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Article
Publication date: 20 September 2024

Lijun Chen, Wanting Zhao and Zheqing Gong

The traditional VeoVa10-VAc copolymer latex, which prepared via the emulsion polymerization of the mixed monomers of VAc and VeoVa10, has the poor water resistance and thermal…

Abstract

Purpose

The traditional VeoVa10-VAc copolymer latex, which prepared via the emulsion polymerization of the mixed monomers of VAc and VeoVa10, has the poor water resistance and thermal stability because of the migration of the conventional emulsifier molecules and the low bond energy of C-C bond. The purpose of this work is that the fluorinated monomer is used to modify the latex. The film of the resultant latex has the C-F bond with high bond energy and low surface energy, which can effectively improve the heat resistance and water resistance of the resultant film. In addition, the reactive emulsifier is used to replace the conventional emulsifier. The drawbacks of the conventional emulsifier molecules migrate and desorb can be avoided when the polymer latex is stored, thereby also improving the water resistance.

Design/methodology/approach

The modified VAc-VeoVa10 latex has been successfully synthesized via the semi-continuous seeded emulsion polymerization, which VAc and VeoVa10 is used as the main monomers and HFMA was used as the functional monomer. KPS and reactive surfactants of SE-10 were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy (FTIR). The latex films were tested by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA). The particle size and its distribution of the latex were measured by the nano particle size analyzer.

Findings

The factors that had an influence on the properties of the latex and the film were investigated in detail. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously.

Practical implications

The resultant latex can be used in both the waterborne interior and exterior wall coatings, pickering stabilized waterborne polymer dispersions, polymer powders, environmentally friendly polymer-modified waterproof mortar and other fields, which can be satisfied with the high demand of thermal stability and hydrophobicity.

Originality/value

The modification of poly (VAc-VeoVa10) by reactive surfactant and fluorinated monomer is seldom reported. In this study, the fluorinated poly (VAC-VeoVa) latex is prepared via the reactive surfactants, which VAc and VeoVa10 is used as the main monomers and hexafluorobutyl methacrylate is used as the functional monomer. Potassium persulfate (KPS) and allyl nonyl phenoxy propyl alcohol polyoxyethylene ether ammonium sulfate are used as the initiator and emulsifier, respectively.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 9 July 2024

Lijun Chen, Wanting Zhao and Zheqing Gong

The traditional vinyl ester of neodecanoic acid-vinyl acetate (VeoVa10-VAc) copolymer latex is a linear structure with poor film formation, thus causing solvent resistance and…

Abstract

Purpose

The traditional vinyl ester of neodecanoic acid-vinyl acetate (VeoVa10-VAc) copolymer latex is a linear structure with poor film formation, thus causing solvent resistance and wear resistance of the latex film to be poor. This study aims to investigate the use of cross-linkers in emulsion polymerization to modify the latex. During the course of film formation, the reactive functional groups react to form cross-linkage. The network structure can effectively improve the compactness of the resin, thereby greatly improving the water resistance, solvent resistance and heat resistance of the resultant film. In addition, the reactive emulsifier is used to replace the conventional emulsifier. Thus, the drawbacks of the conventional emulsifier molecules migrate and desorb can be avoided when the polymer latex is stored.

Design/methodology/approach

The cross-linked VAc-VeoVa10 latex has been synthesized with the reactive surfactants, in which VAc and VeoVa10 are used as the main monomers and ethylene glycol dimethacrylate (EGDMA) was used as the cross-linked monomer. Potassium persulfate (KPS) and mixed surfactants of alkyl allyl polyoxyethylene ether ammonium sulfate (JS-20) and allyl nonyl phenol polyoxyethylene ether (ANPEO-10) were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy. The latex films were tested by thermogravimetric analysis, differential scanning calorimetry and contact angle (CA). The particle size and its distribution of the latex were measured by the nano particle size analyzer.

Findings

The factors that had an influence on the properties of the latex and the film were investigated in detail. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously.

Practical implications

The resultant latex can be used in both the waterborne interior and exterior wall coatings, pickering stabilized waterborne polymer dispersions, polymer powders, environmentally friendly polymer-modified waterproof mortar and other fields, which can be satisfied with the high demand of thermal stability and hydrophobicity.

