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Article
Publication date: 4 January 2019

Buqin Xu, Guilong Xu, Hui Qiao, Yun Liang, Jin Yang and Jian Hu

The flammability of poly-acrylate (PA) resin is a major disadvantage in applications that require flame resistance. It has been reported that a flame-retardant PA resin could be…

241

Abstract

Purpose

The flammability of poly-acrylate (PA) resin is a major disadvantage in applications that require flame resistance. It has been reported that a flame-retardant PA resin could be prepared by covalent incorporate phosphorous containing monomer with vinyl group via free radical polymerization, and the prepared modified PA resin is expected to exhibit better flame resistance than those by an additive approach. However, the phosphorus-containing monomers reported previously are made from expensive or toxic materials, and the production procedure is tedious and under harsh reaction conditions, which are not feasible for industrial application. Therefore, the purpose of this paper is the preparation of flame-retardant PA resin modified by epoxy resin phosphorous acid (EPPA) and the study of its flame retardancy.

Design/methodology/approach

EPPA is first prepared by epoxy resin E-51 and phosphorous acid and then used to prepare phosphorous containing PA resin by free radical polymerization. The flame retardancy of the prepared EPPA-modified PA (EPPA-PA) resin is studied.

Findings

The results show that EPPA can graft onto the PA polymer chain by free radical polymerization, the flame retardancy of the EPPA-PA resin increases as the EPPA content increasing. The flame retardancy of EPPA-PA resin prepared reaches 27.8% and can pass the V-0 rating in the UL-94 test when EPPA content is 30.0%. SEM and EDS results indicate that phosphorous element in the EPPA-PA resin shows a condensed-phase flame retardant effect.

Research limitations/implications

The grafting degree of EPPA cannot be accurately tested.

Practical implications

It is expected that the large-scale production of this epoxy resin phosphoric acid modified PA resin will enable practical industrial applications.

Originality/value

This method for synthesis of epoxy resin phosphoric acid modified PA resin is newfrangled.

Details

Pigment & Resin Technology, vol. 48 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 5 September 2016

Wei Li, Guilong Xu, Buqin Xu, Yi Wang, Jin Yang and Jian Hu

The flammability of epoxy resin is a major disadvantage in applications that require flame resistance. Epoxy monomers and hardeners containing flame-retardant elements are…

371

Abstract

Purpose

The flammability of epoxy resin is a major disadvantage in applications that require flame resistance. Epoxy monomers and hardeners containing flame-retardant elements are molecularly incorporated in the resin network are expected to exhibit better flame resistance than those borne on an additive approach. In recent years, because of health and environmental regulation, the use of waterborne coatings has received many attentions. However, waterborne epoxy resin curing agent with excellent flame retardancy has been seldom reported. The paper aims to study the preparation of waterborne P-N-containing epoxy resin curing agent and its performances (P-N – phosphorous and nitrogen).

Design/methodology/approach

Waterborne P-N-containing epoxy curing agent was prepared in this study using reactive flame retardant 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-xa-10-phosphaphenanthrene-10-oxide, liquid epoxy resin, triethylenetetramine and butyl glycidyl ether at the mole ratio of 1.0:2.0:2.0:2.0.

Findings

The results show that the epoxy thermoset from the prepared P-N-containing curing agent presents good flame retardancy and can pass the V-1 rating, and the cured epoxy thermoset film presents excellent performances such as water resistance, adhesion, impact resistance and pencil hardness. This study provides useful suggestions for the application of the water-borne flame retardancy epoxy resins in coating industry.

Research limitations/implications

Each step of products during the preparation of waterborne P-N-containing epoxy curing agent cannot be accurately tested.

Originality/value

This method for synthesis of waterborne P-N-containing epoxy curing agent is novel and could be used for various applications in epoxy coating industry.

Details

Pigment & Resin Technology, vol. 45 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 4 December 2019

Xinyue Liang, Hui Qiao, Guilong Xu, Yanchong Zhang, Yun Liang and Jian Hu

The flammability of poly-acrylate (PA) resin is a major disadvantage in applications that require flame resistance. Many studies, including the authors’ previous study, have…

151

Abstract

Purpose

The flammability of poly-acrylate (PA) resin is a major disadvantage in applications that require flame resistance. Many studies, including the authors’ previous study, have proved that covalent-incorporated phosphorous-containing (P-containing) monomer onto the PA resin can exhibit better flame resistance than that by an additive approach. However, other properties such as thermal stability, coating properties are still deteriorated. To further improve the flame-retardancy and other comprehensive properties of the P-containing PA resin, in this study, melamine formaldehyde(MF) resin was used not only as a curing agent to enhance the coating properties of the PA resin, but also as a nitrogen-containing (N-containing) resin to form a P-N synergistic effect and therefore further improve its flame retardancy.

Design/methodology/approach

Epoxy resin phosphorous acid-modified (EPPA-modified) PA (EPPA-PA) resin was first prepared and then using MF resin as curing agent. The flame retardancy of the cured resin was tested by the limiting oxygen index (LOI) and UL 94 methods. The thermal stability of the cured resin was studied by TGA. The coating technology such as adhesion property, pencil hardness and anti-solvent properties were characterized according to methods of International Standards ISO2409-1992, ISO 15184-1998 and ISO-15184-2012, respectively. The micro-char morphology of the char residue was observed by SEM.

Findings

The results showed that by using MF resin as curing agent has provided the PA resin with excellent coating properties and thermal stability, but also gave a P-N synergistic effect which has greatly enhanced the flame retardancy of the cured resin. The cured resin system containing only 1.7 Wt.% P content and 5.3 Wt.% N content can reach a LOI of 26.9 per cent and pass the V-0 rating in the UL-94 test.

