Stimulated Raman Scattering During Pulsed Laser-Induced Co-polymerization of n-Butyl Methacrylate and n-Octadecyl Methacrylate

Autor: Mohammad Aslam Khan, Saira Arif, Asma Batool, Asghari Gul
Rok vydání: 2018
Předmět:
Zdroj: Arabian Journal for Science and Engineering. 44:655-662
ISSN: 2191-4281
2193-567X
DOI: 10.1007/s13369-018-3635-y
Popis: We report simultaneous photoinitiated polymerization and stimulated Raman scattering (SRS) from polymers of methacrylate monomers using a Q-switched Nd: YAG laser (second harmonic radiation at 532 nm). The monomers used were n-butyl methacrylate and n-octadecyl methacrylate together with benzoyl peroxide as initiator, dissolved in ethanol. During the interaction of focused laser pulses with the mixtures of monomers, a strong signal in the forward direction at 630.4 nm was recorded that corresponds to SRS signal originating from Raman active vibrational stretching modes of $${\varvec{\nu }}{{\varvec{s}}}$$ (C–H) of $$-\hbox {OCH}_{3}$$ with $${\varvec{\nu }}{{\varvec{s}}}$$ (C–H) of $$\alpha \hbox {-CH}_{3}$$ and $${\varvec{\nu }}{{\varvec{a}}}(\hbox {CH}_{2})$$ groups at $$2957\,\hbox {cm}^{-1}$$ in the polymethacrylate. In addition, another SRS signal at 773.2 nm corresponding to the first overtone of the referred Raman mode was also recorded. Results are presented where different compositional mixtures of the polymerizing monomers, and different laser energies were used mainly for the strongest SRS intensities that could possibly be an index of the rate and extent of polymerization.
Databáze: OpenAIRE