No abstract

In order to develop an environmentally benign flame retardant for bamboo/ PLA composites (BPC), chitosan (CS) and tannic acid (TA) were used as cationic and anionic polyelectrolyte respectively to stabilize halloysite nanotubes (HNT) on the surface of bamboo fiber (BF) and poly(lactic acid) (PLA). Mechanical performance tests showed that the flexural properties of BPC were moderately enhanced with the addition of HNT, while the incorporation of CS/TA complex (FR) exhibited a slight increase. The results of thermogravimetric analysis demonstrated that CS/TA complex and HNT improved the thermal stability of the BPC synergistically, which increased the char residue. Limiting oxygen index and cone calorimetry tests were used to study the flammability of BPC and the results showed that the addition of CS/TA complex and HNT had a synergistic effect on the flame retardant performance of BPC materials. The macroscopic and microscopic morphological studies confirmed the formation of HNT layer in the matrix of BPC/5FR@5HNT samples, which facilitated more stabile char residue with the best flame retardant performance. K E Y W O R D S biodegradable, biopolymers and renewable polymers, cellulose and other wood products, flame retardance, thermogravimetric analysis 1 | INTRODUCTION Bamboo is well-known as a fast-growing, widely distributed biomass resources. Bamboo fiber (BF) has excellent mechanical properties and can improve the mechanical properties of polymer composites. [1] As an extension of wood plastic composites (WPC), bamboo plastic composites are defined as a new type of general-purpose composite material composed of BF and thermoplastic materials. [2] However, most of commercially used plastics, such as polyethylene, poly(vinyl chloride), polypropylene, and polystyrene all originate from nonrenewable petroleum resources, meanwhile the plastic waste can cause serious pollution to the environment. [3] Recently, the increasing ban on use of non-degradable plastic products is enacting around the world, biodegradable polymer for composites have attracted much attention, especially BF/poly(lactic acid) (PLA)-based composite materials, since they are biodegradable, biocompatible and sustainable in nature. [4] However, BF/PLA composites (BPC) exhibit potential fire hazards in application of interior decoration, due to

Rattan cane is an important forest product only second to timber and bamboo, with higher economic value and ecological benefits. Physical and mechanical properties are more important quality performance indexes, which are highly correlated with the processing and utilization of rattan cane. The present paper describes a study of main physical and mechanical properties in different heights of rattan cane for four rattan species, and also makes a comparison of property for Calamus simplicifolius grown in different sites. The relationship between species, cane position, density and mechanical properties of the rattan in China is also discussed. The results show that the physical and mechanical properties differ among four rattan species, and they follow irregular variation pattern with height. The physicalmechanical properties have no significant difference among species except modulus of elasticity, and the same as the different geographical areas. The basic density and mechanical properties gave a more moderate correlation with quadric equation. This result will provide basic data support for property modification and commercial utilization of rattan resources.

The combination of surface densification and superheated steam treatment is an effective method to improve the mechanical properties and dimensional stability of low-density wood. The objective of the current work is to evaluate the effects of superheated steam treatment on the micromechanical behavior of surface densified wood. The microstructure, chemical composition, cellulose crystalline structure, and micromechanical behavior of surface densified wood under different superheated steam pressures were investigated. Results indicated that both 0.1 MPa and 0.3 MPa superheated steam treatments increased the elastic modulus and hardness of fiber cell walls in surface densified wood. However, the average creep ratio and maximum creep compliance J(50) of surface densified wood under 0.3 MPa decreased by 41.59% and 6.76%, respectively, compared with untreated wood. The improvement of elastic modulus, hardness and creep resistance of surface densified wood treated with superheated steam was associated with the increase of relative crystallinity (CrI) and crystalline size. In addition, 0.3 MPa superheated steam treatment displayed a better effect on the enhancement of the elastic modulus, hardness, and creep resistance of the fiber cell wall than 0.1 MPa superheated steam treatment.

No abstract

No abstract

No abstract

No abstract