Synthesis of bicyclo[2.2.1]hept-2-yloxyethyl acrylates and saturated acid esters derived from them

New reactive monomers, bicyclo[2.2.1]hept-2-yloxyethyl acrylates, were prepared by esterification of monoethers derived from ethylene glycol and bicyclic alcohols with acrylic acid, using naphthalene-1,5-disulfonic acid as a new effective catalyst. The related propionates and isobutyrates were prepared by hydrogenation of these acrylates.     

Thiol‐ene photopolymerization for efficient curing of vinyl esters

Monomers for radical photopolymerization based on vinyl esters (VEs) have recently been identified as suitable alternatives to (meth)acrylates on account of their low irritancy and cytotoxicity. The drawback of most VEs with abstractable hydrogens is their relatively low reactivity compared with (meth)acrylates. Within this article, we proved by photo‐differential scanning calorimetry measurements and real‐time Fourier transform infrared spectroscopy that the thiol‐ene concept is able to improve the photoreactivity of these VEs to a large extent to a level between those of acrylates and methacrylates. Other VEs have now a reactivity of at least the level of similar acrylates. Mechanical properties as determined by Dynamic Mechanical Analysis and Charpy impact tests showed significant toughening of these materials. Furthermore, we were able to confirm low toxicity of all components by osteoblast cell culture experiments. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

溶有增粘树脂的丙烯酸酯乳液共聚及压敏胶的性能

用一步法将溶有松香或氢化松香的丙烯酸酯单体进行乳液共聚合时，由于增粘树脂分子的自由基链转移作用使单体的转化率明显降低．先将大部分丙烯酸酯单体进行乳液共聚制得种子乳液，再将溶有增粘树脂的剩余丙烯酸酯单体加到种子乳液中进行第二步乳液共聚合，可显著提高单体的总转化率．用ＴＥＭ对分步聚合所得复合乳液的粒子形态进行了观察并对第二步乳液共聚合的机理进行了讨论．用分步乳液共聚合的方法制得的增粘树脂 丙烯酸酯复合乳液共聚物的压敏胶粘性能较一步法有很大的提高．     

Efficient Curing of Vinyl Carbonates by Thiol‐Ene Polymerization

Vinyl carbonates have recently been identified as a suitable alternative to (meth)acrylates, especially due to the low irritancy and cytotoxicity of these monomers. The drawback of some vinyl carbonates containing abstractable hydrogens arises through their moderate reactivity compared with acrylates. Within this paper, we use the thiol‐ene concept to enhance the photoreactivity of vinyl carbonates to a large extent to reach the level of those of similar acrylates. Mechanical properties of the final thiol‐ene polymers were determined by nanoindentation. Furthermore, low toxicity of all components was confirmed by osteoblast cell culture experiments.     

Head-to-head vinyl polymers. V. Preparation and characterization of alternating head-to-head copolymers of alkyl acrylates with alkyl methacrylates

Alternating head-to-head (h-h) copolymers of methyl or n-butyl acrylates with the corresponding methacrylates were synthesized by alternating copolymerization of ethylene with citraconic anhydride, followed by esterification and Characterization. The respective equimolar (1:) head-to-tail (h-t) copolymers were also prepared by conventional radical copolymerization as comparison. The alternating, relatively low molecular weight h-h copolymers obtained showed softening, glass transition, and degradation temperatures somewhat higher than those displayed by the 1:1 h-t copolymers. After pyrolysis the main decomposition products from both h-h and h-t copolymers were alcohols, acrylates, and methacrylates. Furthermore, the ratios of alcohols to acrylates were larger for the h-h than for the h-t copolymers and smaller for the methyl than for the n-butyl esters.     

Synthesis and photopolymerization kinetics of multifunctional aromatic urethane acrylates containing tertiary amine group

Two multifunctional aromatic urethane acrylates, based on 2, 4‐toluene diisocyanate (2, 4‐TDI), β‐hydroxyethyl arcylate (HEA), and synthetic multifunctional hydroxyl compounds, were synthesized by classical condensation reaction. FTIR was used to monitor the process of the reaction. The photopolymerization kinetics of the urethane acrylates with different photoinitiators was studied by Real‐Time Infrared Spectroscopy. The results indicated that different from the commercial urethane acrylate CN 975, the synthetic multifunctional urethane acrylates could be efficiently initiated by BP without the addition of any co‐initiators as they have tertiary amine structures. Copyright © 2008 John Wiley & Sons, Ltd.     

An efficient synthesis of alkyl α-(hydroxymethyl)acrylates induced by DABCO in an aqueous medium

Alkyl α-(hydroxymethyl)acrylates are prepared in high yields on a synthetic scale by hydroxymethylation of the corresponding acrylates using 30% aqueous formaldehyde in THF or DME as solvent and DABCO as the catalyst.     

