Effects of Extractives on Dimensional Stability, Dynamic Mechanical Properties, Creep, and Stress Relaxation of Rice Straw/High-Density Polyethylene Composites.

Huanbo Wang,Fazhi Lin,Pingping Qiu,Tian Liu

doi:10.3390/polym10101176

Abstract

The removal of rice straw extractives increases the interphase adhesion between rice straw and the high-density polyethylene (HDPE) matrix, while eradicating the inner defects of rice straw/HDPE composites. This study investigated the effect of rice straw extractives removal on the dimensional stability (water uptake and thermal expansion), dynamic mechanical properties, creep, and stress relaxation of rice straw/HDPE composites. Cold water (CW), hot water (HW), and 1% alkaline solution (AL) extraction methods were utilized to remove rice straw extractives. Extracted and unextracted rice straws were mixed with HDPE, maleated polyethylene (MAPE), and Polyethylene wax to prepare composites via extrusion. Removal of rice straw extractives significantly improved the dimensional stability, dynamic mechanical properties, and creep and stress relaxation of rice straw/HDPE composites, with the exception of the thickness swelling of the AL/HDPE and the thermal expansion of the rice straw/HDPE composites. HW/HDPE exhibited the best comprehensive performance.

Highlights

Natural fiber reinforced polymer composites (NFPCs) have been widely utilized in construction, automotive, packaging, window and door frames, furniture, railroad sleepers, gardening items, shelves, aerospace, leisure, and sports industries
Composites decreased decreased overmeasured the entiretemperature measured range. This might caused mobility by the increased over the entire. This might be caused by thebe increased of high-density polyethylene (HDPE)
E0 elastic was closely associated with the Cold water (CW)/HDPE, rice straw (RS)/HDPE

Summary

Introduction

Natural fiber reinforced polymer composites (NFPCs) have been widely utilized in construction, automotive, packaging, window and door frames, furniture, railroad sleepers, gardening items, shelves, aerospace, leisure, and sports industries. Natural fibers have a bright prospect as a substitution of artificial, non-renewable, and undegradable fibers in polymer composites. The weak interfacial adhesion between polar natural fibers and non-polar ones lead to a reduction of stress transfer efficiency from the matrix to the reinforcing fibers. A further drawback of the NFPCs is the increased water absorption due to the hydrophilic natural fibers. Water absorption changes the volume of the fibers within the NFPCs and induces internal stresses [5].

Methods

Results

Conclusion