|LIU, WANGCHENG - Washington State University|
|LIU, TIAN - Washington State University|
|GUO, XIAOJIE - Washington State University|
|XIN, JUNNA - Washington State University|
|ZHANG, JINWEN - Washington State University|
Submitted to: Journal of Applied Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2016
Publication Date: 11/8/2016
Citation: Liu, W., Liu, T., Guo, X., Xin, J., Zhang, J., Liu, L.S. 2016. Poly(butylene adipate-co-terephthalate) and sunflower head residue composites: Effects of composition and compatibilization on properties. Journal of Applied Polymer Science. 134(3):44644-44651.
Interpretive Summary: Sunflower Head Residues (SHR) are byproducts of sunflower oil processing. After the seeds are removed from the heads, the SHR are discarded. However, their high fiber and pectin contents make SHR attractive for many valuable applications. In this research, SHR were chopped to small pieces of about 5 mm, blended with the biodegradable polymer, poly(butylene adipate-co-terephthalate) (PBAT), and mixed and heated in a twin-screw extruder to form bioplastics. The resultant bioplastics possessed strong mechanical properties equivalent to that of many conventional plastics. The PBAT was modified further to improve its adhesion to SHR which further improved the strength and toughness of the resulting bioplastics.
Technical Abstract: Utilizing the abundant byproducts generated from processing of agricultural materials has sustainable and cost–saving potential benefits. In this work, Sunflower Head Residues (SHR) in 3 different compositions were introduced into biodegradable Poly(butylene adipate-co-terephthalate) (PBAT) matrices to formulate PBAT/SHR composites via melt extrusion processing. Results suggested that the composition of SHR influenced composite properties such as the mechanical properties (tensile and dynamic), melt rheology and moisture resistant ability. SHR has several typical natural fiber traits with a largely increased composite modulus compared with neat PBAT and gave a reinforcement effect, but on the other hand reduced ductility. To further improve the interfacial compatibility, maleic anhydride (MA) was grafted onto PBAT’s backbone through a free radical reaction in extrusion, then a small amount of PBAT-g-MA as an in situ compatibilizer was added into the PBAT/SHR melt blend system. FTIR suggested that reaction between the anhydride and SHR’s hydroxyl group successfully occurred. As a result, PBAT-g-MA can act as an adhesive to improve composite tensile performance. SEM morphology characterization indicated PBAT’s better wetting coverage onto SHR fiber surfaces, which validated that PBAT-g-MA’s contribution improved composite tensile properties.