Studies of different kinds of fiber pretreating on the properties of PLA/sweet sorghum fiber composites

Abstract

In this article, truly degradable composites were prepared using sweet sorghum fibers which are residue of ethanol fermentation industry as reinforcement and renewable resource-based biodegradable polyester, poly (L-lactide) (PLLA) as matrix, they were fabricated by meltblending. The effect of different kinds of pretreatments (dilute sulfuric acid pretreatment, mild alkaline/oxidative pretreatment, steam explosion pretreatment) on mechanical properties of composites were investigated. Besides the composition of untreated and treated fibers as determined by Van soest method, Fourier transformed infrared (FTIR) spectroscopic and scanning electron microscopic (SEM) were also used to study the change of sweet sorghum fibers before and after pretreatments. Mechanical proper-ties testing indicated that tensile strength and impact strength of PLLA/treated fibers were improved except the dilute sulfuric acid pretreated fibers reinforced PLA composite. The mild alkaline/oxidative pretreated fiber reinforced PLA composite showed highest tensile strength of 46.12 MPa and impact strength of 8.02 kJ/m 2 which was 15.5 and 33% higher than that of the control. The SEM of impact fracture surface and DMTA test were carried out to investigate the interfacial morphology and interfacial adhesion between the fiber and matrix.

Effect of diisocyanates as compatibilizer on the properties of ramie/poly(lactic acid) (PLA) composites

“…The polar fibers have inherently lower compatibility with less polar PLA matrix, and the incompatibility may influence the composites processing and the properties of the composites. Many researches focused on using different physical and chemical methods include fiber treatments techniques such as cylation, alkali treatment, etherification, isocyanate treatment and use of coupling agents to improve interfacial bonding properties of plant fiber reinforced PLA composites [12][13][14].…”

Processing and properties of sorghum stem fragment-polyethylene composites

“…Thermoplastic composite panels were prepared with high-density polyethylene (HDPE) by hot-pressing layers of sorghum stalks and HDPE films (Qi et al, 2013). Poly(L-lactide) composites reinforced with sweet sorghum fiber residue obtained after sugar extraction of sorghum stalks were studied (Zhong et al, 2010). However, regarding the qualities of sorghum, it is worth investigating the possibility to use stem fragments to reinforce polymers.…”

Feasibility of polyethylene composites reinforced by distillers dried fibers with solubles (DDFS) after different generations of ethanol fermentation

“…14 In our previous works, renewable polylactic acid (PLA)/sweet sorghum bagasse composites were obtained using residuals from the 1.5 G bioethanol and 2 G biobutanol plants. 9,15 Besides, a PBAT/microalgae biomass residual based biocomposite was also obtained. 16 Although numerous research studies have focused on WPC production from biorenery residuals, no research has ever focused on a comparison of the mechanical and physical properties of the WPCs reinforced by the residuals from different generations of biofuel plants.…”