In isopropanol-water mixture, a polymer emulsion was prepared through the radical copolymerization [1,2] of styrene, acrylonitrile and 4-vinyl pyridine in the presence of azodiisobutyronitrile (AIBN) and a reactive emulsifier which was synthesized through the addition reaction of 2-isocyanatoethyl methacrylate and methoxypolyethylene glycols (Mn ≈ 2000). The polymer particles were narrowly distributed and had an average size of about 110 nm in diameter. Hydroxypropyl cellulose was used as the binder resin for the emulsion film. The emulsion coating was prepared by coating the mixture of the polymer emulsion and the water solution of the binder resin on aluminum substrate and dried at about 80°C. The resulted film can be easily removed from the substrate with water rinsing. However, once the coating is heated at a temperature which is much higher than the glass transition temperature (Tg) of the particle polymer (e.g., 150°C) for a short period of time, it could no longer be removed from the substrate by water. On the basis of the above work, a water soluble infrared-absorbing dye (IR dye) was incorporated into the emulsion coating and exposed to computer-controlled IR laser (830nm) scanning. The exposed areas could not be removed with water cleaning, whereas the non-exposed areas could still be easily removed with water. Negative images were obtained. Hence, the emulsion coating can be used in developing chemical-free CTP plates required by green printing industry.

Novel poly(aryl ether quinoxaline)s (PEQs) were prepared via a two-step procedure. First, poly (ether benzil) (PEB) was synthesized by the polycondensation of 4,4’-difluorobenzil and 4,4’-isopropylidenediphenol.Then, PEB was reacted with 1,2-diaminobenzene and 4,4'-oxydibenzene-1,2-diamine to give the PEQs. The molecular weight of the PEQs could be adjusted easily by varying the molar ratio of 1,2-diaminobenzene to 4,4'-oxydibenzene-1,2-diamine. The PEQs exhibited good solubility in common organic solvents such as NMP, DMAc, DMF, cyclohexanone and chloroform. In addition, the PEQs also had high glass transition (Tg) temperatures and good thermal properties, with an initial thermal decomposition temperature above 475 oC and glass transition temperatures above 210 oC. They also exhibited excellent resistance to strong acid and alkali.

A reversible addition fragmentation chain transfer (RAFT) agent, 2-(dodecylthiocarbonothioylthio)propanoic acid (RAFT-1), was synthesized and characterized. Diacetone acrylamide and poly(ethylene glycol)methyl ether methacrylate were polymerized in the presence of RAFT-1 to give an amphiphilic polymer(RAFT-2). A very stable and narrowly-distributed emulsion was obtained by the micellization of the amphiphilic polymer in water. The self-crosslinking resin system was prepared by adding a crosslinker (adipic dihydrazide) to the prepared emulsion. Upon the evaporation of water of the emulsion, a tough and transparent crosslinked film was prepared, which had good water/solvent resistance and certain adhesiveness.

The research relates to a method for preparing an in-situ crosslinked polymer coating. It has excellent solubility in aqueous alkaline solution, but didnt dissolve in general organic solvents and water. The crosslinked polymer coating was made through the reaction of a copolymer derived from diacetone acrylamide (DAAM) and ethacryloyloxyethyl-carbazochrome-p-toluenesulfonamide (MCTS) with a crosslinking agent, isonicotinyl hydrazide. The two components were dissolved in 3-methoxypropanol to prepare the coating solution, which was then coated to a grained and anodized aluminum substrate and dried at 120 °C for 5 min to obtain the crosslinked coating. There exists intermolecular hydrogen bond between the pyridine ring of isonicotinyl hydrazide and the sulfonamide group of the MCTS unit of the copolymer. The reaction between the hydrazide group and the carbonyl group during the drying process generated the hydrazone bond, resulting in the crosslinked polymer coating. The intermolecular hydrogen bond and the covalent bond render the coating insoluble in most organic solvents. However, the hydrogen bond was readily broken down when the coating was exposed to aqueous alkaline solution due to the ionization of the sulfonamide group, causing rapid dissolution of the coating. The coating was also used as the under-layer for the preparation of a double-layed CTP plate. The performance of the double-layed CTP plate was preliminarily studied.

With 2,2',5',2''-Terthiophene as starting material, two liquid crystalline compounds containing Schiff’s base unit were synthesized in this paper. The structure of the compounds was confirmed by FTIR and 1H NMR. The thermally induced phase transition behaviors were investigated by POM and DSC, and the temperature ranges of liquid crystal phase of the two compounds were compared. Results showed that the symmetric compound exhibited a lower clearing point temperature and broader temperature range of liquid crystal phase.