Hydrophobization of cellulose oxalate using oleic acid in a catalyst-free esterification suitable for preparing reinforcement in polymeric composites

Tianxiao Huang; Kloce Dongfang Li; Monica Ek

doi:10.1016/j.carbpol.2021.117615

Hydrophobization of cellulose oxalate using oleic acid in a catalyst-free esterification suitable for preparing reinforcement in polymeric composites

Carbohydr Polym. 2021 Apr 1:257:117615. doi: 10.1016/j.carbpol.2021.117615. Epub 2021 Jan 8.

Authors

Tianxiao Huang¹, Kloce Dongfang Li², Monica Ek³

Affiliations

¹ Department of Fiber and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology. Teknikringen 56-58, SE-10044 Stockholm, Sweden. Electronic address: tiahuang@kth.se.
² FineCell Sweden AB, Teknikringen 7, SE-58330 Linköping, Sweden. Electronic address: kloce.dongfang@finecell.se.
³ Department of Fiber and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology. Teknikringen 56-58, SE-10044 Stockholm, Sweden. Electronic address: monicaek@kth.se.

PMID: 33541644
DOI: 10.1016/j.carbpol.2021.117615

Abstract

It is common practice to use cellulose as reinforcement and fatty acid as compatibilizer in the preparation of polymeric composites. However, the used catalysts (e.g., pyridine) are usually toxic and should be avoided. In this study, a new type of microcellulose - cellulose oxalate (COX) was chosen as reinforcement to be reacted with oleic acid to prepare hydrophobic fillers in a catalyst-free esterification for different times. For comparison, microcrystalline cellulose (MCC) was also selected. The success of esterification of COX and oleic acid was confirmed but little esterification occurred when MCC was used. After reacting COX with oleic acid for 18 and 48 h, the products showed stable water contact angles of about 130°. Composites of polypropylene with COX or MCC were prepared. Tensile tests showed that for a given reaction time, the COX-based composites exhibited higher values of both Young's modulus and tensile strength than those of MCC-based composites.

Keywords: Catalyst-free; Cellulose oxalate; Composite; Esterification; Polypropylene; Tensile properties.