Biomimetically Structured Poly(lactic acid)/Poly(butylene-adipate-<i>co</i>-terephthalate) Blends with Ultrahigh Strength and Toughness for Structural Application

The preparation of ultrastrong and super-tough polymeric materials for structural application remains a considerable challenge. To simultaneously enhance the strength and toughness of poly(lactic acid) (PLA), we successfully prepared ultrastrong and super-tough PLA/poly(butylene-adipate-co-terephthalate) (PBAT) blends by biomimetically constructing a mussel nacre-like hierarchically ordered superstructure through a simple pressure-induced flow (PIF) processing technique. The morphology, crystallization, and mechanical properties of the blends were studied. During PIF processing, the immiscible PLA/PBAT blends were forced to undergo plastic deformation, which enhanced the interaction between PBAT and PLA and resulted in the formation of an oriented nanohybrid shish-kebab-like hierarchical structure. The combination of scanning electron microscopy and two-dimensional wide-angle X-ray diffraction results demonstrated that the nanohybrid shish-kebab-like crystalline structure was formed in the blends. Due to the hierarchical structure, the PLA/PBAT (90/10) blend prepared by PIF processing at 110 °C and 100 MPa exhibited ultrahigh tensile strength (209.5 MPa), good elongation at break (91.4%), high tensile modulus (2446.7 MPa), and excellent toughness (142.6 MJ/m3), which were much higher than those prepared by an injection-molded pure PLA and PLA-based blend. According to these results, the facile, effective, and practical method employed in this study was able to fabricate high-performance polymeric materials and may be used as a viable alternative to engineering plastics for structural application

Supplemental Material, Revised_Supplementary_Information_20180210 - Enhanced sound insulation and mechanical properties based on inorganic fillers/thermoplastic elastomer composites

<p>Supplemental Material, Revised_Supplementary_Information_20180210 for Enhanced sound insulation and mechanical properties based on inorganic fillers/thermoplastic elastomer composites by Wei Fang, Yanpei Fei, Huanqin Lu, Jiangming Jin, Mingqiang Zhong, Ping Fan, Jintao Yang, Zhengdong Fei, Feng Chen and Tairong Kuang in Journal of Thermoplastic Composite Materials</p

A Simple, Low-Cost, and Green Method for Preparing Strong, Tough, and Ductile Poly(lactic acid) Materials with Good Transparency and Heat Resistance

Notwithstanding that unprecedented progress has been achieved in strengthening and toughening PLA materials, it is still a challenge to find a facile and low-cost way to improve poly(lactic acid) (PLA) strength, toughness, and ductility while maintaining transparency and biodegradability. Herein, strong, tough, transparent, and highly heat-resistant PLA materials with a nacre-like lamellar structure were fabricated via a simple, low-cost and additive-free pressure-driven flow process. PLA powders with a size under 500 μm and heterogeneous size distribution obtained from ball milling and size sieving were used to yield a PLA material with a dense and ordered crystalline structure after pressure-driven flow treatment. The newly formed structured PLA material exhibited exceptional mechanical properties, with tensile strength, elongation at break, impact strength, and tensile toughness reaching 88.9 MPa, 102.5%, 45.1 KJ/m2, and 81.2 MJ/m3, respectively. The refined strength, toughness, and ductility were attributed to more particles undergoing uniform plastic deformation during the pressure-driven flow treatment. The interface between particles in the powder was much larger and more tortuous, and the particles were firmer. Additionally, the newly formed tightly stacked crystal structure consisting of densely and orderly arranged nanosized crystals played an important role in improving the mechanical properties of PLA. Moreover, the newly formed structured PLA materials exhibited enhanced heat resistance and retained good transparency, with a visible light transmission of over 80%. Overall, this work presents a simple and efficient method for fabricating high-performance PLA materials that are strong, tough, ductile, transparent, heat-resistant, and easily recyclable