Novel Recycling System of Polystyrene Water Debris with Polymer Photocatalyst and Thermal Treatment
- PDF / 1,505,856 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 23 Downloads / 163 Views
ORIGINAL PAPER
Novel Recycling System of Polystyrene Water Debris with Polymer Photocatalyst and Thermal Treatment Hisayuki Nakatani1,2 · Takuma Kyan1 · Yukito Urakawa1 Accepted: 13 November 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract A poly(styrene-block-acrylic acid) containing TiO2 gel (PS-b-PAA/TiO2) polymer photocatalyst had the same density as PS and could provoke photocatalytic activity to PS particles in water. It showed photocatalytic activity to a PS containing a N–H type hindered amine light stabilizer (PS/LA-77) in water under the UV irradiation. The molecular weight decrease was ca. 10%, showing that a weaker light source and different kind of hindered amine light stabilizer (HALS) should be employed. The phthalocyanine modified photocatalyst had the activity under visible light irradiation. In addition, a N-OR type HALS (LA-81) loading worked as radical scavenger, showing that the PS autoxidation was certainly controlled. After the 144 h irradiation, the molecular weight was drastically decreased with the increases of heating temperature and time. When the heat treatment was performed by the enclosed sample with the aluminum foil, the molecular weight change behavior was considerably different between the PS and PS/LA-81. The difference was due to the chain scission mechanism. The intraalkyl radical production in PS chain allowed controlling molecular weight by the heat treatment. Keywords Polymer photocatalyst · Hindered amine light stabilizer · Polystyrene · Autoxidation
Introduction A huge amount of plastic has been produced each year and has resulted in the accumulation of immense amount of litter in a marine environment [1–10]. The plastic litter is widespread in it and provokes microplastic pollution (MP) [3, 4, 6, 9]. MP has been commonly considered as plastic particles with a size less than 5 mm [11]. It is considered that marine organisms are injured by MP such as micro-sized PS [5, 12, 13]. To decompose MP with photocatalyst is a solution method to solve the pollution. Photodegradable polymeric materials have been studied with TiO2 photocatalyst systems Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10924-020-01976-5) contains supplementary material, which is available to authorized users. * Hisayuki Nakatani h‑nakatani@nagasaki‑u.ac.jp 1
Polymeri Materials Laboratory, Chemistry and Materials Program, Nagasaki University, 1‑14 Bunkyo‑machi, Nagasaki 852‑8521, Japan
Organization for Marine Science and Technology, Nagasaki University, 1‑14 Bunkyo‑machi, Nagasaki 852‑8521, Japan
2
[14–17], and the complete decomposition certainly brings about the solution to the issue of MP pollution. However, the practical application is difficult due to being accompanied with a side reaction such as crosslinking. MP recycling is preferable although there exist in some problems such as biotic and chemical contaminations on MP surface [5, 10, 18–22]. MP is colonized by microorganisms in sea since a suita
Data Loading...
