Green and efficient synthesis of dispersible cellulose nanocrystals in biobased polyesters for engineering applications
Green and efficient synthesis of dispersible cellulose nanocrystals in biobased polyesters for engineering applications
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DOI：
10.1021/acssuschemeng.5b01611
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发表时间：
2016-04
影响因子：
8.4
通讯作者：
Stephen Spinella;C. Samuel;J. Raquez;S. McCallum;R. Gross;P. Dubois
中科院分区：
文献类型：
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作者：
Stephen Spinella;C. Samuel;J. Raquez;S. McCallum;R. Gross;P. Dubois
尽管纤维素纳米晶体（CNCs）具有天然丰度高、固有的生物可降解性和高模量等吸引人的特性，但在熔融加工过程中，当暴露在高温下时，CNCs往往会降解和聚集。在本工作中，用PMMA修饰cnc表面，以利用熔融共混时与包括PLLA在内的各种生物基聚合物的混相性。重点研究了两种不同的氧化还原引发剂：Fe2+/H2O2 （Fenton试剂）和硝酸铈铵（CAN）在水介质中的接枝技术。通过重量分析、FTIR、CP-MAS 13C NMR和悬浮液试验验证了CNC-g-PMMA的成功合成。以CAN为氧化还原引发剂，接枝效率高达77%。增加CNC表面的PMMA含量可以提高CNC的热稳定性。由于PMMA在水中接枝，改性的cnc被发现在PMMA网络中预分散。然后通过熔融共混法制备PLLA/CNC纳米复合材料（....）
Despite attractive properties of cellulose nanocrystals (CNCs) such as high natural abundance, inherent biodegradability and high modulus, CNCs tend to degrade and aggregate when exposed to high temperatures during melt processing. In the present work, the surface of CNCs was modified with PMMA to take advantage of the miscibility with various biobased polymers including PLLA when melt-blended. Particular attention was paid to grafting techniques in water medium using two different redox initiators: Fe2+/H2O2 (Fenton’s reagent) and ceric ammonium nitrate (CAN). The successful synthesis of CNC-g-PMMA was verified by gravimetric analysis, FTIR, CP-MAS 13C NMR and suspension tests. A high grafting efficiency of 77% was achieved using CAN as the redox initiator. Increasing the PMMA content on CNC surfaces led to higher CNC thermal stability. As a consequence of PMMA grafting in water, modified CNCs were found to be predispersed in a PMMA network. PLLA/CNC nanocomposites were then prepared by melt-blending, i....