The glass transition temperatures T g of butyl acrylate-methyl methacrylate copolymers obtained by free radical polymerization in 3 and 5 mol/L benzene solution have been measured using differential scanning calorimetry (DSC) and the values have been correlated using Johnston's equation with inter-i
Photothermal degradation of copolymers of methyl methacrylate and n-butyl acrylate
β Scribed by N. Grassie; R.H. Jenkins
- Publisher
- Elsevier Science
- Year
- 1973
- Tongue
- English
- Weight
- 885 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0014-3057
No coin nor oath required. For personal study only.
β¦ Synopsis
Ahstraet--The photothermal degradation of co~olymers of methyl methacrylate (MMA) and n-butyl acrylate (n-BuA) covering the whole composition range has been studied at 165 Β°.
The gaseous products, which are relatively minor, are hydrogen, carbon monoxide and methane. The liquid products are predominantly MMA, with n-BuA, n-butanol and n-butyraldehyde as minor products. Infra-red spectral changes in the residue were attributed to lactone formation and associated with butanol formation as in the purely thermal reaction The "cold ring" or chain fragment fraction becomes increasingly more abundant as the n-BuA content of the copolymer is increased.
All the products and principal features of the reaction are explained in terms of a radical process which is initiated by scission of pendant acrylate units and is propagated by a combination of depropagation and intra-and intermolecular transfer processes, the relative importance of which depends upon copolymer composition. Differences from the thermal reaction and the corresponding reaction in copolymers of methyl methacrylate and methyl acrylate are discussed.
π SIMILAR VOLUMES
Copolymers were prepared of 2-hydroxyethyl methacrylate, which is strongly hydrophilic, with hydrophobic comonomers having a low glass transition temperature, i.e., ethyl acrylate, n-butyl acrylate, and dodecyl methacrylate. The glass transition temperature, T, (1 Hz), of polymers in the dry state (
Abstraet--Diblock copolymers are obtained by addition of monofunctional telomers to aromatic diisocyanates [telomers of butyl acrylate or methyl methacrylate with mercaptoethanol]. These copolymers were synthesized in two steps: preparation of a prepolymer from a monofunctional telomer and a diisocy