Originality/value

The modification of poly (VAc-VeoVa10) by reactive emulsifier and cross-linker is seldom reported. In this study, the cross-linked poly (VAC-VeoVa) latex is prepared through the reactive surfactants, with VAc and VeoVa10 used as the main monomers and EGDMA used as the cross-linked monomer. KPS and mixed surfactants of JS-20 and ANPEO-10 are used as the initiator and emulsifier, respectively.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 15 August 2022

Wanting Zhao and Lijun Chen

Self-crosslinked long fluorocarbon acrylate polymer latex has good hydrophobic and oleophobicity, weather resistance, aging resistance, stability and other excellent properties…

Abstract

Purpose

Self-crosslinked long fluorocarbon acrylate polymer latex has good hydrophobic and oleophobicity, weather resistance, aging resistance, stability and other excellent properties, which make the polymer be widely used in coatings, dyes, adhesives and other products. The purpose of this study is to prepare self-crosslinked long fluorocarbon acrylate polymer latex via semi-continuous seeded emulsion technology and carry out comparative study on two different cross-linked monomers.

Design/methodology/approach

Methyl methacrylate (MMA) and butyl acrylate (BA) were used as the main monomers, dodecafluoroheptyl methacrylate (DFMA) as the fluoromonomer, hydroxypropyl methacrylate (HPMA) and N-methylol acrylamide (NMA) as cross-linked monomers, and 1-allyloxy-3–(4-nonylphenol)-2-propanol polyoxyethylene (10) ether (ANPEO10) and 1-allyloxy-3–(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate (DNS-86) as compound emulsifiers via the semicontinuous-seeded emulsion polymerization.

Findings

The properties of the polymer emulsions, which are prepared with two different cross-linked monomers, are compared and discussed, and it is concluded that HPMA is more suitable for the preparation of self-crosslinked polymer emulsions. The formula of the polymer latex is ANPEO10: DNS-86 = 1:1, and the mass ratio of the monomers used in the polymer is MMA: BA: DFMA: HPMA = 14.40:14.40:0.60:0.60.

Practical implications

Self-crosslinked long fluorocarbon acrylate polymer latex can be used in many fields such as coatings, dyes, adhesives and other products.

Originality/value

The self-crosslinked long fluorocarbon acrylate polymer latex is prepared by mixing the nonionic emulsifier ANPEO10 and the anionic emulsifier DNS-86 when potassium persulfate is used as the thermal decomposition initiator and the semicontinuous-seeded emulsion technology is adopted and the comparative study on two different cross-linked monomer is carried out, which is not reported in the open literatures.

Article
Publication date: 27 September 2021

Wanting Zhao, Tantan Shao, Xiaolong Chen, Shusen Cao and Lijun Chen

Fluorine materials have received the keen attention of many researchers because of their water repellency and low surface free energy. The purpose of this paper is to prepare…

Abstract

Purpose

Fluorine materials have received the keen attention of many researchers because of their water repellency and low surface free energy. The purpose of this paper is to prepare self-crosslinking fluorocarbon polyacrylate latexes containing different fluorocarbon chain lengths by semi-continuous seeded emulsion polymerization technology.

Design/methodology/approach

Methyl methacrylate (MMA), butyl acrylate (BA), hydroxypropyl methacrylate (HPMA) and fluorine-containing monomers were used as main monomers. The fluorine-containing monomers included hexafluorobutyl methacrylate (HFMA), dodecafluoroheptyl methacrylate (DFMA) and trifluorooctyl methacrylate (TFMA). Potassium persulfate (KPS) was used as thermal decomposition initiator, non-ionic surfactant alkyl alcohol polyoxyethylene (25) ether (DNS-2500) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS) as mixed emulsifier.

Findings

Through optimizing the reaction conditions, the uniform and stable latex is gained. The polymer of structure was characterized by Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA) were tested on latex films. The particle size and distribution range of emulsion were tested with nano particle size analyzer. After comprehensively comparing the latexes and films prepared by HFMA, DFMA and TFMA, the performance of DFMA monomer modified is better.

