Network structures from poly(β-amino ester) (PAE) were synthesized for applying as drug delivery matrix via a simplified addition polymerization method. It can hold an active organic compound (drug) that has an effec...Network structures from poly(β-amino ester) (PAE) were synthesized for applying as drug delivery matrix via a simplified addition polymerization method. It can hold an active organic compound (drug) that has an effect as antitumor activity in order to control its release. PAE was prepared from piperazine and 1,4-butandiol diacrylate with different molar ratios. The active compound was mixed with the prepared polymer while warming for 15 minutes to obtain the capsule product. The resulting polymer structures and the surface morphology of the PAE capsules before and after encapsulation with the active drug were characterized by FT-IR and SEM, respectively. Swelling and degradation behavior of PAE were studied. The characterization showed that the obtained network structure of PAE depends on the molar ratio between the reactants. The optimum ratio of the reactants was found to be 1:1. Therefore, stable and white product as well as good holding capability for drug produced. The SEM studies illustrate good dispersion and holding properties of the drug into the network structure of the prepared polymer. In vitro, the release results of the drug from the PAE capsules indicated that the capsules were able to give sustained release of drug in DMF up to 10 days at 25°C.展开更多
Some vinyl polymers/montmorillonite nanocomposites were prepared via in-situ-atom transfer radical polymerization (ATRP) in presence of clay. Methyl methacrylate, styrene and n-butyl methacrylate were involved in the ...Some vinyl polymers/montmorillonite nanocomposites were prepared via in-situ-atom transfer radical polymerization (ATRP) in presence of clay. Methyl methacrylate, styrene and n-butyl methacrylate were involved in the formation of such polymeric nanocomposites. Their dielectric properties were extensively studied to invest them in the a.c. power applications. Several dielectric parameters such as dielectric constant loss (ε") and a.c. conductivity (σ) were measured at both different frequencies (0.1 Hz to 100 KHz) and temperature ranged from (20℃ to 90℃). From the dielectric results, it was realized that the dielectric a.c. conductivity was enhanced by increasing the temperature for the four prepared polymer nanocomposites.展开更多
Hyperbranched poly(amine-ester) (HBPAE) was synthesized via pseudo-one-step process between trimethylolpropane as a core molecule and N, N-diethylol-3-amine methylpropionate as the AB2 branched monomer. The prepared p...Hyperbranched poly(amine-ester) (HBPAE) was synthesized via pseudo-one-step process between trimethylolpropane as a core molecule and N, N-diethylol-3-amine methylpropionate as the AB2 branched monomer. The prepared polymer was analyzed by IR, GPC, 1H-NMR and thermal analysis (TGA and DSC). The performance of the polymer in cement was tested by measuring the effect of 1, 3 and 5 wt% of HBPAE solutions on the properties of Ordinary Portland Cement. Water of consistency, setting times, bulk density, apparent porosity, compressive strength and combined water content of the polymer/cement pastes were studied. The results showed that water of consistency and apparent porosity decreased while setting times, compressive strength, combined water and bulk density increased with the polymer addition.展开更多
文摘Network structures from poly(β-amino ester) (PAE) were synthesized for applying as drug delivery matrix via a simplified addition polymerization method. It can hold an active organic compound (drug) that has an effect as antitumor activity in order to control its release. PAE was prepared from piperazine and 1,4-butandiol diacrylate with different molar ratios. The active compound was mixed with the prepared polymer while warming for 15 minutes to obtain the capsule product. The resulting polymer structures and the surface morphology of the PAE capsules before and after encapsulation with the active drug were characterized by FT-IR and SEM, respectively. Swelling and degradation behavior of PAE were studied. The characterization showed that the obtained network structure of PAE depends on the molar ratio between the reactants. The optimum ratio of the reactants was found to be 1:1. Therefore, stable and white product as well as good holding capability for drug produced. The SEM studies illustrate good dispersion and holding properties of the drug into the network structure of the prepared polymer. In vitro, the release results of the drug from the PAE capsules indicated that the capsules were able to give sustained release of drug in DMF up to 10 days at 25°C.
文摘Some vinyl polymers/montmorillonite nanocomposites were prepared via in-situ-atom transfer radical polymerization (ATRP) in presence of clay. Methyl methacrylate, styrene and n-butyl methacrylate were involved in the formation of such polymeric nanocomposites. Their dielectric properties were extensively studied to invest them in the a.c. power applications. Several dielectric parameters such as dielectric constant loss (ε") and a.c. conductivity (σ) were measured at both different frequencies (0.1 Hz to 100 KHz) and temperature ranged from (20℃ to 90℃). From the dielectric results, it was realized that the dielectric a.c. conductivity was enhanced by increasing the temperature for the four prepared polymer nanocomposites.
文摘Hyperbranched poly(amine-ester) (HBPAE) was synthesized via pseudo-one-step process between trimethylolpropane as a core molecule and N, N-diethylol-3-amine methylpropionate as the AB2 branched monomer. The prepared polymer was analyzed by IR, GPC, 1H-NMR and thermal analysis (TGA and DSC). The performance of the polymer in cement was tested by measuring the effect of 1, 3 and 5 wt% of HBPAE solutions on the properties of Ordinary Portland Cement. Water of consistency, setting times, bulk density, apparent porosity, compressive strength and combined water content of the polymer/cement pastes were studied. The results showed that water of consistency and apparent porosity decreased while setting times, compressive strength, combined water and bulk density increased with the polymer addition.
