PHOTOPOLYMERS: SYNTHESIS AND CHARACTERIZATION OF POLY(4-CINNA-MOYLPHENYL METHACRYLATE) WITH GLYCIDYL METHACRYLATE

Copolymers of 4-cinnmoylphenyl methacrylate (CPMA) with glycidyl methacrylate were synthesized in methyl ethyl ketone solution using benzoyl peroxide as initiator at 70 ± 1°C. They were characterized by UV, IR, ¹H-NMR, and ¹³C-NMR spectra. Their compositions were determined by ¹H-NMR technique. The monomer reactivity ratios were determined by the Fineman-Ross and Kelen-Tüdös methods. The molecular weights ([Mbar]_w and [Mbar]_n) of the polymers were determined by GPC technique. Thermogravimetric analysis of the copolymers were carried out in air. The T_g of the polymers were determined by differential scanning calorimetry. The photocrosslinking properties of the homo and copolymers were also discussed.     

EFFECTS OF VINYL ETHERS UPON RADICAL POLYMERIZATIONS

Various vinyl ethers have been examined as additives during radical polymerizations initiated by azobisisobutyronitrile at 60°C; the monomers were methyl methacrylate (MMA), styrene (STY) and acrylonitrile (AN). For MMA and STY, the vinyl ethers were incorporated to only small extents but they caused reductions in rate of polymerization and chain length of the resulting polymer; the effects can be attributed to the low reactivities in growth reactions of radicals to which a vinyl ether unit was last added. Copolymerization of the vinyl ethers with AN was more evident but, in many cases, it was accompanied by increased rate of consumption of AN and increased chain length of the polymer. These changes can be explained in terms of a physical effect which can be likened to that believed to be responsible for the gel effect. It is considered that polymer radicals are rather tightly coiled in an indifferent solvent so that the normal bimolecular termination is impeded.     

Facile Synthesis of Hematinic Acid

Hematinic acid is conveniently synthesized in four steps from commercially available 2,3-dimethylmaleic anhydride.     

丙烯酸甲酯和甲基丙烯酸酯基团转移无规共聚的竞聚率

丙烯酸甲酯和甲基丙烯酸酯基团转移无规共聚的竞聚率⒇邹友思林东海张景辉潘容华（厦门大学化工系，厦门大学核磁共振实验室，厦门，３６１００５）单体竞聚率作为一个定量数据，对于不同投料比下共聚物组成的预计和控制，共聚反应动力学和机理研究均有重要作用。丙烯酸...     

Fungicidal activity of tributyltin alkylsulfate esters

Tributyltin alkyl sulfate esters, e.g. tributyltin dodecyl sulfate, tributyltin hexadecyl sulfate and tributyltin octadecyl sulfate, were synthesized from the reaction of bis(tributyltin) oxide and appropriate alkyl hydrogen sulfates. The resulting tributyltin alkyl sulfate esters were found to exhibit fungicidal activity on Penicillium, Aspergillus and Syncephalustrum species.     

Bis(tributyltin) oxide as a wood preservative: Its conversion to tributyltin carboxylates in Pinus sylvestris

Tributyltin compounds have been successfully used for many years as wood preservatives, although their chemical nature in timber has not been fully elucidated. This study by ¹¹⁹Sn and ¹³C NMR spectroscopy has shown that, on impregnation into Pinus sylvestris sapwood, bis(tributyltin) oxide [(Bu₃Sn)₂O] is rapidly converted to tributyltin carboxylates (Bu₃SnOCO·R) via reaction with components of the wood resin. It is further suggested that the formation of these species is a prerequisite for the known disproportionation reaction which occurs in (Bu₃Sn)₂O-treated timber.     

Influence of diluent compositions on the porous structure of methacrylate derivatives of aromatic diols and divinylbenzene

Synthesis and properties of the new aromatic tetrafunctional methacrylate monomer 2,7-(2-hydroxy-3-methacryloyloxypropoxy)naphthalene are presented. This monomer was applied for the synthesis of porous microspheres. It was copolymerized with divinylbenzene in the presence of pore-forming diluents, decan-1-ol and toluene. Influence of diluents composition on their porous structures was studied. Porous structures of the obtained microspheres in dry (from nitrogen adsorption-desorption measurements) and swollen (the inverse size exclusion chromatography method) states were compared with those synthesized from isomeric 2,3-(2-hydroxy-3-methacryloyloxypropoxy)-naphthalene and divinylbenzene.     

A general route for constructing difluoromethyl ethers

Chlorodifluoromethyl ethers are easily obtained from the corresponding alcohols. These ethers, when treated with tributyltin hydride, produce difluoromethyl ethers in high yields.