Xiaofeng Zhang, Shuangying Wei and Zhenhua Gao
The purpose of this paper is to investigate the effects of multi-hydroxymethylated phenol (MHMP) on the properties of moisture-curing polyurethane (PU) resin, especially on the…
Abstract
Purpose
The purpose of this paper is to investigate the effects of multi-hydroxymethylated phenol (MHMP) on the properties of moisture-curing polyurethane (PU) resin, especially on the heat resistance.
Design/methodology/approach
The MHMPs with various active sites from 2.52 to 3.91 were synthesised and used as a modifier. The bond test (according to the JIS K6806-2003 standard) and thermogravimetric analysis (TGA) were used, respectively, to characterise the bond durability and heat resistance of MHMP-modified PU resin.
Findings
The MHMP with various F/P mole ratios had great effects on the properties of resultant PU resins. The increase of active sites of MHMP can improve the water resistance of resin due to the more cross-linking densities, while the decrease of active sites of MHMP can improve heat resistance of resin because more stable benzene ring introduced into the PU backbone.
Research limitations/implications
In cases where heat resistance of the PU resin is of primary concern, the use of MHMP with fewer active sites or a lower F/P ratio is recommended. In other cases where bond durability is focussed, the modifier MHMP shall be synthesised with higher F/P ratio.
Practical implications
MHMP as a modifier can be used to improve the heat resistance of PU resin.
Originality/value
The MHMPs with various hydroxymethyl groups were synthesised and used as modifier of moisture-curing PU resins to improve their heat resistance.
Details
Keywords
Guangjin Chen, Peng Lu, Zeyan Lin and Na Song
This paper aims to introduce the history and major achievement of the Chinese private enterprise survey (CPES), which is one of the most enduring large-scale nationwide sample…
Abstract
Purpose
This paper aims to introduce the history and major achievement of the Chinese private enterprise survey (CPES), which is one of the most enduring large-scale nationwide sample surveys in China, providing important micro firm-level data for understanding and studying the development of Chinese enterprises and entrepreneurs over the past 26 years.
Design/methodology/approach
The main body of this paper is based on a bibliometric analysis of all literature using CPES until 2017.
Findings
This paper discusses problems that users may encounter during data mining. By doing so, it can assist other researchers to get a better understanding of what has been done (e.g. journals, topics, scholars and institutions) and do their research in a more targeted way.
Research limitations/implications
As members of the survey project team, the authors also take a prospect of the future data design and use, as well as offer some suggestions about how to use the CPES data to improve high-quality development and business environment evaluation in China.
Originality/value
This paper is the first to provide an overall picture of academic papers in China and abroad that have used the CPES data.