Poly(ester urethane acrylates) and holographic properties of formulations on their basis

Poly(ester urethane acrylates) with unsaturated bonds in stiff blocks have been synthesized from oligo(ester acrylates) containing functional groups. The structure and mechanical properties of the block copolymers thus prepared have been studied before and after UV cure. On the basis of the said poly(ester urethane acrylates), light-sensitive formulations for holographic recording have been designed. The formation of holographic gratings under illumination by an Ar laser light has been investigated. The formations under study offer promise as photostructuring media for holography.     

Copolymerization of cyclopropyl-substituted dioxolanylmethyl acrylates with styrene and synthesis of photosensitive copolymers

Radical copolymerization of new monomers, cyclopropyl-substituted dioxolanylmethyl acrylates, with styrene in benzene solution was studied at low conversions. The copolymer compositions and the relative activity constants and Alfrey-Price constants of cyclopropane-containing dioxolanylmethyl acrylates were determined. The sensitivity of the copolymers obtained to UV radiation was studied, and the possibility of using them as photoresists was revealed.     

Thermoanalytische Charakterisierung Strahlengehärteter Polymerfilme

Thermo-oxidative and thermo-mechanical stabilities of radiation-cured acrylates and epoxides were examined by TG, DMA and DSC.The polymeric trifunctional acrylates PETIA, TMPTA and THEIC displayed the highest temperatures of onset of degradation. The high crosslinking density of the films resulted in an almost temperature-independent complex E-modulus, as measured by DMA. With increasing degree of ethoxylation or propoxylation of the monomers, decreases in thermal stability and strength were found. For difunctional polymeric acrylates and epoxides, the glass transition temperature was measured.The average degree of curing of UV-cured epoxy films can be determined from the temperature of the maximum in the loss modulus (E_max.This revised version was published online in November 2005 with corrections to the Cover Date.     

Influence of the secondary functionality on the radical‐vinyl chemistry of highly reactive monoacrylates

The impact of secondary functionalities on the radical‐vinyl chemistry of monoacrylates characterized by secondary functionalities that dramatically enhance their polymerization rate was elucidated utilizing experimental and computational techniques. Firstly, bulk interactions affecting the acrylate reactivity towards photopolymerization were removed by polymerizing at 5 wt % monomer in 1,4‐dioxane. Following deconvolution of bulk interactions impacting reactivity towards photopolymerization, a linear correlation between average polymerization rates and Michael addition reaction rate constants was observed on a logarithmic scale. This result indicates that the presence of the secondary functionality intramolecularly alters the monomer chemistry in a manner which impacts both of these distinct reaction types in a similar manner. These monomers exhibited reduced activation energies in both Michael addition and photopolymerization reactions as compared to hexyl acrylate. Reduction up to 20 ± 8 kJ mole^?1was observed for Michael addition reactions and 12 ± 1 kJ mole^?1 for photopolymerization reactions, thereby explaining the higher reactivity of the acrylates characterized by the secondary functionalities. Cyclic voltammetry experiments conducted to investigate the nature of the acrylic double bonds indicated that the rapidly polymerizing acrylates are more readily reduced as compared to traditional acrylates. Further, a distinct monotonic correlation of the irreversible cathodic peak potentials of the (meth)acrylates to photopolymerization and Michael addition reactivity was observed. The computationally estimated acrylic LUMO energies characterized by the secondary functionalities (?2.3 eV to ?2.7 eV) were also found to be lower relative to hexyl acrylate (?2.2 eV). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4859–4870, 2009     

Photopolymerization of acrylates without photoinitiators with short‐wavelength UV radiation: A study with real‐time fourier transform infrared spectroscopy

This article reports on the UV photopolymerization of acrylates without photoinitiators. Initiation of the reaction was achieved by direct excitation of the acrylates during irradiation with short‐wavelength UV light by use of the 222‐nm emission of a KrCl^* excimer lamp. The reactivity of various acrylates was studied by real‐time Fourier transform infrared–attenuated total reflection spectroscopy. The rate and the extent of the reaction within the layer were strongly dependent on the depth of penetration of UV light, which was determined by the molar extinction coefficient of the acrylate. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 894–901, 2004     

Asymmetric dihydroxylation of heteroaromatic acrylates

N- and O-Heteroaromatic acrylates were dihydroxylated with high ees and good yields. While the AD of pyridyl and pyrryl acrylates afforded diverse yields under the present reaction condition, some corresponding N-substituted pyridyl and pyrryl acrylates (1d, 1e, 1g) proved to be appropriate substrates. The diols obtained can be used as chiral building blocks for the synthesis of various biologically active molecules.     

