Bio-based materials have become increasingly popular in recent years. Currently, many research institutions and companies are trying to use biological waste such as leaves, peels and husks to make bio-based materials or composite materials.
Researchers at Taylors University, Elite College of Arts and jewelry 3d printing technology and the University of Nottingham (all in Malaysia) are trying to use durian shells to create 3D printable biocomposites.
Durian is known as the King of Fruits and is famous for its shape, taste, texture and smell. Durian is very popular in Malaysia, with approximately 3,800 tons of durian fruits and approximately 2,280 tons of durian shells produced every year. Researchers analyzed durian shells and found that the main components of durian shells are 60.45% cellulose, 13.09% hemicellulose and 15.45% lignin. These are useful biopolymers that can be blended with PLA or natural oils to form biocomposites.
The researchers first tried mixing durian shells with PLA. They first cleaned the durian shells and cut them into small pieces; then dried them and ground them into small particles; and then sieved them with a filter (the mesh size was 600 microns). sieve) to obtain particles (short fibers) of consistent size; the particles are then dried again; and finally the durian shell particles are mixed with PLA to make wires.
However, after testing, the stiffness of durian composite PLA increased significantly, but the tensile strength was only 11 MPa, which was too brittle and of no use. But the research team said that as the fiber size increases, the stiffness of durian composite PLA will also increase, but further research is needed.
As the research deepened, the researchers found that adding epoxidized palm oil as a plasticizer to durian compound PLA can improve its toughness and ductility. Specific measures also require further research.
In terms of biodegradability, researchers buried some of the material and found that about 83% of the packaging had degraded after three months in the soil.
Another method is to freeze-dry durian shells to create durian shell nanofibers, and then mix them with PLA and cinnamon oil. The durian shells are dried, ground and then sieved into a particle size of 90 microns. It is then mixed with PLA and cinnamon essential oil, and finally made into wire.
However, after testing, the strength of this wire was not ideal and did not match the theoretical calculation results. Researchers analyzed that it may be due to the agglomeration of small particles. After continuous attempts, the researchers found that the diameter of the particles has a greater impact on the strength of the wire. At present, the ideal particle diameter they have found is 100 microns, and the tensile strength of the wire can reach 29.6 MPa. Researchers have not yet deciphered the specific reasons, but they infer that it may be related to the added oils such as palm oil and cinnamon oil.
The researchers said that the performance of the current durian composite PLA is not weaker than that of ordinary PLA, and they will conduct further research to obtain biocomposites with better performance.