Research limitations/implications

This resin system releases formaldehyde due to the MF resin.

Practical implications

It is expected that the large-scale production of this EPPA-PA resin cured by MF resin system will enable practical industrial applications.

Originality/value

This method for the synthesis of a P- and N-containing PA resin system is newfangled.

Details

Pigment & Resin Technology, vol. 49 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 5 March 2018

Feng Zhang, Jianjun Yang, Zhi Xu and Guilong Zhu

Focusing on internal corporate governance, the purpose of this paper is to apply the shareholder activism perspective to consider how large shareholder participation behaviors…

888

Abstract

Purpose

Focusing on internal corporate governance, the purpose of this paper is to apply the shareholder activism perspective to consider how large shareholder participation behaviors might influence firm innovation performance. Specifically, “confrontationally strategic intervention” and “cooperatively strategic consensus” participation behaviors are examined and hypothesized to have different effects on managers’ risk-taking and firm innovation performance.

Design/methodology/approach

Drawing on 182 Chinese firm samples, this paper applies hierarchical ordinary least-squares regression analysis to test the proposed hypotheses.

Findings

The results show that strategic intervention was negatively associated with managers’ risk-taking and firm innovation performance, while strategic consensus positively affected managers’ risk-taking and firm innovation performance. Moreover, managers’ risk-taking fully mediated the influence of strategic intervention on firm innovation performance, whereas it partially mediated the influence of strategic consensus on firm innovation performance.

Originality/value

The study extends research on shareholder participation by construing that large shareholders’ participation behaviors can significantly influence managers’ risk-taking and corporate innovation performance, further deepening the understanding of the influences of large shareholders on the firm-level outcomes. The theoretical and practical implications of this finding are also discussed.

Details

Nankai Business Review International, vol. 9 no. 1
Type: Research Article
ISSN: 2040-8749

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Article
Publication date: 6 August 2024

Guilong Li and Gulizhaer Aisaiti

The purpose of this paper is to identify the dimensions and formation mechanisms of brand value on social media platforms within the prosumption logic based on the theory of value…

135

Abstract

Purpose

The purpose of this paper is to identify the dimensions and formation mechanisms of brand value on social media platforms within the prosumption logic based on the theory of value co-creation. By adopting a process-oriented mindset, this study deconstructs and applies the prosumption theory and the theory of value co-creation in the field of social media, thereby addressing the insufficiencies of previous research that focused primarily on the subject mindset. It offers reference ideas for social media brand managers to attract prosumers to engage in value co-creation.

Design/methodology/approach

The crawler technology and grounded theoretical method were adopted in this research paper.

Findings

Based on the logic of prosumption and the theory of value co-creation, the research finds that the brand value of social media platforms is composed of seven dimensions. The dimensions include brand recognition, brand perception quality, brand experience, brand value-in-use, brand relationship quality, brand loyalty and brand co-creation behavior. From the perspective of prosumption logic, the formation of brand value on social media platforms is a gradual accumulation process. This process involves prosumers participating in prosumption activities, progressing through several stages. Initially, it starts with “prosumption conditions”, which include brand recognition, brand perception quality and brand experience. It then moves to “prosumption processes,” characterized by brand value-in-use and brand relationship quality. Finally, it culminates in “prosumption outcomes,” represented by brand loyalty and brand co-creation behavior. From the perspective of value creation, the formation of brand value on social media platforms is a closed-loop process that includes “brand value identification and empowerment—brand value acquisition and transformation—brand value co-creation and relationship upgradation—brand value co-creation and stability—brand value feedback and iteration.”

Originality/value

The findings contribute to expanding prosumption and co-creation theory and enriching the prosumption logic frame. Meanwhile, it is conducive to encouraging prosumers to participate in the platform’s prosumption activities and jointly creating the brand value of the social media platform. This paper interprets prosumption through the lens of the value co-creation process.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 27 July 2023

Mianzhi Yang, Qing Hui, Qingru Yang, Mengwei Fan and Xin Li

China has recently introduced a new audit law that aims to increase the scope of audit supervision and raise the standards for preventing risks in auditing national public…

241

Abstract

Purpose

China has recently introduced a new audit law that aims to increase the scope of audit supervision and raise the standards for preventing risks in auditing national public projects. This paper presents a systematic research study on the causes of audit risks in national public projects and discusses the process by which these causes contribute to the emergence of such risks. Furthermore, the paper investigates the core risk sources in various types of national construction project audit. This paper aims to provide theoretical support for auditors of national construction projects in risk avoidance when conducting audits.

Design/methodology/approach

In this study, the authors carefully selected five national public audit projects from China and performed a comprehensive analysis of 85 relevant audit documentation. The textual analysis was conducted using Nvivo12 software, and the grounded theory approach was adopted for generalization purposes.

Findings

Based on the research results, the findings suggest that there are five key causes contributing to the audit risk of national construction projects: professional competence, risk awareness, management capacity, level of attention and deliberate fraud. The most critical factor identified is management capability, with 59.93% of the data supporting this view. This conclusion was based on an analysis of state-owned enterprises, administrative organs and public institutions. Building upon this, a framework titled “the mechanism of audit risk factors with management capability as the core” was constructed.

Originality/value

This paper employs qualitative analysis methods to examine national construction projects in China, contributing new literature to the theoretical study of audit risk management. The article also provides practical recommendations for auditors on how to mitigate audit risks and improve the quality of audit services in national project governance.

Details

Engineering, Construction and Architectural Management, vol. 32 no. 1
Type: Research Article
ISSN: 0969-9988

Keywords

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