Crystallization kinetics and morphology of small concentrations of cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) melt-compounded into poly(lactic acid) (PLA) with plasticizer

编号 020023002

推送时间 20200316

研究领域 林产化工 

年份 2020 

类型 期刊 

语种 英语

标题 Crystallization kinetics and morphology of small concentrations of cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) melt-compounded into poly(lactic acid) (PLA) with plasticizer

来源期刊 Polymer

期 第230期

发表时间 20191219

关键词 Poly(lactic acid);  Nucleation;  Nanocellulose;  Avrami kinetics;  Crystallization; 

摘要 In the present study, very small concentrations of CNCs and CNFs were melt-compounded into PLA using a solvent-free process where poly(ethylene glycol) (PEG) was used to disperse the nanoparticles in PLA. As a comparison, the commercial nucleant, talc, was processed similarly into PLA. CNC and CNF were shown to be efficient nucleants for PLA, similar to talc, and conventional Avrami and Lauritzen-Hoffman analysis of the crystallization behavior was performed for isothermal temperatures from 90 °C to 130 °C across all compositions. From the Avrami analysis, the crystallization rate, half-time, and Avrami exponent were calculated and suggested a synergistic effect of nanocellulose and PEG, even at very small concentrations. The crystallization half-time was lower than talc at higher temperatures indicating faster crystallization for samples containing nanocellulose under certain conditions. Analysis of secondary nucleation revealed a decrease in the surface energy for CNC containing samples, further suggesting that, given the enhanced mobility of plasticized PLA, very small concentrations of CNC are effective nucleation agents. Lastly, scanning electron microscopy was used to correlate the crystal morphology of chemically etched samples with the thermal analysis. Coarsening of the microstructure was observed initially with the addition of PEG, and further coarsening was observed upon the addition of nanocellulose.

服务人员 尚玮姣

PDF文件 浏览全文