纤维素纳米晶体/聚苯乙烯复合薄膜的制备及性能研究

Prearation and Properties of Cellulose Nanocrystal/Polystyrene Composite Films

关键词:  纤维素纳米晶体  聚苯乙烯  Pickering乳液  复合材料  力学性能

Key Words:cellulose nanocrystal  polystyrene  Pickering emulsion  composite material  mechanical property

摘要:通过Pickering乳液法一步实现亲水性纤维素纳米晶体（CNC）和疏水性聚苯乙烯（PS）的高效复合，经溶液浇筑成膜与热压耦合制得力学性能优异的CNC/PS复合薄膜。结果表明，尽管CNC的添加会降低PS薄膜的透明度，但当CNC添加量≤10%时，CNC/PS复合薄膜仍能保持良好的透明度。当CNC添加量为8%时，CNC/PS复合乳液中的乳滴尺寸和乳滴分布均一性最佳，此时CNC/PS复合薄膜的力学性能最佳，其拉伸强度为33.8 MPa，远优于纯PS薄膜（18.9 MPa），韧性和杨氏模量分别为408.1 kJ/m³和1.9 GPa，是纯PS薄膜的1.8倍和1.5倍。当CNC添加量增至20%时，CNC/PS复合薄膜出现发白现象，透光率显著下降，但仍具有与纯PS薄膜相当的力学性能（拉伸强度为20.9 MPa，杨氏模量为1.6 GPa）。

Abstract:The high-efficiency composite of hydrophilic cellulose nanocrystal （CNC） and hydrophobic polystyrene （PS） was realized by Pickering emulsion method in one step， and CNC/PS composite films with excellent mechanical properties were prepared by solution casting into film and hot pressing coupling. The results showed that although the addition of CNC could reduce the transparency of pure PS film， when the amount of CNC was lower than 10%， CNC/PS composite films still maintained transparency. When the amount of CNC was 8%， the droplet size and uniformity of droplet distribution in the CNC/PS composite emulsion were the best. At this time， the mechanical properties of CNC/PS composite film were the best. The tensile strength of CNC/PS composite film was 33.8 MPa， which was much higher than that of pure PS film （18.9 MPa）， the toughness and Young’s modulus of it were increased to 408.1 kJ/m³ and 1.9 GPa， which were 1.8 times and 1.5 times of that of pure PS film， respectively. When the amount of CNC increased to 20%， the CNC/PS composite film showed whitening and a significant decrease of light transmittance，but still had comparable mechanical properties with the pure PS film （tensile strength of 20.9 MPa， Young’s modulus of 1.6 GPa）.