Polymer grafting on cellulose nanocrystals initiated by ceric ammonium nitrate: is it feasible under acid-free conditions?,Green Chemistry

当前位置： X-MOL 学术 › Green Chem. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Polymer grafting on cellulose nanocrystals initiated by ceric ammonium nitrate: is it feasible under acid-free conditions?
Green Chemistry ( IF 9.3 ) Pub Date : 2021-09-30 , DOI: 10.1039/d1gc03142b
Yunxiao Liu _{1,

2} , Yunjie Lu _{1,

2} , Hui Zhang _{1,

2} , Xinran Liu _{1,

2} , Zhengqing Kong _{1,

2} , Lijuan Zhou _{1,

2} , Heng Liu _{1,

2} , Jianming Zhang _{1,

2}

Affiliation

It is of great significance to tailor the physicochemical properties of cellulose nanocrystals (CNCs) for broadening their application fields. Grafting polymerization initiated by cerium ammonium nitrate (CAN) in aqueous medium is a facile and efficient surface modification strategy for CNCs. However, CAN is generally used under strong acidic conditions to prevent hydrolysis; strong acids cause severe environmental problems and limit the monomer species of the candidate. Herein, an acid-free polymer grafting modification method initiated by CAN for carboxylated CNCs (CCNCs) was reported. For CCNCs, a high monomer conversion rate (>80%) and grafting yield (>200%) were obtained even at pH=7 when methyl methacrylate (MMA) was used as the monomer. It is worth noting that the time-consuming dialysis process for CNCs was not required before the grafting reaction, and the CNCs-g-PMMA can be “self-purified” due to its spontaneous precipitation from water. Moreover, the initiator's consumption in this system is very low (1.82 mmol L⁻¹) compared with previously reported values. By investigating the interaction between CAN and CCNCs and the effect of CCNCs on the hydrolysis of CAN, it is revealed that a CCNC complex with Ce⁴⁺ acts as the “macromolecular initiator” to initiate the grafting polymerization under acid-free conditions. This work overcomes the limitation of strong acidic conditions for the polymer grafting modification of CNCs initiated by CAN and is conducive to the industrial production of polymer-grafted CNCs under environmentally friendly conditions.

中文翻译：

由硝酸铈铵引发的纤维素纳米晶体上的聚合物接枝：在无酸条件下是否可行？

调整纤维素纳米晶体（CNCs）的理化性质对于拓宽其应用领域具有重要意义。在水性介质中由硝酸铈铵 (CAN) 引发的接枝聚合是 CNC 的一种简便有效的表面改性策略。但CAN一般在强酸性条件下使用，以防止水解；强酸会导致严重的环境问题并限制候选单体的种类。在此，报道了一种由 CAN 引发的用于羧化 CNCs (CCNCs) 的无酸聚合物接枝改性方法。对于 CCNCs，当使用甲基丙烯酸甲酯 (MMA) 作为单体时，即使在 pH=7 的情况下也能获得高单体转化率 (>80%) 和接枝产率 (>200%)。g- PMMA 可以“自净化”，因为它会从水中自发沉淀。此外，与之前报道的值相比，该系统中引发剂的消耗量非常低（1.82 mmol L ^-1）。通过研究CAN和CCNCs之间的相互作用以及CCNCs对CAN水解的影响，揭示了CCNC与Ce ⁴⁺配合物作为“大分子引发剂”在无酸条件下引发接枝聚合。该工作克服了CAN引发的CNCs聚合物接枝改性强酸性条件的限制，有利于环境友好条件下聚合物接枝CNCs的工业化生产。

更新日期：2021-10-13

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南