Originality/value

The self-crosslinking acrylic emulsion is prepared via semi-continuous seeded emulsion polymerization, which methyl methacrylate (MMA), butyl acrylate (BA), hydroxypropyl methacrylate (HPMA) and fluorine-containing monomers were used as main monomers. The fluorine-containing monomers were composed of hexafluorobutyl methacrylate (HFMA), dodecafluoroheptyl methacrylate (DFMA) and trifluorooctyl methacrylate (TFMA). Potassium persulfate (KPS) was used as thermal decomposition initiator, non-ionic surfactant alkyl alcohol polyoxyethylene (25) ether (DNS-2500) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS) as mixed emulsifier. There are two main innovations. One is that the self-crosslinking acrylic emulsion is prepared successfully. The other is that the effects of monomers containing different fluorocarbon chain lengths on polyacrylate, such as monomer conversion rate, coagulation rate, mechanical stability, chemical stability, emulsion particle size and storage stability, are studied in detail.

Details

Pigment & Resin Technology, vol. 51 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Abstract

Details

The Ideas-Informed Society
Type: Book
ISBN: 978-1-83753-013-7

Article
Publication date: 9 March 2020

Wanting Lu and Xiaokang Zhao

The purpose of this paper is to start with the background of the construction of the M-score model, find the variables that can represent the fraud characteristics of Chinese…

Abstract

Purpose

The purpose of this paper is to start with the background of the construction of the M-score model, find the variables that can represent the fraud characteristics of Chinese companies, and use the data of Chinese A-share listed companies to modify the M-score model.

Design/methodology/approach

In this paper, the fraud behavior of Chinese enterprises that M-score cannot detect is summarized as the basis of adding variables. Then, based on the data of Chinese listed companies, a modified M-score model including nine variables is constructed by the logistic regression method based on Wald.

Findings

Based on the original 8 variables of M-score, this paper adds 10 new variables that can represent the fraud characteristics of Chinese listed companies, and finally, constructs a modified M-score model with 9 variables. Results indicated that indexes such as gross profit margin, fixed assets depreciation rate, equity concentration and audit opinion can characterize the financial fraud of Chinese listed companies.

Practical implications

The modified M-score model based on the characteristics of Chinese enterprises’ fraud is more suitable for Chinese market, which can help investors avoid fraud risks, protect their own rights and interests and reduce losses.

Originality/value

Starting from the background of the model, this paper looks for variables that can characterize the characteristics of fraud in Chinese listed companies. Then, subdivides the research samples into specific fiscal years in which fraud occurs, so that the modified M-score model can be more suitable for the Chinese market.

Details

Journal of Financial Crime, vol. 28 no. 2
Type: Research Article
ISSN: 1359-0790

Keywords

Article
Publication date: 15 August 2023

Linchi Kwok and Michael S. Lin

This study aims to assess green food packages’ role in sustaining a restaurant’s curbside pickup service on three stages of consumer experiences: choosing a restaurant, evaluating…

Abstract

Purpose

This study aims to assess green food packages’ role in sustaining a restaurant’s curbside pickup service on three stages of consumer experiences: choosing a restaurant, evaluating their experiences of a recent purchase and weighing their post-consumption behavioral intentions after the recent purchase.

Design/methodology/approach

The service encounters framework and relevant literature guided the development of the questionnaire. A Qualtrics panel data of 314 valid questionnaires were collected and analyzed with choice experience, ordinary least squares regression and PROCESS modeling.

Findings

First, word-of-mouth (WOM) and function encounters significantly influence consumers’ first-time curbside pickup purchasing decisions. Then, service results encounter (besides distributor encounter) most significantly affects consumers’ overall curbside pickup experience. Finally, green food packages increase consumers’ shares of future purchases through their positive WOM intentions and extra efforts of revisiting the restaurant. Consumers’ perceived importance of green restaurant practices strengthens green food packages’ positive impact on extra efforts.

Practical implications

This study provides operational and marketing insights for restaurants to use food packages and sustain their curbside pickup service.

Originality/value

Besides assessing consumers’ evaluations and behavioral intentions for an off-premises restaurant service expected to stay beyond the pandemic, this research uniquely focuses on green food packages, a sustainability issue lacking research attention. The findings add new empirical insights to studies about sustainability and restaurant/food–retail operations.

