Crystallization behavior of poly(L‐lactic acid)‐based ecocomposites prepared with kenaf fiber and rice straw

Abstract

Several composites of poly(L‐lactic acid) (PLLA) with natural fibers (kenaf and rice straw) and pigments have been prepared and analyzed. The study of the thermal behavior has shown a rather important nucleation ability of these fillers for the crystallization of the PLLA component in the composites. Thus, the cooling from the melt of pure PLLA at 10°C/min leads to an almost completely amorphous sample, while a high crystallinity (around 60%) is exhibited by the sample PLLA and rice straw (PLLA‐RS)‐yellow under those conditions. The analysis of the isothermal crystallization from the melt indicates that a maximum rate of crystallization is obtained for all the samples at around 105°C, although the rate is three times faster for samples PLLA and kenaf fiber (PLLA‐KF), PLLA‐KF‐red, and PLLA‐RS, in comparison with pure PLLA. The rate is increased by another factor of three for sample PLLA‐RS‐yellow. The analysis of the melting temperatures and crystallinities as a function of the crystallization temperature shows that there is a break at around 115°C, which seems to be related to the formation of ordered crystals at higher temperatures and disordered ones at lower temperatures. Besides, the natural fibers are environmentally friendly and nonexpensive materials, and the higher crystallization rates of the composites will result in shorter production cycles of end‐use articles. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers

Electrospun nylon fibers for the improvement of mechanical properties and for the control of degradation behavior of poly(lactide)-based composites

“…42,43 Fibers have the same effect on the crystallization behavior of PLA, as noted for kenaf fibers and rice straw, 44 and for CNTs. 45 DSC was used to assess the nucleating ability of electrospun fibers.…”

Does magnesium compromise the high temperature processability of novel biodegradable and bioresorbables PLLA/Mg composites?

“…5, Table 3). This behaviour contrasts with the important nucleation effect of different fillers in the crystallization of PLLA (Pinho et al, 2009;Papageorgiou et al, 2010;Dobreva et al, 2010a;Dobreva et al, 2010b). Heating from the amorphous condition (CR10F10 - Fig.…”

Isothermal Crystallization and Melting Behavior of Composites Composed of Poly(L-lactic Acid) and Poly(glycolic Acid) Fibers

“…Many researches have reported the n of pure PLLA, but the results seemed inconsistent, varying from 2 to 4. [14][15][16]19,[23][24][25][26] This is mainly because the n value is affected by many factors, such as the nucleation density and molecular weight of the PLLA. Generally, n which depends on the nucleation and growth mechanism of the crystallization is used to roughly describe the nucleation mechanism.…”

“…Their results showed that talc, C 60 and montmorillonite can accelerate the crystallization of PLLA. Dobreva et al [16] prepared two PLLA-based ecocomposites containing kenaf fiber and rice straw and investigated the crystallization behavior of their composites. They concluded that the kenaf fiber and rice straw each had an important nucleation ability for the crystallization of PLLA.…”