Poly methyl acrylate- its properties,preparation and use.
Polymethylacrylate: – commonly known as PMA , polymer of methyl acrylate. – tough leathery and flexible. -molecular formula- ( C4H6O2)n
-ACRYLIC is a generic term denoting derivatives of acrylic and methacrylic acid, including acrylic esters and compounds containing nitrile and amide groups. Polymers based on acrylics were discovered before many other polymers that are now widely employed. In 1880, A Swiss chemist named Georg W.A. Kahlbaum prepared polymethylacrylate. A flexible acrylic ester, polymethyl acrylate, was produced commercially by Rohm & Haas AG in Germany beginning in 1927 and by the Rohm and Haas Company in the United States beginning in 1931; used in sheets for laminated safety glass, it was sold under the trademarked name Plexigum. In the early 1930s a more rigid plastic,polymethylacrylate , was discovered in England by Rowland Hill and John Crawford at Imperial Chemical Industries, which gave the material the trademarked name Perspex. Rohm attempted to produce safety glass by polymerizing methyl methacrylate between glass layers. The polymer separated from the glass as a clear plastic sheet, which Rohm gave the name Plexiglas. Both Perspex and Plexiglas were commercialized in the 1930s.
Properties: 1) The solution properties of unfractionated PMA in ethyl acetate was investigated by light-scattering and viscosity techniques at 35°C. Narrow composition heterogeneity was revealed from the light-scattering measurements in different solvents justified the use of a single solvent for the copolymer characterization.
2) Reduced thermodynamic interaction for PSMA–ethyl acetate compared to PMA–ethyl acetate, but increased steric effect in the copolymer compared with the homopolymer.
1)Methyl acrylate is distilled under reduced pressure prior to use.
2)TiO2 is often selected as the inorganic components in the composite preparation because of its excellent weatherability, chemical stability, thermal stability and intensive ultraviolet absorption.
3)The coupling agent, aminopropyltriethoxysilane (KH550) is used for modification of Tio2 particles. 4)Amino groups are introduced into the surface of TiO2 during the reaction of KH550 and TiO2 in the presence of water. An amount of 30 g TiO2, 50 mL tetrahydrofuran, 4 g KH550 and1.0g water were added into a flask with a condenser
. 4)The reaction mixture was stirred magnetically and heated to 60ºC for 6 hrs. Then, the TiO2 particles modified with amino groups were filtered and dried at 60ºC for 5 hrs to a constant weight.
5)The graft copolymerization is conducted in a glass tube equipped with a magnetic stirring bar. In this reaction,0.5 g modified TiO2, deionized water, acetone and MA were added into the tube. Through several standard cycles of evacuation and backfilling with dry and pure nitrogen, the oxygen in the tube was removed. Then, the aqueous Cu3+ was injected into the system by a syringe. The volume of this reaction system was controlled at 7.5 mL by modulation with mixed solvents (deionized water/acetone = 3:1).
6)The graft copolymerization was carried out under the conditions of different reaction times, initiator concentration, pH value and temperature. When the reaction was completed, the polymerization was stopped by adding a little of HCl.
7)The crude graft copolymer was pulled out and dried at 90ºC until aconstant weight was reached. The exhaustive extraction with acetone for 12 h was performed to remove the homopolymer in the crude graft copolymer. Subsequently, the obtained PMA/TiO2 composite was dried at 60ºC in a desiccator under vacuum.
- Used in acrylics.
- Used in sheets for laminated safety glass.
- Oil resistant so used as a spinning solvent.
important questions and answers:
1.What is poly methyl acrylate? ans) it is a polymer of methyl acrylate.
2.What is the molecular weight of poly methyl acrylate? ans) molecular weight of poly methyl acrylate is 86.09 g/mol.
3.What is the glass transition temperature of poly methyl acrylate? ans) 9 degree celsius.
4. Poly methyl acrylate belongs to which class of polymer? ans) vinyl.