Study on the Precipitation Polymerization of Acrylamide and Methacrylic Acid in Ethanol by Conductimetry: Phase- Separation Prior to Polymerization

2012 ◽  
Vol 455-456 ◽  
pp. 639-644 ◽  
Author(s):  
Min Li ◽  
Hen Mei Ni
2012 ◽  
Vol 455-456 ◽  
pp. 639-644 ◽  
Author(s):  
Min Li ◽  
Hen Mei Ni

Conductimetry was employed to investigate the precipitation polymerization of acrylamide/methacrylic acid (AAm/MAA) in ethanol (EtOH). The conductivity change vs. temperature of AAm/MAA-EtOH as well as the effects of monomer ratio and monomer concentration was studied. An abrupt decrease of conductivity in AAm/MAA-EtOH was observed at ca 25°C, indicating the phase separation of monomers and EtOH. As the ratios of AAm/MAA increased from 2/1 to 5/1 (wt/wt), the phase separation temperature increased from 22 to 31°C. The higher the monomers concentration, the temperature of phase separation is lower. These results proved that the lyophobicity of methyl group of MAA dominated the phase separation and the precipitation polymerization system of AAm/MAA-EtOH, by which the microspheres were prepared, was heterogeneous prior to the polymerization.


2020 ◽  
Vol 10 (3) ◽  
pp. 277-288
Author(s):  
Aliya Nur Hasanah ◽  
Diane Fauzi ◽  
Beska Zausha Witka ◽  
Driyanti Rahayu ◽  
Rimadani Pratiwi

Ethylmorphine is an opioid that has therapeutic effects as narcotic analgesic and antitussive, which has low levels and can be misused. Hence, it is crucial to monitor by analyze the levels of ethylmorphine in blood selectively. The preparation method that can be used to extract ethylmorphine from the sample is using molecular imprinting solid-phase extraction (MI-SPE) due to its sensitivity and selectivity. This study aims to compare the result of synthesis using two different polymerization methods, and also to examine the analytical performance and characteristics of imprinted polymers from two distinct functional monomers: methacrylic acid (MAA) and acrylamide (AM). The stages of this study include the determination of association constants, synthesis of polymer MI-SPE ethylmorphine using bulk and precipitation polymerization method, extracted template from the polymer, and determined the adsorption ability, capacity, and selectivity of the polymer. MI-SPE that has been made then characterized by using Fourier-Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). The results showed that MIP with acrylamide (MIP-AM) as functional monomer and made by precipitation polymerization had better analytic performances than MIP that made by bulk polymerization, with affinity value 0.072 mg/g and homogeneity value -0.77. It is also selective toward ethylmorphine with imprinting factor value 27.43. In addition, the result of characterization using FTIR and SEM showed that MIP-AM 2, MIP-MAA 1, and MIP-MAA 2 might have a low degree of polymerization due to the presence of vinyl peaks, besides MIP-AM 2 and MIP-MAA 2 had smaller particle size than the NIP with an average value of 0,31 ± 0,21 mm and 0.28 ± 0.05 mm. Based on the result of this study, MIP-AM made by precipitation polymerization could be used to extract ethylmorphine on solid-phase extraction.


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