Biodegradation in simulated soil of HDPE/pro-oxidant/rice husk composites: application in agricultural tubes

Abstract

The use of agricultural waste, such as rice husk (RH), for the production of cheap and eco-friendly polymer composites has emerged as a promising field of interest. The aim of this work was the preparation of highdensity polyethylene (HDPE)-based composites reinforced with rice husk and an organic pro-oxidant (EG15) for the production of seedlings tubes. Photodegradation and degradation tests in simulated soil were performed for 90 and 180 days in order to study the decomposition of these composites. The SEM and OM images suggest that degradation of the composites samples was more extensive than the pure HDPE samples, probably because the composites present intense light absorption in the UV range, facilitating the degradation process even before biodegradation begins. In addition, after introducing RH particles in the polymeric matrix, the mechanical tensile and flexural properties, experienced significant changes, suggesting that the RH particles were homogeneously dispersed throughout the polymer matrix. Finally, the results have demonstrated that HDPE, RH, and EG15 are attractive materials for the design of polymeric composites for the production of seedlings tubes with excellent mechanical properties, being also easily decomposed in the environment once discarded.

Thermoplastic Polymers with Nanosilver Addition—Microstructural, Surface and Mechanical Evaluation during a 36-Month Deionized Water Incubation Period

“…It was observed that the cross-sections of polymers and composites on the ABS and PMMA matrices had an appearance characteristic of amorphous polymers (lamella-like structure and ductility) [ 27 ]. The microstructure of the HDPE polymer cross-section was relatively flat and smooth, with visible areas of the microfibril existence [ 28 ].…”

Biodegradable polymers: A review about biodegradation and its implications and applications

“…Another example of agricultural application is the use of biodegradable materials to produce tubes (containers used in the production of seedlings). There are already commercially available tubes of biodegradable seedlings, but they still do not meet the target dynamics of forest seedling production, as they have low mechanical strength, present cracks, and deformation of the tube structure, making handling difficult during application and transport to the field 70 . Several researchers have hence been trying to develop green materials based on biodegradable polymeric composites with a variety of lignocellulosic matrices, such as wood dust, 71 and rice husk, 70 among others.…”