Details

International Journal of Contemporary Hospitality Management, vol. 36 no. 6
Type: Research Article
ISSN: 0959-6119

Keywords

Article
Publication date: 18 March 2022

Min Zhang, Xiande Zhao, Baofeng Huo and Barbara Flynn

This study aims to examine the relationships between power, relationship commitment and customer integration by replicating and extending Zhao et al. (2008) in China and the USA.

Abstract

Purpose

This study aims to examine the relationships between power, relationship commitment and customer integration by replicating and extending Zhao et al. (2008) in China and the USA.

Design/methodology/approach

This study collects data from 210 manufacturers in China and 202 manufacturers in the USA. In this study, structural equation modelling is used to analyse the data.

Findings

This study finds that normative relationship commitment is positively associated with customer integration and expert and referent power are positively associated with normative relationship commitment in China and the USA. Reward and coercive power are positively associated with instrumental relationship commitment in China, whereas referent power is negatively associated. Referent, legal legitimate and reward power are positively associated with instrumental relationship commitment in the USA, whereas expert and legitimate power are negatively associated.

Originality/value

This study provides empirical evidence on the distinct impacts of different bases of mediated and non-mediated power in China and the USA, contributing to the development of the power-relationship commitment theory. The findings also provide insights into where and when the theory applies. The results can provide guidelines for managers to adjust the use of power to improve relationship commitment and customer integration in China and the USA.

Details

International Journal of Physical Distribution & Logistics Management, vol. 52 no. 3
Type: Research Article
ISSN: 0960-0035

Keywords

Article
Publication date: 13 April 2012

Dawn Langkamp Bolton and Michelle D. Lane

The purpose of this paper is to develop a measurement instrument for individual entrepreneurial orientation to be used to measure the entrepreneurial orientation of students and…

11483

Abstract

Purpose

The purpose of this paper is to develop a measurement instrument for individual entrepreneurial orientation to be used to measure the entrepreneurial orientation of students and other individuals.

Design/methodology/approach

A measure of Individual Entrepreneurial Orientation (IEO) was generated, validated, and then tested on 1,100 university students. The items for the scale were based on the definitions of the five entrepreneurial orientation dimensions presented by Lumpkin and Dess. Final analysis of the IEO items using exploratory factor analysis resulted in reliable and valid measures for three of the dimensions.

Findings

The scale development process for IEO resulted in three distinct factors that demonstrated reliability and validity: innovativeness, risk‐taking, and proactiveness, which statistically correlated with measures of entrepreneurial intention.

Research limitations/implications

The study comprised students at one university in the central southern USA and should be extended to other regions of the country and world, as well as to non‐students, for greater generalisability.

Practical implications

An individual‐level entrepreneurial orientation measurement instrument can be used to assist in entrepreneurship education and in student team and project assignments. It has value as a factor of influence in determining educational training for various decisions such as career choices and business endeavours. IEO also could be used by venture capitalists who are considering supporting business proposals and by individuals who want to assess the strength of their orientation towards entrepreneurship.

Originality/value

The paper contributes to the measurement of entrepreneurial orientation of individuals and can be used to help with student education and business training.

Case study
Publication date: 30 January 2024

Youwei Wang

As an Internet fashion brand, HSTYLE has developed into an Internet enterprise with annual sales of 1.5 billion RMB within 10 years, establishing its position as the top industry…

Abstract

As an Internet fashion brand, HSTYLE has developed into an Internet enterprise with annual sales of 1.5 billion RMB within 10 years, establishing its position as the top industry performer in China. This case studies HSTYLES' innovation in business model and organizational management. HSTYLE's workgroups have achieved the balance of responsibilities and rights in a small team of three members at minimum, while mobilizing the enthusiasm and initiative of the line managers with the support of public service sector. At the same time, HSTYLE enriches its brand style, establishes a fashion cloud platform, and integrates individual and organizational consumers into its existing fashion design, manufacturing and sales system.

Details

FUDAN, vol. no.
Type: Case Study
ISSN: 2632-7635

1 – 10 of over 10000