SYNTHESIS AND PROPERTIES OF TRANSPARENT THIODIGLYCOL DIMETHACRYLATE COPOLYMER RESINS

The title compound, thiodiglycol dimethacrylate (TDGDMA), was synthesized from thiodiglycol and methacryloyl chloride by phase transfer catalysis reaction, and its structure was confirmed by FTIR and 1H-NMR analyses. TDGDMA possesses good polymerizability to produce a homopolymer resin with excellent transparency (T%, 90), moderate refractivity (nd20, 1.55), lower dispersivity (Abbe's number, 50.6) and higher glass transition temperature (Tg, 119°C). Through copolymerization with styrene (St) or styrene-4,4'-bismethacryloyloxydiphenylsulfone (BPSDMA), many properties of the copolymer such as refractive index, Abbe's number, strength, onset wavelength in the UV region and density were significantly modified. A copolymer resin with balanced properties between refractive index and dispersion was produced at the weight ratio of TDGDMA:St:BPSDMA (25:50:25), where nd20 and Abbe's number are 1.5815 and 36.5, respectively.

Chemical Modification of Silk Fibers with Ethylene Glycol Dimethacrylate

Silk fibers have been grafted with ethylene glycol dimethacrylate (EGDMA) and characteristics of the grafted silk fibers were analyzed in relation to the graft yield on the basis of the tensile properties, dyeing behaviour, durability during laundering and solubility of the specimen in NaOH solution. The amount of the acid dye absorbed by the fibers decreased with increasing graft yield, while the value of rating for washing fastness on silk fibers was almost unchanged by the graft treatment. The breaking loads of the fiber were almost unchanged whereas rigidity of the fibers increased after graft treatment. Graft treatment enhanced silk fiber durability during laundering and in NaOH solution.

GRAFTING OF ETHYLENE GLYCOL DIMETHACRYLATE ONTO SILK IN AQUEOUS ALCOHOLIC SOLUTION

The grafting of ethylene glycol dimethacrylate (EGDMA) onto silk in aqueous alcohol systems using potassiumpersulfate (KPS) in the presence of air was investigated. Effects of grafting conditions, such as concentrations of monomer,initiator and formic acid, temperature and time, on the graft yield were determined. The optimum graft conditions were foundto be: T = 80℃, t = 30 min, [KPS] = 1.85% [on the weight ofmonomer (owm)]; [formic acid] = 0.2% (V/V); [EGDMA] =80% [on the weight of fiber (owf)]. The activation energy of grafting at 50-80℃ was found to be 71.31 kJ/mol for EGDMA.Grafting equations were also evaluated. The graft yield value can be regulated by the concentration of monomer. The graftcopolymerization of EGDMA onto silk is effective in improving the crease-proofing of silk fabrics.

Synthesis of Monodisperse Poly(glycidylmethacrylate-coethylene dimethacrylate) Beads and Their Application in Separation of Biopolymers

The monodisperse poly(glycidyl methacrylate-co-ethylene dimethacrylate) beads with macroporous in the range of 8.0—12.0 m were prepared by a single-step swelling and polymerization method. The seed particles prepared by dispersion polymerization exhibited good absorption of the monomer phase. The pore size distribution of the beads was evaluated by gel permeation chromatography and mercury intrusion method. By using this media, a weak cation exchange (WCX) stationary phase for HPLC was synthesized by a new chemical modification method. The prepared resin has advantages of biopolymer separation, high column efficiency, low column backpressure, high protein mass recovery and good resolution for proteins. The measured bioactivity recovery for lysozyme was (96±5)%. The dynamic protein loading capacity of the synthesized WCX packings was 21.3 mg/g. Five proteins were completely separated in 8.0 min using the synthesized WCX stationary phase. The experimental results show that the obtained WCX resin has very weak hydrophobicity. The WCX resin was also used for the rapid separation and purification of lysozyme from egg white in 8 min with only one step . The purity and specific bioactivity of the purified lysozyme was found more than 92.0% and 70184 U/mg, respectively.

