Fig. 5
![Fig. 5](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs43094-021-00230-6/MediaObjects/43094_2021_230_Fig5_HTML.png)
Densitogram of forced degraded samples. a 0.1N NaOH-treated REM for 30 min at 25 °C and b 0.1N NaOH-treated REM for 5 min at 25 °C
Densitogram of forced degraded samples. a 0.1N NaOH-treated REM for 30 min at 25 °C and b 0.1N NaOH-treated REM for 5 min at 25 °C