Haoqun Hong

Effect of Wood Flour on the Curing Behavior, Mechanical Properties, and Water Absorption of Natural Rubber/Wood Flour Composites

The preparation of natural rubber/wood flour (NR/WF) composites and the influence of WF content, modification, and particle size on the vulcanizing behavior, mechanical properties, and water absorption of NR/WF composites are described. Results show that the addition of WF into NR delayed the scorching time and vulcanizing time of NR. The appropriate WF contents can improve the mechanical properties of NR. However, the overloading of WF destroys the mechanical properties of NR. The addition of WF increased the water absorption of NR. The silicone couple agents that were used to modify the WF had little effect on the water absorption of NR/WF composites. Decreasing the WF particle size enhanced the water absorption of NR/WF composites because the water-absorbing surface area increased with decreasing WF particle size. The water absorption of sisal-fiber-filled NR-based composites was larger than that of the WF-filled NR-based composites. A useful equation, w=ktn , was inferred from the water absorption results to calculate the water absorption (w) of the NR/WF composites as a function of time (t), where k was a constant concerning the compounds’ character that was primarily determined by the WFs character and n was the power of time that was related to the NRs inherent character, such as cross-linking density, and primarily determined the water absorption rate.

A new kind of water-based nanofluid with a low loading of three-dimensional porous graphene

Abstract In this study, stable water-based heat transfer nanofluid containing a kind of three-dimensional porous graphene (3D PG) has been prepared. For dispersion of 3D PG in water, it is hydrophilic treated by an alkaline method, which is a facile and effective approach in preparing water-soluble graphene by introducing the carboxyl groups (–COOH) as a mild oxidation process using potassium persulfate. The stability and thermal conductive performance of the nanofluid have been investigated with different loading at various temperatures. Experimental results show that the nanofluid can remain highly stability and its enhanced thermal conductivity up to 8–34% can be observed even at lower weight fraction of 0.01–0.07 wt% at room temperature.

Improving the performances of polyethylene/sisal fiber composites by infiltratively compatibilizing the multi-scale interfaces

Sisal fiber (SF) is a good raw material to prepare natural fiber composites (NFCs) by blending it with plastics. However, most NFCs are highly filled with natural fibers in order to decrease the cost of products that causes the weak interfacial compatibilities between the natural fibers and polymers. To successfully prepare a high-performance NFC, the interfacial compatibility is the key problem that should be disposed. In this paper, the graft copolymers of polyethylene (GPE) were used as the infiltrative compatibilizers for SF-filled recycled polyethylene (rPE) composites. How GPE affected the interfacial compatibility and performances of rPE/SF composites were investigated. Results show that the mechanical properties, water resistance and thermal stability of the composites increased with the increase in GPE. The improved interfacial interactions restrained the movement of rPE chains, resulting in the decreasing of crystallinity of the composites. GPE were favorable to improve the rheological properties of the composites. The scanning electron microscopy observation discovered that GPE promoted the formation of infiltrative interfacial interactions that primarily came from the chemical and physical interactions between SF and GPE.

Transform Rice Husk and Recycled Polyethylene into High Performance Composites: Using a Novel Compatibilizer to Infiltratively Enhance the Interfacial Interactions

Rice husks are the fine crop residue used to prepare the industrial wood-like products by melt-blending with polymers. However, most wood-like products are highly filled with natural fibers in order to decrease the cost of the products, as it causes weak interfacial compatibility between the natural fibers and polymers. To successfully prepare a high performance wood-like product, the interfacial compatibility is the key problem that need to be solved. Moreover, the interfacial interactions at the gaps and voids around the natural fibers can enhance the interfacial compatibility of the composites. There is little research focusing on the interfacial interactions at these gaps and voids. In this paper, the multi-monomer graft copolymers of polyethylene (GPE) were used as the compatibilizers for the rice husk (RH) highly filled recycled polyethylene (rPE) composites. How the GPE affected the interfacial compatibility of the composites and the resulting mechanical properties, water resistance, thermal stability and rheological properties of rPE/RH composites were investigated. Results show that GPE could enhance the interfacial interactions of rPE/RH composites by infiltrating into the gaps and voids around RH. The strong interfacial interactions of the composites primarily came from the chemical reactions and physical interactions between RH and GPE. The mechanical properties, water resistance and thermal stability of the composites increased with the increase in GPE loadings. The preferable loadings of GPE were approximately at 8 phr. Meanwhile, GPE could improve the processing properties of the composites.