Transport Selectivity of a Diethylene Glycol Dimethacrylate- Based Thymine-imprinted Polymeric Membrane over a Cellulose Support for Nucleic Acid Bases

The binding mechanism between 9-vinyladenine and pyrimidine base thymine in methanol was studied with UV-visible spectrophotometric method. Based on this study, using thymine as a template molecule, 9-vinyladenine as a novel functional monomer and diethylene glycol dimethacrylate as a new cross-linker, a specific diethylene glycol dimethacrylate-based molecularly imprinted polymeric membrane was prepared over a cellulose support. Then, the resultantly polymeric membrane morphologies were visualized with scanning electron microscopy and its permselectivity was examined using thymine, uracil, cytosine, adenine and guanine as substrates. This result showed that the imprinting polymeric membrane prepared with diethylene glycol dimethacrylate exhibited higher transport capacity for the template molecule thymine and its optimal analog uracil than other nucleic acid bases. The membrane also took on higher permselectivity than the imprinted membrane made with ethylene glycol dimethacrylate as a cross-linker. When a mixture including five nucleic acid bases thymine, uracil, cytosine, adenine and guanine passed through the diethylene glycol dimethacrylate-based thymine-imprinted polymeric membrane, recognition of the membrane for the template molecule thymine and its optimal analog uracil was demonstrated. It was predicted that the molecularly imprinted membrane prepared with diethylene glycol dimethacrylate as cross-linker might be applicable to thymine assay of absolute hydrolysates of DNA or uracil assay of absolute hydrolysates of RNA in biological samples because of its high selectivity for the template molecule thymine and its optimal analog uracil.

The Role of Surfactant and Costabilizer in Controlling Size of Nanocapsules Containing TEGDMA in Miniemulsion

Nanocapsules with triethylene glycol dimethacrylate （TEGDMA） as core material and polyurethane as wall material used for self-healing bonding resin were prepared by interfacial polycondensation in miniemulsion. The influence of surfactant and costabilizer concentration on nanocapsules size and stability of nanocapsules was investigated. The size and its polydispersity of the nanocapsules were measured by light-scattering particle size analyzer. When the concentration of SDS were increased from 2.5wt% to 10wt%,the size decreases from 340.5 nm to 258.3 nm, PDI decreased from 0.210 to 0.111. As the concentration of HD increased, the size and PDI were both decreased, When reaching 10wt%,the size was 258.0 nm,PDI was 0.130. SDS and HD play important effect in synthesis of Nanocapsules containing TEGDMA.By changing the surfactant and costabilizer concentration it was possible to synthesize a wide variety of nanocapsules sizes. The performance and technical parameters of nanocapsules had been researched preliminarily, which built the solid foundation for the application to the self-repairing bonding resin.

Preparation of Hydrophilic and Shrink-Proofing Wool Fabrics Through Thiol-Ene Click Chemistry Reaction

To improve shrink-proofing performance and hydrophilicity of wool fabrics, the wool fibers were modified by poly(ethylene glycol) dimethacrylate(PEGDMA) through thiol-ene click chemistry reaction. Firstly, wool fabrics were reduced at room temperature with a high-efficiency disulfide bond reducing agent, tris(2-carbonxyethyl) phosphine hydrochloride(TCEP). Then the thiol-ene click chemistry reaction was initiated by dimethyl 2, 2’-azobis(2-methylpropionate)(AIBME) through the heating method. Fourier transform infrared(FTIR) spectroscopy, Raman spectroscopy, and scanning electron microscopy test results all showed that PEGDMA was successfully grafted onto wool fabric surface. Physical properties, hydrophilicity, and shrink-proofing performance were assessed. The wetting time of PEGDMA grafted wool fabrics decreased to about 3 s. After being grafted with PEGDMA, the felting shrinkage of wool fabrics rapidly decreased to about 8%. The anti-pilling properties of wool fabrics were also greatly improved to 5 class after 2 000 times of friction. Meanwhile, the load retention rate of fabrics could reach 90%. It provides a method of wool modification to improve hydrophilicity and anti-felting performance.

SYNTHESIS AND CHARACTERIZATION OF A METHACRYLATE POLYMER WITH SIDE CHAIN KETONE AND ITS DERIVATIVES

A new type of methacrylate monomer, 2-（4-benzoylphenoxy）-2-oxoethyl methylacrylate （BOEMA） was synthesized. The radical homopolymerization of BOEMA was performed at 65℃ in a 1,4-dioxane solution with benzoyl peroxide as an initiator. The oxime and thiosemicarbazone derivatives of poly[2-（4-benzoylphenoxy）-2-oxoethyl methylacrylate] poly（BOEMA） were prepared with hydroxylamine hydrochloride, and thiosemicarbazone hydrochloride, respectively. The monomer and its homopolymer were characterized with Fourier transform infrared and NMR techniques. The thermal stabilities of poly（BOEMA） and its derivatives were investigated with thermogravimetric analysis and differential scanning calorimetry. The ultraviolet stability of the polymers was compared. The antibacterial and antifungal effects of the monomer and the polymer and its derivatives were also investigated on various bacteria and fungi. The activation energies of the thermal degradation of the polymers were calculated with the Ozawa and Kissinger methods.