Photocatalytic and Thermal Degradation of Poly(methyl methacrylate), Poly(butyl acrylate), and Their Copolymers

Abstract

The photocatalytic and thermal degradations of poly(methyl methacrylate), poly(butyl acrylate), and their copolymers of different compositions were studied. The photocatalytic degradation was investigated in o-dichlorobenzene in the presence of two different catalysts, namely, Degussa P-25 and combustion synthesized nanotitania (CSN-TiO2). The samples were analyzed by using gel permeation chromatography (GPC) to obtain the molecular weight distributions (MWDs) as a function of reaction time. Experimental data indicated that the photodegradation of these polymers occurs by both random and chain end scission. A continuous distribution kinetic model was used to determine the degradation rate coefficients by fitting the experimental data with the model. Both the random and specific rate coefficients of the copolymers decreased with increasing percentage of butyl acrylate (BA). Thermal degradation of the copolymers was investigated by thermogravimetry. The normalized weight loss profiles for the copolymers showed that the thermal stability of the copolymers increased with mole percentage of BA in the copolymer (PMMABA). The Ozawa method was used to determine the activation energies at different conversions. At low acrylate content in the copolymer, the activation energy depends on conversion, indicating multiple degradation mechanisms. At high acrylate content in the copolymer, the activation energy is independent of conversion, indicating degradation by a one-step mechanism.

Photodegradation of Polymer Materials Used for Film Coatings of Controlled‐Release Fertilizers

“…Moreover, biodegradable materials demand more stringent storage conditions [13,14]. The photochemical activities of polymers can be increased by the addition of photocatalysts [15][16][17]. Shang et al [15] incorporated TiO 2 nanoparticles into polystyrene (PS) plastics and achieved a 22.5 % weight loss under 150 h of ultraviolet (UV) light irradiation, whereas without the addition of TiO 2 nanoparticles, the weight loss was only 12.0 %.…”

“…The photochemical activities of polymers can be increased by the addition of photocatalysts [15][16][17]. Shang et al [15] incorporated TiO 2 nanoparticles into polystyrene (PS) plastics and achieved a 22.5 % weight loss under 150 h of ultraviolet (UV) light irradiation, whereas without the addition of TiO 2 nanoparticles, the weight loss was only 12.0 %. Zhao et al [18] introduced TiO 2 nanoparticles into PE to form a complex film that showed a high photocatalytic activity under UV light and sunlight.…”

The structure and property evaluation of electrospun porous fibrous membrane based on the copolymer of styrene and butyl acrylate

“…3. The homopolymer PBA's end groups which were generated by the adopted initiator had a great influence on its thermal degradation; thus the homopolymers of BA synthesized by different initiators began to degrade at different temperatures, ranging from 250 to 320°C [26][27][28][29][30][31]. However, we found from TG curves that the fibrous membranes did not degrade at the temperature below 380°C; additionally, the DTG curve of each fibrous membrane showed only one peak.…”

Preparation of poly(methyl methacrylate) nano-latexes via UV irradiation in the presence of iron aqueous solution

“…This is a striking advantage for both classical polymerization of monofunctional monomers and modern curing applications. The polymerization of vinyl monomers sensitized by inorganic photoinitiators in the presence of an electron donor compound has attracted much attention [19][20][21][22][23][24][25]. Many of studies involved the use of compounds of Ti [19,20], Ru [21], Co [22], etc.…”