Biodegradable Mulching Films Based on Polycaprolactone and Its Porous Structure Construction

Area of Science:

• Materials Science
• Polymer Science
• Agricultural Science

Background:

• Polycaprolactone (PCL) is a biodegradable polyester with potential for mulching films.
• Current PCL mulching films have limitations in temperature-increasing and moisturizing properties.
• Rational structural design is key to improving PCL film performance.

Purpose of the Study:

• To enhance the temperature-increasing and moisturizing properties of PCL mulching films.
• To investigate the effect of a nanoporous structure on PCL film performance.
• To evaluate the PCL nanoporous film's efficacy in soil temperature, moisture retention, and weed suppression.

Main Methods:

• Fabrication of PCL nanoporous thin films using thermally-induced phase separation (TIPS).
• Characterization of soil temperature increase and water vapor transmission rate (WVTR).
• Assessment of weed biomass suppression and thermal stability (onset decomposition temperature).
• Investigation of degradation mechanisms in varying pH conditions.

Main Results:

• Nanoporous PCL (np-PCL) films demonstrated enhanced soil temperature (17.81 °C) compared to conventional PCL (17.42 °C) and PBAT (17.50 °C).
• np-PCL exhibited a lower water vapor transmission rate (637 gm⁻²day⁻¹) than PCL (786) and PBAT (890), indicating improved moisture retention.
• Weed biomass under np-PCL was significantly reduced (0.35 kg m⁻²) compared to PCL and PBAT.
• np-PCL showed good thermal stability with an onset decomposition temperature of 295 °C.

Conclusions:

• Introducing a nanoporous structure to PCL significantly enhances its temperature-increasing and moisturizing properties for mulching applications.
• np-PCL films offer a viable biodegradable alternative to conventional mulching materials, improving crop environment and reducing weed proliferation.
• The study underscores the importance of structural modification in PCL for advanced biodegradable agricultural materials.