Search

In this work, two kinds of biomass fillers including reed and wheat straw with similar sizes at micrometer scale were used as filler and poly(butyleneadipate‐co‐terephthalate) (PBAT) as matrix to prepare high‐performance composite materials and to use for the research of enzymatic degradation. Accordingly, hard PBAT composites with average bending strength and modulus at 12 and 1100 MPa were prepared. With the progress of enzymatic degradation, water absorption of the biomass fillers to promote the degradation of PBAT matrix was clearly revealed. The strong water absorption of biomass filler led to the large degradation rate. During the degradation within 90 days, the mechanical properties of PBAT/biomass fillers composites decreased to 23.7%. This study revealed the important factors of biomass fillers affecting the degradation behavior of PBAT in composite. Highlights: • Two different biomass fillers are blended into PBAT to fabricate the composites. • All of the biomass fillers are similarly controlled at the micrometer level. • Water absorption of biomass filler promotes the degradation of the PBAT matrix. • Stronger water absorption induces quicker degradation rate. • After degradation, bending properties of PBAT composites obviously decrease. [ABSTRACT FROM AUTHOR]

In this paper, large‐size reeds were introduced into PBAT to prepare high‐performance biodegradable composites by high‐speed blending without compatibilizer. Subsequently, the effects of large‐size reeds on the composite properties and biodegradation behavior were further investigated. The length of the reed in composites reaches to ~1.88 mm. It was found that all composites showed larger modulus and flexural strength than PBAT, and a significant increase in heat deflection temperature. By mixing 60% reed and PBAT, the bending strength, bending modulus, and heat deflection temperature reached 23.9 ± 0.4 MPa, 1237 ± 143 MPa, and 71.8°C, respectively. Biodegradation tests showed that the primary bond‐breaking site of PBAT was the C=O group. Compared with pure PBAT, the composites exhibited more significant mass loss, decreased thermal stability, increased melting point, and decreased crystallinity during degradation. A surface erosion degradation model for the composites was proposed. The research provides a scientific basis for applying high‐performance biodegradable composites to biodegradable blister and injection molded products. [ABSTRACT FROM AUTHOR]

Jute fiber with high content and large aspect ratio is directly used to prepare PLA composites to show the effect on structure and properties. By comparing with bamboo powder, it is found that the large aspect ratio of jute fiber is helpful to form a crisscross structure in PLA composites to provide a strong framework. And the larger amount of jute fiber leads to the stronger framework in the PLA composites. Accordingly, the high comprehensive mechanical properties are produced of the PLA composites with jute fiber. Only through the simple blending of 70% jute fiber and PLA, the flexural strength and flexural modulus respectively reach 94.0 ± 4.4 MPa and 9116.7 ± 127.2 MPa, which obviously exceed the mechanical properties of PLA/bamboo blends. The addition of jute fiber also improves the thermal resistance of PLA composites as well as the crystallization ability and perfection of PLA. All the results exhibit the advantages of high content filling of jute fiber with large aspect ratio to modify PLA. Utilization of biomass filler with high content and large aspect ratio will provide an important methodology to expand the application capacity of fully degradable composites in many areas. [ABSTRACT FROM AUTHOR]

A biobased epoxy monomer (GA-II) derived from gallic acid for multiwalls carbon nanotubes' (MWCNTs) dispersion improvement is reported in this article. The aromatic group in its molecular structure made it to be absorbed onto the surface of MWCNTs via π-π interactions and the GA-II anchored MWCNT could be homogeneously dispersed in DGEBA matrix via sonication. That was proved by Raman and UV spectroscopy as well as scanning electron microscope. After curing reaction, the epoxy/MWCNT composites demonstrated enhanced mechanical properties, excellent thermal conductivity, and high electrical conductivity. With the addition of only 0.5 wt% GA-II modified MWCNT, the tensile strength, tensile modulus, flexural strength, and flexural modulus of the composites were improved by 28%, 40%, 22%, and 16%, respectively. The thermal and electrical conductivities were also improved from 0.15 to 0.25 W/m K (67% increased) and from 0.7 × 10−14 to 0.24 × 10−4 S cm−1 (10 orders increased). POLYM. COMPOS., 38:1640-1645, 2017. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]