纳米纤维素乳化苯乙烯-丙烯酸酯共聚物的制备及性能研究

Study on the Preparation and Properties of Styrene-acrylate Copolymer Emulsified by Nanocellulose

关键词:  纳米纤维素  苯乙烯-丙烯酸酯共聚物  植物纤维  Pickering乳液

Key Words:nanocellulose  styrene-acrylic copolymer  plant fiber  Pickering emulsion

摘要:本研究分别使用纤维素纳米纤丝（CNF）和纤维素纳米晶体（CNC）乳化苯乙烯-丙烯酸酯（SA）单体，以过硫酸铵（APS）为引发剂，通过自由基聚合得到共聚物PSA，并对其各项性能及力学性能增强机理进行研究。结果表明，纳米纤维素在PSA的制备过程中发挥了界面活性剂和功能性填料的双重作用。其中，CNF-PSA乳液稳定性强但黏度较高，CNC-PSA乳液则兼具高稳定性和低黏度的特性。由CNF、CNC和十二烷基硫酸钠（SDS）乳化后聚合得到的PSA共聚物转化率分别为76.32%、78.28%和82.62%。红外光谱和热重分析结果显示CNF和CNC在固化过程中被保留在涂层中，并形成氢键结合。拉伸测试结果表明，CNF-PSA、CNC-PSA和SDS-PSA膜的抗拉强度分别为8.14、6.91和1.09 MPa，其中，CNF-PSA膜的弹性模量达到130.3 MPa，为SDS-PSA膜的652倍。

Abstract:In this study， cellulose nanofibrils （CNF） and cellulose nanocrystal （CNC） were used to emulsify styrene-acrylate （SA） monomers，respectively. The copolymers PSA were obtained with ammonium persulfate（APS）as initiator by free radical polymerization，and its properties and mechanical properties enhancement mechanism were studied.The results showed that nanocellulose played the dual role of surfactant and functional filler in the preparation of PSA，CNF-PSA emulsion had strong stability but high viscosity， while CNC-PSA emulsion had both high stability and low viscosity. The conversion of PSA emulsified with CNF，CNC and sodium dodecyl sulfate（SDS）were 76.32%，78.28%，and 82.62%，respectively. In addition，the FT-IR and thermogravimetric analysis showed that CNF and CNC were re-tained in the coating during the curing process. The tensile strength of CNF-PSA，CNC-PSA and SDS-PSA films were 8.14，6.91，and 1.09 MPa，respectively. The elastic modulus of CNF-PSA film was 130.3 MPa， 652 times that of SDS-PSA film.