Table 2.

Degradation characteristics of common polymers in aquatic environments

Polymer type	Degradation time	Degradation mechanism	Major environmental factors	Key notes	References
PE	100 to 1000s of years	Photodegradation, mechanical	UV exposure, biofouling, turbulence	Slow degradation due to lack of chromophores; UV-absorbing impurities enhance breakdown	Fairbrother et al. (2019)
PP	100s to 1000s of years	Photodegradation, thermal	Sunlight, temperature, stress	UV-induced radicals promote degradation; highly hydrophobic, resisting microbial activity	Crawford and Quinn (2017); Law (2017)
PVC	10 to 100s of years	Chemical degradation, thermal	Presence of pollutants (e.g., NO₂, SO₂), pH, salinity	Releases toxic additives; chlorine content contributes to secondary pollution risks	Teuten et al. (2007); Ebrahimi et al. (2022)
PS	50–500 years	Photodegradation, mechanical	UV intensity, wave action, oxygen	UV-sensitive; phenyl rings accelerate photodegradation via free radical formation	Liu et al. (2019b); Kumar et al. (2020)
PET	100–500 years	Photodegradation, hydrolysis	UV exposure, pH, microbial activity	Hydrolyzable; degrades faster in acidic or high-UV conditions; more biodegradable than PE/PP	Zhang et al. (2021a, 2021b)
PA	20–100 years	Hydrolysis, biological	pH, microbial activity, salinity	Amide bonds enhance hydrolysis; microbial enzymes aid degradation under favorable conditions	Danso et al. (2019)
Polylactic acid (PLA)	Months to years (under ideal conditions)	Biological, hydrolysis	Temperature, microbes, moisture	Biodegradable in compost-like conditions; stable in cold aquatic environments	Chen et al. (2022b)