# Biodegradable and Biobased Mulch Films: Highly Stretchable PLA Composites with Different Industrial Vegetable Waste

## TL;DR

This paper presents stretchable, biodegradable mulch films made from polylactic acid and vegetable waste, offering a sustainable alternative to traditional mulches.

## Contribution

The novelty lies in using nonedible vegetable waste to enhance the mechanical and biodegradable properties of PLA mulch films.

## Key findings

- Films with 20 wt% spinach stems improved PLA soil biodegradability to 38 wt% after 6 months.
- The films showed tensile strengths of 10–24 MPa and elongations at break up to 460%.
- Vegetable waste addition influenced water solubility, moisture content, and water vapor permeability.

## Abstract

Highly stretchable
biobased and biodegradable agricultural mulch
films based on polylactic acid (PLA) and 10, 20, or 30 wt % various
nonedible vegetable wastes such as spinach stems (SS), tomato pomace
(TP), and cocoa shells (CS) are prepared and characterized in this
work. The results demonstrate that appropriate PLA plasticization
and vegetable waste addition allow for obtaining films suitable for
mulching with tensile strengths in the 10–24 MPa range and
elongations at break up to 460%, depending on the kind and amount
of vegetable waste incorporated. Additionally, the developed mulches
show low water solubility (1–15 wt %) and moisture content
(1–3 wt %) with a water vapor permeability of up to 3 ×
10–10 g s–1 m–1 Pa–1, similar to that of Mater-Bi. In addition,
the type of vegetable waste added as filler were demonstrated to significantly
affect not only the films’ mentioned properties but also their
biodegradability. For instance, films prepared with 20 wt % SS were
demonstrated to improve PLA soil biodegradability, which increased
from 0 to 38 wt % for PLA composites after 6 months of a soil burial
experiment. Lastly, the developed composites contain different amounts
of plant micro- and macronutrients, indicating their potential as
fertilizers. The results found in this work represent a sustainable,
fully biobased alternative to other mulches already in the market.