磷酸化改性纤维素纳米纤丝复合聚氨酯制备pH响应性形状记忆材料

Preparation of pH-Responsive Shape Memory Composites by Phosphorylated Modified Cellulose Nanofibril and Polyurethane

关键词:  纤维素纳米纤丝  聚氨酯  形状记忆材料  pH响应

Key Words:cellulose nanofiber  polyurethane  shape memory polymers  pH-responsive

摘要:本研究通过在纤维素大分子中引入磷酸基团获得具有pH敏感性的磷酸化纤维素纳米纤丝（Phosphorylation Cellulose Nanofibril，PCNF），然后采用溶剂共混复合聚氨酯（PU）成功制备了具有pH响应能力的形状记忆材料。探究了不同PCNF接枝已内酯材料（PCNF-CL）添加量下PCNF/PU复合材料（SMPU）在酸碱条件下的形状记忆性能。结果表明，在酸碱条件下PCNF-CL与PU分子间能可逆地产生一种氢键缔合，这种作用产生不同的效果可使材料固定和回复形状；当PCNF-CL添加量为10%时，在pH值=1的条件下，该材料可以加工成临时形状，固定率为99.8%，pH值=13时又回复到初始形状，回复率达到99.5%；力学拉伸结果表明，在添加PCNF-CL后SMPU复合材料的力学强度显著提升，且在添加量为1%时拉伸强度达到最大。

Abstract:Phosphorylation of cellulose nanofibril （PCNF） with pH-sensitive was obtained by introducing phosphate groups into cellulose macromolecules. A shape memory material with pH-response was successfully prepared using solvent blending polyurethane （PU）. The shape memory properties of PCNF/PU composite （SMPU） with different PCNF additions under the condition of acid and base were investigated. The results showed that under acid-base conditions， PCNF-CL and PU molecules could reversibly produce a hydrogen bond association， which produced different effects to fix and restore the shape of the material. Under the condition of pH value = 1， the material could be processed into temporary shape with a fixation rate of 99.8%. When pH value was 13， it returned to original shape， and the recovery rate reached 99.5%. The mechanical tensile results showed that the mechanical strength of the SMPU composite material was significantly increased after adding PCNF-CL， and the tensile strength reached the maximum when the addition amount was 1%.