Polymerization of Dimethylaminoethyl Methacrylate Catalyzed by Substituted Indenyl Lanthanide(II) Complexes

The polymerization of dimethylaminoethyl methacrylate （DMAEMA） catalyzed by the 1-cyclopentylindenyl lanthanide （Ⅱ） complex （1-C5H9C9H6）2Yb （THF）2 was investigated. The results indicated that the complex （1- C5H9C9H6）2Yb （THF）2 as a single component catalyst showed high activity. The conversion of the polymerization and the molecular weight of the polymer were affected by temperature, time, amount of catalyst and solvent in the polymerization process. The catalytic activity of （1-C5H9C9H6）2Yb （THF）2 enhanced significantly when a small amount of polar solvent THF was added into the polymerization system in which toluene was selected as the solvent. The optimal temperature of polymerization was about 0 ℃. Other modified substituted indenyl lanthanide （Ⅱ） complexes also showed good catalytic activity. The order of catalytic activity of the complexes was as follows： （1-C5H9C9H6）2Sm（THF）≈ （1- C2 H5 C9H6 ）2 Sm（THF）2 〉 （1 -C5 H9 C9 H6 ）2 Yb（THF）2 〉 （1 -PhCH2 C9 H6 ）2 Sm（THF）2. The steric regularity of p oly （dimeth- ylaminoethyl methacrylate） （PDM AEM A） was characterized by 1H NM R spectra. The polymerization provided syndio- tacticity-rich PDM AEM A. The molecular weight and the molecular weight distribution of PDM AEM A were measured by gel permeation chromatography.

Copolymerization of Dimethylaminoethyl Methacrylate and Methyl Methacrylate Catalyzed by Substituted Indanyl Lanthanide(Ⅱ) Complexes

The substituted indenyl lanthanide(Ⅱ) complexes as single component catalyzed for the copolymerization of dimethylaminoethyl methacrylate and methyl methacrylate were studied. The results indicate that these complexes all show good catalytic activity and the catalytic activity is affected by the temperature and time of polymerization, amount of catalyast and the solvent as well. The yields of the copolymerization are not affected by the ratio of monomers at all. In order of catalytic activity of the substituted indenyl lanthanide(Ⅱ) complexes: (C_5H_9C_9H_6)_2Sm(THF)>(C_2H_5C_9H_6)_2Sm(THF)_2>(C_5H_9C_9H_6)_2Yb(THF)_2>KSm(C_5H_9C_9H_6)_3(THF)_3>(PhCH_2C_9H_6)_2Sm(THF)_2. The reactivity ratio of the copolymerization of dimethylaminoethyl methacrylate and methyl methacrylate catalyzed by the substituted indenyl lanthanide (Ⅱ) complex (C_5H_9C_9H_6)_2Yb(THF)_2 (r_1=0.98, r_2=0.71) were measured.

Preparation of MMA-BA-DMAEMA Nanosized Latex

The terpolymer latex of methyl methacrylate (MMA)/butyl acrylate (BA)/ dimethyl aminoethyl methacrylate (DMAEMA) with diameter of less than 100 nm was prepared by seeding semi-continuous emulsion copolymerization using APS (ammonium persulfate) / TMEDA (N,N,N, N-tetramethylethylenediamine) as the redox initiators and SDS (sodium dodecylsulfate) and OP (P-octylpolyethylene glycol phenylether) as co-emulsifiers. The factors that influenced the process stability of the copolymerization and the particle size of the latex were investigated. The addition of aqueous ammonia as coagulation inhibitor provided better process stability of the copoly- merization. The addition of acetic acid as the acidification agent caused a remarkable reduction of the latex particle size.

Preparation and Antibacterial Activity of Copolymer of Methacryloxyethyldimethyl Dodecyl Ammonium Bromide/Acrylamide

Copolymers PMDAB-co-AA with excellent antibacterial activity were designed and prepared（MDAB/AA=methacryloxyethyldimethyl dodecyl ammonium bromide with acrylamide）.The chemical structures of the copolymers were characterized by Fourier transform infrared（FTIR）,1 H NMR,13 C NMR and chemical titration.The antimicrobial activities and kinetics of the copolymer against E.coli and S.aureus were examined by viable cell counting method.The compositions of the copolymers could be easily controlled by the feed molar ratio of MDAB to AA.Furthermore,the highest antibacterial activity was achieved when the molar fraction of MDAB was in a range of 5%―20%,and the killing rate reached 100% under the test conditions.In addition,the antibacterial activity of PMDAB-co-AA was maintained and stable without any loss after 15 times of repeated usage.It was proved that the PMDAB-co-AA samples targeted at cell membrane,and caused serious damage to cell integrity and inner membrane permeation.The surrounding conditions,such as pH and inorgainc salts concentrations（CaCl2 or NaCl）,also affected their antibacterial activities.

羟丙基淀粉/DMAEMA接枝共聚物的合成与表征

为研究接枝反应条件对羟丙基淀粉接枝共聚物的影响,选用甲基丙烯酸二甲氨基乙酯(Dimethylaminoethyl methacrylate,DMAEMA)为接枝单体,过硫酸钾为引发剂,通过溶液合成法制备了羟丙基淀粉接枝共聚物.研究了反应温度、聚合时间、引发剂用量对接枝共聚反应的影响,并利用傅立叶变换红外光谱、热重分析、扫描电镜等手段对羟丙基淀粉接枝共聚物进行了表征.结果表明,DMAEMA成功接枝到羟丙基淀粉上,最佳的接枝工艺条件是引发剂用量为质量分数1%,反应时间3 h,反应温度60℃,此时接枝率达到55.3%.接枝改性在一定程度上破坏了羟丙基淀粉的结晶,导致热稳定性降低,也改变了羟丙基淀粉原有的表面形貌.