Diacrylate monomers

The hydroxyl groups can be esterified normally the interesting diacrylate monomer (80) and the biologicaky active haloacetates (81) have been prepared in this manner. Reactions with dibasic acids have given polymers capable of being cross-linked (82) or suitable for use as soft segments in polyurethanes (83). Polycarbamic esters are obtained by treatment with a diisocyanate (84) or via the bischloroformate (85). 

The amorphous diacrylate monomers chosen for study were two commercially available monomers, p-phenylene diacrylate (PPDA) and 1,6-hexanediol diacrylate (HDDA) (Polysciences, Inc., Warrington, PA). The liquid crystalline diacrylate studied was 1,4-di-(4-(6-acryloyloxyhexyloxy)benzoyloxy)-2-methylbenzene (C6M) (13). Chemical structures of these monomers as well as pertinent physical and LC properties are given in Figure 1. All monomers were used without further purification. The ferroelectric liquid crystal mixture consisted of a 1 1 mixture of W7 and W82 (1) (Displaytech, Boulder, CO). This mixture exhibits isotropic (I), smectic A... 

Figure 1. Exotherm curves for exposure of mixtures of 10 weight percent MM and diacrylate monomers (200 ppm hydroquinone inhibitor) to medium pressure mercury lamp through Pyrex filter (I = 19.4 mW cm 2).

Fig. 39 Micrograph of polymerized uniform submicrostructure with 9 p.m line width and 50 xm line spacing. The structure was written by two-photon initiated electron-transfer free radical polymerization of diacrylate monomer Sartomer SR 349 at 775 nm via direct excitation of dye 5,7-diiodo-3-butoxy-6-fluorone(H-Nu 470) for (A) and dye 3 for (B) in the presence of Ar,Ar-dimethyl-2,6-diisopropylaniline...

Figure 3 The LC diacrylate monomer used for Strategy 1, as well as some variations of Strategy 2.

For synthesis of one lead polymer, poly(5-amino-1 -pcntanol-co-1,4-butancdiol diacrylate) (referred to as C32), 5-amino-l-pentanol (Aldrich) and 1,4-butanediol diacrylate (Scientific Polymer Products, Inc.) are required. Additional amine and diacrylate monomers can be purchased and used following the same protocol to create structurally diverse polymers that are useful for gene delivery. These monomers can be purchased from Aldrich (Milwaukee, WI, USA), Scientific Polymer Products, Inc. (Ontario, NY, USA), TCI (Portland, OR, USA), Pfaltz Bauer (Waterbury, CT, USA), Matrix Scientific (Columbia, SC, USA), and Dajac Monomer-Polymer (Feasterville, PA, USA). 

Diacrylate monomers have been prepared that are photocurable in visible light and that have small polymerization shrinkage and high X-ray contrast properties. When polymerized with 0.01 to 0.04 pm glass powder, these dental composites were easily machined into artificial teeth. 

Similar results were obtained with a resin formulation containing these new monomers as diluent and a polyurethane-diacrylate or an epoxy-diaciylate oligomer (Figure 4). The rates of polymerization were significantly increased compared to formulations based on neat mono- or diacrylate monomers and the photosensitivity (S), i.e., the energy required to reach 50 % conversion, dropped as low as 0.4 mJ cm (Table I). 

Figure 11. Synthesis of LC poly ( aminoester)s and poly( thioester)s by the polycondensation reaction between a mesogenic diacrylic monomer and bissecondary amines and bisthiols, respectively.

Broer et al. (1989) investigated the alignment of a mesogen in a diacrylate monomer before and after photopolymerization. Before polymerization, the values of birefringence and the order parameter decreased with an increase in... 

Chem. Descrip. Bisphenol A deriv. diacrylate monomer Uses Monomer for inks and varnishes... 

Chem. Descrip. Phenol-based epoxy novolac acrylate blended with neopentyl glycol diacrylate and ester diol diacrylate monomers with MEHQ inhibitor (500 ppm)... 

Cyclohexane dimethanol diacrylate. monomer, radiation-curable film... 

A modification of the oriented polymer network systems are polymer stabilized liquid crystals (PSLC) 4) being studied in detail because of their application in flat-panel displays. In these materials, photopolymerizable diacrylate monomers are usually dissolved at a concentration less than 10% in non-reactive low-molar-mass liquid crystal solvents, commonly available, along with a small concentration of photoinitiator. Typically, the addition of small amounts of monomers and photoinitiator reduces the transition temperatures of the pure low-molar-mass liquid crystals slightly, suggesting that the order in the system is not dramatically altered by the addition of monomers or initiator. In application, this solution is aligned in a particular desired state and then photopolymerized. Photopolymerization is preferred to thermal free-radical polymerization, because photopolymerizations are very fast and because the temperature of photopolymerization can be controlled more easily to optimize processing of the display. 

The hits identified from these screens also displayed interesting structure-activity relationships. Almost all of the top performers had a hydrophobic diacrylate monomer, and among the most effective polymers amino dialcohol and bis(secondary amines) monomers were well represented. In vivo evaluation of the best-performing polymer, labeled C32, was compared to PEI for toxicity and DNA delivery in a mouse xenograft tumor model with human prostate cancer cells. C32 transfected a luciferase DNA plasmid fourfold better than PEI and 26-fold more efficiently than the naked... 

Researchers also noted that termination of these polymers with an amine or a diacrylate monomer unit had a dramatic... 

Figure 12 (a) Synthesis of poly(p-amino ester)s created by Langer etal. Two approaches to the synthesis have been taken by reacting a diacrylate monomer with a diamine (eqn [1 ]) or a diac late with a monoamine nnonomer (eqn [2]). (b) Exampies of some of the monomers expiored by Langer etal. to create their poly(p-amino ester) library [107,108]. Adapted from Lynn, D. M. Anderson, D. G. Putnam, D. Langer R J Am Chem. Soc. 2001, 123, 8155. ... 

Zhao and coworkers [234, 235] reported that an azobenzene polymer network can also optically align ferroelectric liquid crystals. This was done by dissolving two chiral dimethacrylate and one chiral diacrylate monomers containing azobenzene groups in a commercial ferroelectric liquid crystal host. The monomers were illustrated as follows ... 

Cationic lipopolymers may be prepared by reacting a diacrylate monomer with a poly(ethyleneimine) as shown in Figure 6.8. The... 

In a study of polymerization kinetics of photocurable compounds based on an epoxy acrylate oligomer and three analogous diacrylate monomers... 

The main problem of styrene is high emission, which restricts applications in closed compartments (e.g., naval application). Styrene emission is a health hazard (threshold value of 50 ppm). The need to rednce the volatile organic compound (VOC) is not only expressed in government regulations, but also equally and persuasively by various environmental concerns. The evaporation of styrene can be reduced by the addition of waxes or pyrogenic silicic acid with hydrophilic and hydrophobic end groups. However, such additives may affect the interfacial properties of composites made out of polyester resins. Some styrene-less UPE resin formulations using diacrylate monomers have been reported [71]. However, mostly styrene is used as a reactive diluent in UPE resins. 

Compositions that contain an isosorbide diacrylate monomer exhibit a significantly improved methyl ethyl ketone (MEK) rub resistance. The test consists of measuring the number of times a cotton swab that has been soaked in MEK solvent is rubbed across the image until the image is damaged. The MEK rub test is a semi-qual-... 

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