD homopolymers and PQDC copolymers showed far better antimicrobial activities than QD monomers. PQDC copolymers by incorporating hydrophobic acrylate units into the main chain of polyacrylamide backbone displayed even better antimicrobial activities, depending on QAS structure and hydrophobic content. Moreover, polymers with benzyl group attached to nitrogen atom showed better inhibitory effect on bacteria and phytopathogenic fungi. The results could assist understanding and development of future design of antimicrobial polymers as potential fungicide agents to control plant disease.     

Synthesis of superabsorbent copolymers as water manageable materials

Strongly water‐absorbing polymers based on the monomers acrylamide, potassium acrylate and magnesium methacrylate were prepared by copolymerization using ammonium persulfate as initiator and N,N‐methylene‐bisacrylamide (MBA) as crosslinking agent. The copolymers are synthesized by varying monomer, crosslinker and initiator concentrations. The experimental results shows that superabsorbents (SAPs) have good absorbency both in water and NaCl solutions. The copolymers are characterized by IR spectroscopy. Water retention in soil is enhanced by use of these superabsorbents. The SAPs use for the growth of sunflower plants is also investigated. The water retention capacity of the SAPs was carried out at 60 °C and 100 °C. Copyright © 2003 Society of Chemical Industry     

Functional polymers

2-(2,4-Dihydroxyphenyl)2H-4-methoxybenzotriazole was treated with acryloyl or methacryloyl chloride and gave 2[2-hydroxy-4-acryloxy(methacryloxy)phenyl]2H-4-methoxybenzotriazole. The two monomers were homo-polymerized and copolymerized with styrene, methyl methacrylate and n-butyl acrylate with azobisisotutyronibrile as the initiator. The monomers, homopolymers and copolymers were characterized.Functional Polymers XXXII: F. Xi, W. Bassett, Jr., and O. Vogl, J. Polym. Sci., Polym. Chem. Ed., in press.     

Reaktive polyacrylate für den oberflächenschutz

Acrylic polymers find increasing application as binders for protective coatings. The monomeric acrylic compounds easily copolymerize with each other and with many other monomers, thus permitting the synthesis of polymeric substances with very different properties. By introduction of suitable functional groups into the copolymers the synthesis of reactive polymers is possible. These products are well soluble and easily processable and can be crosslinked by the application of heat to give products of excellent chemical and mechanical resistance. The reactive groups may be introduced either by use of reactive monomers or by reaction with a suitable prepolymer. Especially acrylic polymers with hydroxyl-, amide-, N-methylolamide-, epoxy-, and active CH-groups in the molecule have received considerable attention for protective coatings. The most important types of these polymers and their crosslinking reactions are discussed with special consideration of polymers with methylolamide functions. Finally examples of important fields of application for reactive acrylic coatings are given.