scholarly journals Copolymerization of n-butyl acrylate/methyl methacrylate in xylene solvent

2019 ◽  
Vol 22 (1) ◽  
pp. 120-127
Author(s):  
Nguyen-Vu Viet Linh ◽  
Nguyen Trung Duc ◽  
Huynh Dai Phu

Introduction: Copolymers are being used in a variety of fields because of their diversity and since any change could result in significant modifications. The butyl acrylate/methyl methacrylate copolymer is an extensively used polymer system with many advantages. This study aims to analyze some changes in copolymerization, from using different time or temperature of synthesis, in order to find an optimal process that can be applied in Vietnam. Methods: Copolymerization of butyl acrylate/methyl methacrylate copolymer with different butyl acrylate/methyl methacrylate monomer ratios was done using Xylene solvent. Copolymer compositions were determined from the Proton nuclear magnetic resonance spectra and Gel permeation chromatography. Results: The experimental results indicate that the copolymer was successfully synthesized. The highest molecular weight was 15,591 g/mol, with the lowest dispersity of 1.53 at 100 oC after 6 hours of copolymerization.  

2017 ◽  
Vol 14 (2) ◽  
pp. 311-319
Author(s):  
Baghdad Science Journal

This research is addressing the effect of different ferrocene concentration (0.00, 2.15x10-3, 4.30x10-3, 8.60x10-3, and 12.9x10-3) on the bulk free radical polymerization of methyl methacrylate monomer in benzene using benzoyl peroxide as initiator. The polymerization was conducted at 60º C under free oxygen atmosphere. The resulting polymers were characterized by FTIR. The results were compared with the presence and absence of ferrocene at 10% conversion. The %conversion was 3.04% with no ferrocene present in the polymerization medium and its increase to 9.06 with a first lowest ferrocene concentration added, i.e. 2.15 x10-3mol/l. This was positively reflected on the poly(methyl methacrylate) molecular weight measured by viscosity technique, especially in the presence of ferrocene.


2016 ◽  
Vol 20 (3) ◽  
pp. 126-135 ◽  
Author(s):  
Md. Ibrahim H. Mondal ◽  
Firoz Ahmed

Purpose This study aims to explore the use of knitted rag by synthesizing different grades of carboxymethyl cellulose (CMC) by applying multiple-step carboxymethylation techniques. Design/methodology/approach CMC was synthesized from knitted rag, a cellulosic waste of textile and garment industries, in aqueous ethanolic sodium hydroxide and subsequently mono-chloroacetic acid reaction medium. Low-substituted to high-substituted products were obtained from single-step to seven-step carboxymethylation of cellulose. In this way, it was possible to produce low-cost and different grades of substituted carboxymethylated cellulose. The synthesized CMC was characterized, and their physical properties were investigated. The structure of CMC and grafted CMC were investigated by Fourier transform infrared spectroscopy. Findings Solubility, CMC content, degree of substitution and molecular weight of CMC were increased gradually with the increase in the number of reaction steps, although fourth step attained the optimum. The cellulosic waste of knitted rag can easily be used to produce value-added products such as CMC and other cellulose derivatives, and that will ultimately reduce the pollution problems from this waste. Originality/value Grafting of prepared CMC film with methyl methacrylate monomer increased their strength, although decreased rigidity and moisture content because the incorporation of hydrophobic methyl methacrylate monomer was observed.


1988 ◽  
Vol 67 (10) ◽  
pp. 1295-1299 ◽  
Author(s):  
S. Baker ◽  
S.C. Brooks ◽  
D.M. Walker

A gas-liquid chromatography assay has been developed for the estimation of methyl methacrylate monomer (MMA) in whole saliva, with a lower limit of detection in the order of 1μg/mL. Healthy human dentate subjects wore recently made autopolymerized or heat-polymerized polymethyl methacrylate (PMMA) palatal appliances. MMA released into saliva was detected for up to one week after insertion of autopolymerized appliances, with a maximum concentration of 45 μg/mL in whole saliva or 180 μg/mL in the salivary film on the fitting surface. The MMA was not detected in blood or urine. MMA was also present in the saliva of volunteers wearing appliances which had been heat-polymerized at 70°C for one hr but not cured at 70°C for three hr. The maximum amount of monomer released by an autopolymerized base plate was 29.5 μg in the first hour, which, while not a toxic or primary irritant dose, could possibly sensitize patients or elicit an allergic reaction. For minimization of monomer release, autopolymerized appliances should be immersed for 24 hr in water before being worn.


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