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Lisman Suryanegara Antonio Norio Nakagaito Hiroyuki Yano 《Cellulose (London, England)》2010,17(4):771-778
Polylactic acid (PLA) in a crystallized state has mechanical properties at high temperatures superior to PLA in an amorphous state. However, a long annealing time is required to fully crystallize PLA. In this study, microfibrillated cellulose (MFC)-reinforced partially crystallized PLA composites were produced, with the goal of reducing the time required to fabricate PLA parts. A series of PLA/MFC composites at a fiber content of 10 wt% from degree of crystallinity (Xc) 0 to 43% was obtained by annealing at 80 °C. Although the annealing time required to obtain a composite (Xc: 17%) was only around one-seventh of the 20 min needed to fully crystallize neat PLA (Xc: 41%), both materials had comparable rigidity above the glass transition temperature (T g) and creep deformation at around T g. These results showed that partially crystallized PLA/MFC composite can replace fully crystallized neat PLA. 相似文献
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Idris Nor Najhan Hamidon Tuan Sherwyn Abdullah Nor Salmi Suryanegara Lisman Hussin M. Hazwan 《Cellulose (London, England)》2022,29(3):1583-1607
Cellulose - Water pollution via pharmaceutical drugs such as paracetamol has been a highly concerning issue, and effective measures must be taken to treat these aquatic contaminants. Hence, the... 相似文献
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P G Zweipfenning J A Lisman A Y van Haren G R Dijkstra J J Holthuis 《Journal of chromatography. A》1988,456(1):83-91
A method for the determination of nanogram amounts of delta 9-tetrahydrocannabinol (THC) in plasma and serum is described. THC was quantitatively isolated by solid-phase extraction after addition of an aqueous solution of urea and methanol to the sample. The extracts were analysed by high-performance liquid chromatography with electrochemical detection in the oxidizing mode. The detection limit of THC is ca. 100 pg for a signal-to-noise ratio of 3. With this method, levels of 2 ng/ml of THC in plasma can be measured. 相似文献
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Lisman?SuryanegaraEmail author Hiroaki?Okumura Antonio?Norio?Nakagaito Hiroyuki?Yano 《Cellulose (London, England)》2011,18(3):689-698
This study evaluates the effects of nucleants phenylphosphonic acid zinc (PPA-Zn) and talc, mold temperature, and microfibrillated
cellulose (MFC) reinforcement in the acceleration of injection molding cycle of polylactic acid (PLA). PLA was dissolved in
an organic solvent, mixed with nucleant and MFC, and dried compounds were injection molded into molds at temperatures ranging
from 40 °C to 95 °C and holding times from 10 s to 120 s. Our results showed that PPA-Zn is more effective nucleating agent
compared to talc. The addition of 1 wt% PPA-Zn and the mold temperature of 95 °C exhibited the fastest crystallization rates
for the molded PLA, however, at this temperature the parts could not be quickly ejected without distortion. Addition of 10 wt%
MFC increased the stiffness of PLA at high temperatures and allowed ejection of parts without distortion at a holding time
of just 10 s. At this holding time, the crystallinity of the PLA composite was 15.3% but the storage modulus above T
g
was superior to that of fully crystallized neat PLA due to MFC reinforcement, retaining the shape of the molded part during
demolding. The mechanical properties of the composite at room temperature were also higher than those of fully crystallized
neat PLA. 相似文献
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