Effect of Chemical Treatment on Rice Straw Fiber Surface and Properties of Straw/Polylactic Acid Composites

ABSTRACT

In this work, rice straw fibers were modified using NaOH, KBM-403, and tetraethyl orthosilicate (TEOS), and the changes in the surface groups of the straw fibers before and after the modification were analyzed by infrared testing. Straw/polylactic composite were prepared by hot pressing, and the effects of the modifiers used on the properties of these blends were studied by conducting mechanical and thermal performance tests. The results showed that the tensile strength of the straw fiber composites modified by NaOH and KBM-403 increased by 20% and 21.2%, respectively, compared with that of the unmodified composite, whereas the tensile strength of the TEOS-modified fiber did not increase significantly. The flexural strengths of the composites increased by 10.2%, 11.1%, and 13.2%. The impact strength increased by 38.5%, 7.6%, and 7.6%. The results of thermal analysis show that initial and maximum thermal decomposition temperatures of the composite materials increased, indicating that the modified composite materials had a higher thermal stability. These blends are a kind of potential material for structural applications such as interiors, drywell and partitions for furniture.

摘要

本工作使用NaOH、KBM-403和正硅酸四乙酯（TEOS）对稻草纤维进行了改性，并通过红外测试分析了改性前后稻草纤维表面基团的变化. 采用热压法制备了秸秆/聚乳酸复合材料，并通过力学性能和热性能测试，研究了改性剂对共混物性能的影响. 结果表明，NaOH和KBM-403改性的稻草纤维复合材料的拉伸强度分别比未改性的复合材料提高了20%和21.2%，而TEOS改性的纤维的拉伸强度没有显著提高. 复合材料的弯曲强度分别提高了10.2%、11.1%和13.2%. 热分析结果表明，复合材料的初始热分解温度和最高热分解温度分别提高了38.5%、7.6%和7.6%，表明改性后的复合材料具有更高的热稳定性. 这些混合物是一种潜在的结构应用材料，如室内、驾驶舱和家具隔板.

KEYWORDS:

• Rice straw fiber
• bio-composites
• alkali treatment
• silane coupling agent treatment
• sol-gel modification
• mechanical property
• thermal analysis

关键词:

• 稻草纤维
• 生物复合材料
• 碱处理
• 硅烷偶联剂处理
• 溶胶凝胶改性
• 力学性能
• thermal analysis热分析

Highlights

• Preparation of straw fiber composites subjected to various treatments

• FTIR spectroscopy, SEM, EDS, and TG analyses of the modified composites

• Mechanical property analysis in terms of tensile, bending, and flexural strengths

• Explanations regarding the mechanisms responsible for improved strength

Acknowledgements

The work is gratefully supported by Central government guide Anhui Province Science and Technology Development Project (202107d06020014), Anhui Province University Excellent Talent Cultivation Project (gxgnfx2021133), Anhui Provincial Key Laboratory of New Energy Vehicle Light weighting Technology Open Projects (AKL202102), National Innovation and Entrepreneurship Training Program for College Students (202210363046).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author’s contribution

Methodology, Q.Y.; Conceptualization, F.R.; investigation, C.K., H.W. (Hao Wu) and Z.W.; data curation, G.W.; writing-original draft preparation, F.R.; writing-review and editing, H.W. (He Wang); supervision, Z.X.; project administration and funding acquisition, H.W. (Hongjie Wang). All authors have read and agreed to the published version of the manuscript.

Data availability statement

The data are contained within the article.

Sample availability

The samples are available from the authors.

Additional information

Funding

The work was supported by the Central government guide Anhui Province Science and Technology Development Project [202107d06020014Anhui Province University Excellent Talent Cultivation Project [gxgnfx2021133]; Anhui Provincial Key Laboratory of New Energy Vehicle Light Weighting Technology Open Projects [AKL202102]; National Innovation and Entrepreneurship Training Program for College Students [202210363046].