Environmental biodegradability of recombinant structural protein

AbstractNext generation polymers needs to be produced from renewable sources and to be converted into inorganic compounds in the natural environment at the end of life. Recombinant structural protein is a promising alternative to conventional engineering plastics due to its good thermal and mechanical properties, its production from biomass, and its potential for biodegradability. Herein, we measured the thermal and mechanical properties of the recombinant structural protein BP1 and evaluated its biodegradability. Because the thermal degradation occurs above 250 °C and the glass transition temperature is 185 °C, BP1 can be molded into sheets by a manual hot press at 150 °C and 83 MPa. The flexural strength and modulus of BP1 were 115 ± 6 MPa and 7.38 ± 0.03 GPa. These properties are superior to those of commercially available biodegradable polymers. The biodegradability of BP1 was carefully evaluated. BP1 was shown to be efficiently hydrolyzed by some isolated bacterial strains in a dispersed state. Furthermore, it was readily hydrolyzed from the solid state by three isolated proteases. The mineralization was evaluated by the biochemical oxygen demand (BOD)-biodegradation testing with soil inocula. The BOD biodegradability of BP1 was 70.2 ± 6.0 after 33 days.

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Natural Fiber Reinforced Synthetic Polymer Composites

Diffusion Foundations ◽

10.4028/www.scientific.net/df.23.6 ◽

2019 ◽

Vol 23 ◽

pp. 6-30

Author(s):

Volkan Uğraşkan ◽

Abdullah Toraman ◽

A. Binnaz Hazar Yoruç

Keyword(s):

Mechanical Properties ◽

Carbon Fibers ◽

Natural Fiber ◽

Natural Fibers ◽

Fiber Reinforced Composites ◽

Reinforced Composites ◽

Thermal And Mechanical Properties ◽

Fiber Reinforced ◽

Promising Alternative ◽

Alternative Sources

In early composite materials, the use of petroleum based fibers such as glass and carbon fibers, aramid etc. was common. In order to reduce the dependency on petroleum based sources and environmental pollution, researchers have focused on the search for alternative sources. Natural fibers are abundant, recyclable and biodegradable plant derived materials. Besides, thanks to good physical, thermal and mechanical properties, natural fibers become promising alternative for composites. This review includes information about natural fiber reinforced composites’ components, manufacturing methods, mechanical properties and applications.

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Thermomechanical Study and Thermal Behavior of Plasticized Poly(Lactic Acid) Nanocomposites

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.317.333 ◽

2021 ◽

Vol 317 ◽

pp. 333-340

Author(s):

Mohammed Zorah ◽

Izan Roshawaty Mustapa ◽

Norlinda Daud ◽

Nahida Jumah ◽

Nur Ain Syafiqah Sudin ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Lactic Acid ◽

Thermal Behavior ◽

Food Packaging ◽

Mechanical Performance ◽

Poly Lactic Acid ◽

Solvent Casting ◽

Thermal And Mechanical Properties ◽

Hot Press

Poly (lactic acid) (PLA) is a useful alternative to petrochemical commodity material used in such as in food packaging industries. Due to its inherent brittleness, low thermal stability, and poor crystallization, it needs to improve its properties, namely in terms of thermal and mechanical performance. The plasticized PLA composites reinforced with nanofiller were prepared by solvent casting and hot press methods. Thermal and mechanical properties, as well as the crystallinity study of these nanocomposites, were investigated to study the effect of tributyl citrate (TBC) and TiO2 on the PLA composites. The addition of TBC improved the flexibility and crystallinity of the composites. Reinforcement of TiO2 was found as a practical approach to improve the mechanical properties, thermal stability, and enhanced crystalline ability for plasticized PLA nanocomposites. Based on the results achieved in this study, the composite with 3.5% nanofiller (pPLATi3.5) presented the optimum set of mechanical properties and improved thermal stability.

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Lignin-Based Polybenzoxazine Derived from Empty Fruit Bunch Fibers with Good Thermal and Mechanical Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.981.121 ◽

2020 ◽

Vol 981 ◽

pp. 121-126

Author(s):

Nurfatin Farhanah Rohimi ◽

Rasidi Roslan ◽

Nurjannah Salim ◽

Siti Noor Hidayah Mustapha ◽

Sarani Zakaria ◽

...

Keyword(s):

Mechanical Properties ◽

Condensation Reaction ◽

Curing Temperature ◽

Empty Fruit Bunch ◽

Thermal And Mechanical Properties ◽

Scanning Calorimetry ◽

Promising Alternative ◽

Mannich Condensation ◽

Polymerization Behavior ◽

Izod Impact

In this study, a renewable phenolic component was synthesized using empty fruit bunch fibers via microwave-assisted liquefaction known as Liquefied Empty Fruit Bunch (LEFB). LEFB can be used as phenolic derivative to replace petroleum-based phenol as it contains aromatic group in lignin that can be used as starting materials to synthesis polybenzoxazine resins. A Lignin-based benzoxazine (L-PBz) has been synthesized using a solventless approach from the reaction of LEFB, furfurylamine as the amine component and paraformaldehyde via Mannich condensation reaction. Two different ratios of LEFB:furfurylamine:paraformaldehyde which are 1:1:1 and 1:1:2 were investigated. The thermal properties and polymerization behavior of the L-PBz were analyzed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. In addition, cured-polybenzoxazine composites were also prepared by hot-pressing the uncured L-PBz at 250 °C for 4 hours, and the mechanical properties of the composites were assessed through Izod impact strength test. TGA analysis showed that, L-PBz with ratio of 1:1:1 exhibit a high char yield compared to 1:1:2 which is 47% vs 43%, respectively, after being heated until 900 °C. However, L-PBz with ratio of 1:1:2 showed good polymerization behavior compared to 1:1:1 which indicated by the curing temperature 215 °C vs 238 °C. L-PBz composites, which added with cellulose nanocrystal (CNC) fillers have better strength compared with the absence of fillers. As a conclusion, the aromatic structure of lignin in empty fruit bunch fibers has presented a promising alternative to replace petroleum-based phenol in polybenzoxazine synthesis.

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