Nonisothermal crystallization behavior and mechanical properties of poly(lactic acid)/ramie fiber biocomposites

Abstract

Poly(lactic acid) (PLA) and PLA/natural fiber composites are considered as environmentally friendly materials and are becoming one of the research hotspots.Many research achievements of PLA and its composites prefer to focus on modification and the macro-properties of composites while there are few works on relationships between processing, structures, and properties. The ramie fiber (RF) reinforced PLA biological composites were prepared and PLA/RF injectionmolded samples were fabricated to investigate effects of RF percentage (0, 5 wt% RF, 10 wt% RF, 15 wt% RF, 20 wt% RF) on PLA crystallization, thermal and mechanical performance by experimental and numerical methods. Experimental and simulated results indicate that the RF serves as a kind of nucleation agent, accelerates the crystallization rate, shortens the half crystallization time of PLA. The degree of crystallinity is up to 16.2% when PLA is with 20 wt% RF. The half crystallization time of PLA with 5 wt% RF composite is reduced by up to 28%. Correspondingly, the tensile strength and Young's modulus of the PLA composites are also improved by the RF without sacrificing thermal stability.

Transparent, Hydrolysable and Flame Retarded Bio-based Epoxy Resins via Catalyst-free Polymerization of Triglycidyl Isocyanurate and Aliphatic Diacids

“…The decomposition of ERs follows a three-stage process, including the decomposition of isocyanurate ring at 300 °C, the pyrolysis of carbon chains and eventually the pyrolysis of carbon residue. The higher second-step decomposition temperature for ER12-60 is understandable due to the longer methylene group [18,31]. As shown in Figure 2c and Table 2, the glass transition temperature (Tg) of ERs increases with the shortening of chain length of DAs, from 45.1 °C for ER12-60 to 64.1 °C for ER08-60.…”

The static and dynamic mechanical properties analysis of ramie/carbon fiber‐reinforced composites

“…It has been widely reported that the residual mechanical properties of the composites will be greatly reduced after impact injury, 18,19 and the influence of residual tensile properties of nonwoven flax fiber‐reinforced composites under different impact energies was demonstrated by Habibi et al 20 Dhakal et al 21 studied the effects of mechanical properties of cannabis/basalt fiber‐reinforced composites after the impact, and the initial stage of the impact caused obvious damage in the form of matrix cracking and fiber fracture, which significantly reduced the residual strength after the impact. Meanwhile, many researchers have done a lot of research on the high‐ and low‐speed impact damage of hybrid fiber composites in recent years 22 . Fabrizio et al 23 studied the damage tolerance under low‐speed impact of flax/carbon intermixed composites.…”

Enhancing flame retardancy of poly(lactic acid) with a novel fully biobased flame retardant synthesized from phytic acid and cytosine

“…[1][2][3][4] Poly(lactic acid) (PLA), an important bioderived, sustainable and biodegradable material, is a promising alternative to traditional petroleum-based polymers owing to its excellent combination property. [5][6][7][8][9] Nevertheless, the flammability of PLA restricts its extensive use, especially in applications near charged products. [10][11][12] In order to expand the application of PLA, many methods have been put forward to improve its flame retardancy.…”

“…The widespread use and improper disposal of plastic products have led to global environmental pollution, so in order to mitigate these negative environmental impacts, increasing efforts are being made to develop biodegradable polymeric materials 1–4 . Poly(lactic acid) (PLA), an important bioderived, sustainable and biodegradable material, is a promising alternative to traditional petroleum‐based polymers owing to its excellent combination property 5–9 . Nevertheless, the flammability of PLA restricts its extensive use, especially in applications near charged products 10–12 .…”