Biodegradation in Soil of the PHB/Wood Flour (80/20) and PHB/Sisal Fiber (80/20) Tubes

Suzan Aline Casarin,Francisco Rosário,Osvaldo Francisco De Souza Júnior,Cássia Priscila Rodrigues,José Augusto Marcondes Agnelli

doi:10.1590/1980-5373-mr-2016-0904

Abstract

This paper presents the results of a study that aimed to monitor and evaluate biodegradation in soil, by the mass loss and the mechanical properties of plastic tubes. For this work, there were extruded and injected plastic tubes made of biodegradable polymer poly(hydroxybutyrate) - (PHB) and composite PHB/Wood Flour and PHB/Sisal Fiber, both with 20% fiber. There were used three biodegradation test devices for 30, 60 and 90 days. At the end of each test, the biodegraded samples were taken from soil, washed thoroughly with water, dried and weighed to evaluate the mass loss. Mechanical properties were evaluated using flexural tests before and after biodegradation in soil. Based on the results, it was observed that all the studied tubes lost mass over the biodegradation test, and the tubes of biodegradable composites lost more weight than pure PHB.

Highlights

The synthetic polymers have a very large resistance to degradation, which makes the accumulation of these increasing in dumps, in addition, generate a exhaustion of the non-renewable source, such as petroleum
This paper presents the results of a study of the biodegradation in soil the tubes used for planting seedlings
The biodegradable polymer Poly(hydroxybutyrate) - poly(hydroxybutyrate) - (PHB) used in the development of the study was provided by PHB Industrial S/A lote FE-147 with 4% of Valerate

Summary

Introduction

The synthetic polymers have a very large resistance to degradation, which makes the accumulation of these increasing in dumps, in addition, generate a exhaustion of the non-renewable source, such as petroleum. The use of plastic tube in the early 80’s revolutionized the traditional nurseries of the plastic bag and brought advances in terms of operating income, labor reduction, possibility of automation operations. This type of container imposes radical restriction, favoring the appearance of deformation, and these deformations may remain after the nursery stage, reducing the growth of plants in the field. Even with disadvantages the use of polypropylene tubes is widely spread throughout the forest sector This type of container can reduce 38% consumption of inputs and the period of production the seedlings[6]. The tests were performed in tubes before and after the biodegradation in soil test

Results and Discussion

Biodegradation in Soil

Characterization

Mass Loss

Flexural Test

Conclusions