Three kinds of phenolic resins have been synthesized at pH of 3 (with phenol/formaldehyde molar ratio of 1∶0 75 catalyzed by oxalic acid), 8(with phenol/formaldehyde molar ratio of 1∶1 4～1∶2 4 catalyzed by KOH) and 14(with phenol/formaldehyde molar ratio of 1∶1 2～1∶1 5 catalyzed by KOH), respectively. Investigation on the crosslinking reaction between phenolic resins and borate showed that resin synthesized at basic condition can chelated with borate quickly by passing CO 2 through the resin sand. The results indicated that the cured casting of the resin synthesized at pH=14 possessed the highest mechanical strength.
Hyperbranched poly(ester-amine) with terminal amine groups was synthesized by Michael addition reaction between trimethylolpropanetriacrylate (B 3 monomer) and pizine (A 2 monomer) under molar ratio of 6∶13 via a one-step procedure.It was further modified by stearyl chloride to form an amphiphilic hyperbranched polymer.The structures of these polymers were characterized by FT-IR,{}+1H-NMR,DSC and GPC analyses.Due to the existence of interior secondary amines,the modified polymer can be used as phase transferring agent to extract methylic orange from water layer to CHCl-3 layer.Both higher transferring capability and higher transferring rate were achieved at lower pH of the water phase.The extracted dye in the organic layer can be further released to the water layer under a basic condition.A possible mechanism for extracting dye by amphiphilic hyperbranched polymer was suggested.
Aliphatic hyperbranched poly(ester amine)s with terminal acrylate groups were synthesized by Michael addition reaction between pizine and trimethylol propanetriacrylate (TMPTA) under various molar ratios, and their structures were characterized by 1H NMR,GPC and DSC analysis.The multi peaks within δ 4.04～4.18 (RCH 2OCOR′) in the 1H NMR spectra were analyzed and the peaks at δ 4.15, δ 4 06～4 07 and δ 4.04 can be assigned to terminal ( T ),linear ( L ) and dendritic units ( D ),respectively.Based on 1H NMR spectra,the degree of branching ( DB) for these polymers were calculated by using both the Fréchet method and the Frey method.With the molar ratio between pizine and TMPTA increased to 1/1,the terminate units decreased,both of the dendritic and linear units increased,while M n and M w/ M n became large and the T g value became high,accordingly.Moreover,cured films were obtained through UV radiation of the polymers.The gel contents for the films decreased with increasing the molar ratio between pizine and TMPTA,which may account for the changes of their mechanical properties.
Hyperbranched poly(ester-amine) (PEAC) with terminal acrylate groups aggregated into micelles in acidic methanol-water mixed solutions at a volume ratio 1∶100,and the micellar size became large with increasing the solution pH value.Self-assembled films were successfully formed from hyperbranched polyester (PMPP) with terminal aromatic carboxylic acid groups and PEAC by layer-by-layer dipping and the process was affected by the pH value of PEAC solutions.With PEAC as the outlayer,further reaction of the self-assembled film based on acrylate groups was investigated.The film was irradiated by UV light and washed by ionizing water.The cured film fell off the substrate seriously due to the highly branched architecture of PEAC and the polymerization of acrylate groups.In addition, the self-assembled film was immersed in aqueous p-phenylenediamine solution for 72?h.Regular spherical particles in diameter of 200?nm were observed on the film surface, which was due to the strong arene-arene interaction of benzene rings introduced into the film surface through Michael addition between acrylate groups and amino groups in p-phenylenediamine.