Monitoring frontal photopolymerization by electroresistance

The frontal photopolymerization of acrylates was conducted in tube with TPO as bleachable photoinitiator and was identified to reach complete conversion in the formed polymer phase. The spatiotemporal temperature profiles of the frontal photopolymerization of acrylates were detected with a series of immobilized thermocouples along with the reactor. Monomer with high functionality resulted great summit temperature and was favorable for accelerating the traveling of polymerization front. It was found that the front traveling may be affected by the protruded thermocouples head. Based on the sudden increase of electrical resistance during rapid photopolymerization, an electrical measurement was setup to follow the front traveling of frontal photopolymerization.     

Synthesis of urethane acrylates modified by linseed oil and study on EBC coatings

In this paper, five different structural urethane acrylates modified by linseed oil were synthesized and then properties of their electron beam cured (EBC) coatings, i.e., adhesion, gloss, flexibility, impact resistance, hardness, tensile strength and elongation were studied. It was shown that these synthesizing conditions of urethane acrylates modified by linseed oil were temperate. Effect of structure of urethane acrylates modified by linseed oil on these properties of their EBC coatings was obvious, except gloss. According to synthetical properties of EBC coatings, the optimum oligomer among these was No. A, whose main chains were formed by hexane diacid, average functionality was 2, and oil content was 25.5%. With increasing of absorbed doses, these properties of EBC coatings, except gloss, changed correspondingly. It was advisable that absorbed dose wasn’t greater than 180 kGy. At higher absorbed doses, cobaltous naphthenate had obvious effect on these properties of EBC coatings, whose oil content of linseed oil was rather high.     

Synthesis and Ionic Conductivity of Network Polymer Electrolytes with Internal Plasticizers

Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal plasticizers on ionic conductivity were studied.     

Synthesis and reactivity of metal-containing monomers 49. Synthesis and structure of low-valence transition metal acrylates and their polymers

The methods for synthesis of Cu¹⁺, Fe²⁺, Cr²⁺, and V³⁺ acrylates were elaborated. The compounds obtained were characterized by elemental analyses, data of IR, X-ray photoelectron, and Mössbauer spectroscopy, magnetochemistry, and mass spectrometry. Polymeric products were obtained by liquid-phase radical polymerization of metal acrylates. Changes in the electronic state of the ions and their nearest ligand environment during polymerization were observed.     

Correlations between odour activity and the structural modifications of acrylates

Acrylates (acrylic esters) are versatile monomers that are widely used in polymer formulations because of their highly reactive α,β-unsaturated carboxyl structure. Commonly used acrylates such as butyl acrylate are known to emit a strong unpleasant odour, and the monomers are therefore potential off-odorants in acrylic polymers. However, up to now, the odour properties of structurally related acrylic esters have not been characterised in detail. To obtain deeper insights into the smell properties of different acrylates, we investigated the relationship between the molecular structure and odour thresholds as well as the odour qualities of 20 acrylic esters, nine of these synthesised here for the first time. The OT values of 16 acrylates fell within the range from 0.73 to 20 ng/L_air, corresponding to a high-odour activity. Moreover, sec-butyl acrylate and 2-methoxyphenyl acrylate showed even lower OT values of 0.073 and 0.068, respectively. On the other hand, the OT values of the hydroxylated acrylates 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate were 5–244 times higher than those of the other compounds, demonstrating that the presence of a hydroxyl group obviously favours odour inactivity.

     

三乙烯二胺催化Michael加成对(E)-β-芳(烷)氧基丙烯酸酯的立体选择性合成

以异丙醇为溶剂(或无溶剂),采用三乙烯二胺(DABCO)催化的取代苯酚(或取代苄醇)与2-丁炔酸乙酯的Michael加成反应合成了14个(E)-β-芳氧基丙烯酸酯化合物(3a~3n,3f~3n为新化合物)和3个烷氧基丙烯酸酯化合物(5a,5b和5k,5b和5k为新化合物),收率分别为85%~99%和60%~68%,其结构经1H NMR,13C NMR和HR-MS(ESI)表征。以3a的合成为例,优化了合成3的反应条件。结果表明:在最优反应条件(DABCO为催化剂,异丙醇为溶剂,于25℃反应9 h)下,3a收率92%,E∶Z99∶1。     

High-refractive index acrylate polymers for applications in nanoimprint lithography

The development of polymeric optical materials with a higher refractive index,transparency in the visible spectrum region and easier processability is increasingly desirable for advanced optical applications such as microlenses,image sensors,and organic light-emitting diodes.Most acrylates have a low refractive index(around 1.50)which does not meet the high perfo rmance requirements of advanced optical materials.In this research,three novel acrylates were synthesized via a facile one-step approach and used to fabricate optical transparent polymers.All of the polymers reveal good optical properties including high transparency(≥90%)in the visible spectrum region and high refractive index values(1.6363)at 550 nm.Moreover,nanostructures of these acrylate polymers with various feature sizes including nanogratings and photonic crystals were successfully fabricated using nanoimprint lithography.These results indicate that these acrylates can be used in a wide range of optical and optoelectronic devices where nanopatterned films with high refractive index and transparency are required.