Chuanxin Feng, Zewen Li and Haosheng Wang
This paper aims to investigate the effects of epoxy resin on the rheological and mechanical properties and water absorption rate of wood flour/high-density polyethylene (HDPE…
Abstract
Purpose
This paper aims to investigate the effects of epoxy resin on the rheological and mechanical properties and water absorption rate of wood flour/high-density polyethylene (HDPE) composites (wood-plastic composite [WPC]).
Design/methodology/approach
The reactive mixing of various epoxy resins with 60 Wt.% wood flour and HDPE was carried out in a twin-screw extruder with a special screw element arrangement. Polyethylene-grafted maleic anhydride (MAPE) was used as a coupling agent to improve the interfacial interaction between wood flour, epoxy resin and HDPE.
Findings
The tensile, flexural and impact properties of the composites increased initially and then decreased with the increasing content of epoxy resin. The complex viscosity decreased with increasing epoxy resin content, but a trend reversal was observed at 8 Wt.% epoxy resin. The epoxy resin-modified wood-HDPE composites chemically coupled by MAPE showed minimal water absorption.
Research limitations/implications
The cured epoxy resins impart high-aspect-ratio and plate-like polymeric fillers, affect the rheological behavior of the WPC and can also be oriented in a flow direction. Epoxy resin has good interaction with the cellulose structure of wood flour because of the polar functional groups within the cellulose.
Practical implications
This method provided a simple and practical solution to improve the performance of WPC.
Originality/value
The WPC modified by epoxy resin in this study had high performance in rheological and mechanical properties, and thus can be widely used for domestic, packaging and automotive applications.
Details
Keywords
This paper aims to feature preparation and characterization of thiokol oligomer functionalized MWCNTs/epoxy nanocomposites using low molecular weight polyamide as curing agent.
Abstract
Purpose
This paper aims to feature preparation and characterization of thiokol oligomer functionalized MWCNTs/epoxy nanocomposites using low molecular weight polyamide as curing agent.
Design/methodology/approach
First, thiokol oligomer functionalized MWCNTs (MWCNTs-TO) were prepared through hydroxylation, silanization and graft modification of MWCNTs. The nanocomposite specimens were fabricated through sonication and cast moulding process. The authors then investigated the impact of MWCNTs-TO content on mechanical and thermal properties of the nanocomposites.
Findings
MWCNTs-TO with grafting ratio of 17.5 Wt.% was synthesized and characterized with X-ray photoelectron spectroscopy, thermal gravimetric analysis, Fourier transform infrared and scanning electron microscopy. The obtained epoxy nanocomposites exhibit improved mechanical properties and thermal stability with MWCNTs-TO added. Moreover, desirable results were obtained at 0.75 Wt.% of MWCNTs-TO loading: the young’s modulus, tensile, flexural and impact strength increased by 24.6,72.8,34.8 and 82.7%, respectively, compared to the neat epoxy. The improvement of mechanical properties is mainly attributed to enhanced interfacial interaction and dispersion between the covalent functionalized MWCNTs and epoxy matrix.
Research limitations/implications
A flexible thiokol oligomer was successfully grafted onto MWCNTs via a mild route. Nanocomposites with excellent interfacial interaction and dispersion between MWCNTs-TO and the epoxy matrix have been successfully fabricated and investigated.
Practical implications
This method provided a mild and practical approach to improve the performance of MWCNTs epoxy nanocomposites.
Originality/value
A flexible thiokol oligomer was successfully covalent grafted onto MWCNTs via a mild route. Nanocomposites with excellent interfacial interaction and dispersion between MWCNTs-TO and the epoxy matrix have been successfully fabricated and investigated.
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Keywords
Juan Wang, Xiongrong Huang, Wei Wang, Haosheng Han, Hongyu Duan, Senlong Yu and Meifang Zhu
The purpose of this study is to determine the tribological behavior and wear mechanism of a polytetrafluoroethylene (PTFE)/polyester (PET) fabric composite for application as a…
Abstract
Purpose
The purpose of this study is to determine the tribological behavior and wear mechanism of a polytetrafluoroethylene (PTFE)/polyester (PET) fabric composite for application as a self-lubricating liner suitable for high-speed and low-load friction conditions.
Design/methodology/approach
The effects of different loads and sliding speeds on the friction coefficients and wear characteristics of the composite were studied using reciprocating friction tests. Scanning electron microscopy, extended depth-of-field microscopy, and energy-dispersive X-ray spectrometry was used to analyze the worn surface morphology, wear depth and elemental content of the lubrication films, respectively.
Findings
The friction coefficient curves of the composites presented a long-term steady wear stage under different sliding conditions. With increasing sliding speed, the friction coefficient and wear depth of the composite slowly increased. The film-forming mechanism of the composite revealed that the PTFE/PET ply yarn on the composite surface formed complete PTFE lubrication films at the initial sliding stage.
Originality/value
The PTFE/PET fabric composite maintained good friction stability and high-speed adaptability, which demonstrates that the composite has broad application prospects as a highly reliable self-lubricating bearing liner with a long lifespan.
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Keywords
Xiaojing Zhang and Yulin Zhang
This study highlights the effect of an inductee's altruism on referral reward programs (RRPs) on an online shopping guide platform to determine the optimal RRP and referral reward…
Abstract
Purpose
This study highlights the effect of an inductee's altruism on referral reward programs (RRPs) on an online shopping guide platform to determine the optimal RRP and referral reward allocation under a Cashback and Referral RRP.
Design/methodology/approach
The authors consider a Stackelberg game with a platform, seller, inductor and inductee, where the inductee's altruism plays a vital role in determining the optimal RRP in equilibrium.
Findings
The authors show that the conditions under which it is optimal to reward the inductor only or reward both inductor and inductee are equal or unequal depending on the degree of the inductee's altruism. Suppose the platform is unable to dynamically decide the commission fee. In that case, the platform may not always be involved in RRPs and will gradually reduce the rewards for inductees as the altruism increases.
Research limitations/implications
This study focuses on a free-to-consumers model where sellers pay membership fees. Thus, this study has limitations regarding other pricing schemes such as a model in which consumers pay a fee while sellers do not or a model in which both types of users pay fees.
Practical implications
This analytical work can help platforms optimize referral reward strategies and referral reward allocation considering the influence of an inductee's altruism.
Originality/value
In a Cashback and Referral RRP on a shopping guide platform, the authors provide applicable conditions for the platform to involve in the RRPs when rewarding an equal bonus for the inductor and inductee first. Further, the authors show the optimal referral reward strategy and referral reward allocation when giving the different bonuses to the inductor and inductee.