The effect of polyurethane-isophorone microcapsules on self-healing properties of an automotive clearcoat

2016 ◽  
Vol 45 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Pooneh Kardar

Purpose – The purpose of this work was to prepare a catalyst-free microcapsules as self-healing agent in an automotive clearcoat to improve the scratch resistance of coatings. Design/methodology/approach – In this research, microcapsule with isophorone diisocyanate (IDPI) core and polyurethane shell were prepared and used in self-healing coatings. Microcapsules synthesised were characterised by thermal gravimeter and infrared spectra. The microcapsules were dispersed in an acrylic-melamine clearcoat, and the scratch resistance was evaluated. Findings – The triplex product and the formed polyurethane bonds were confirmed by thermal gravimeter and infrared spectra. In addition, smooth spherical particles with a diameter of 1.5 to 1.7 micronmeters were observed by a scanning electron microscope. The microcapsules dispersed in an acrylic-melamine clearcoat increased the scratch resistance of coatings. Also, the self-healing feature of those coatings was proved. Research limitations/implications – The size of microcapsules can affect its dispersion in the clearcoat and consequently affect the properties of the cured films. Practical implications – The self-healing coatings are interested for many industries such as building and automotive industries. The reported data can be used by the formulators working in the R & D departments. Social implications – Self-healing systems are considered as one of the smart coatings. Therefore, the developing of its knowledge can help to extend its usage to different applications. Originality/value – The application of microcapsules in the coating as healing agents is a great challenge, which has been hardly investigated so far. In the current research, the effect of polyurethane-IDPI microcapsules in an automotive clearcoat as a self-healing coating was investigated.

2019 ◽  
Vol 48 (5) ◽  
pp. 404-408
Author(s):  
Pooneh Kardar ◽  
Reza Amini

Purpose The purpose of this study is to evaluate the possibility of using titanium dioxide coating in the field of architectural heritage. Design/methodology/approach In this research, a titanium dioxide coating was prepared and then applied to the travertine stone surfaces. The nature of the coating was determined through various observations and analyses. Moreover, the effect of photocatalytic self-cleaning was evaluated using an organic dye (Rhodamine B). Findings The results of XRD, DLS and SEM confirmed the formation of small anatase crystals. The hydrophilic behavior on the surface was observed by coatings based on titanium dioxide. Research limitations/implications The self-cleaning ability of titanium dioxide is due to the synergistic effect of its optical inductive property, which is activated with sunlight. Practical implications The self-cleaning coatings are interested for many industries. The reported data can be used by the formulators working in the research and development departments. Social implications Self-cleaning systems are considered as smart coatings. Therefore, the developing of its knowledge can help to extend its usage to different applications. Originality/value The application of titanium dioxide coating in the field of architectural heritage is a great challenge. Therefore, in this research, a titanium dioxide coating was prepared by sol-gel method and then applied on travertine surfaces and its properties were studied.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fatemeh Narenji Thani ◽  
Ebrahim Mazari ◽  
Somaye Asadi ◽  
Maryam Mashayekhikhi

PurposeConsidering innovation and its improvement as an essential strategy to enable organizations to continue their lives in the new competitive environment leads to a focus on employees' self-development as a factor that affects human resource agility (HRA) and the tendency toward organizational innovation. Consequently, the purpose of the study was to explain the impact of self-development on the tendency toward organizational innovation with the role of the mediator, HRA in higher education institutions as one of the most important and vital organizations in any society.Design/methodology/approachThe study was an applicable one with the quantitative approach using the descriptive–correlative method. The population consisted of 477 nonacademic employees of Kharazmi University among whom 214 ones were selected as the sample group, using a simple random sampling technique. Data were collected through the self-development, HRA and the tendency toward organizational innovation questionnaires and then analyzed using the structural equation modeling approach.FindingsThe study findings revealed a positive impact of self-development on the HRA (γ = 0/79) and HRA on the tendency toward organizational innovation (β = 0/6). Also, self-development with mediating HRA impacts the tendency toward organizational innovation (β = 0/58). Finally, self-development had no direct impact on the tendency toward organizational innovation.Research limitations/implicationsTaking the circumstances of doing this research into consideration, if there were the opportunity to do the research on the staffs of more than one university simultaneously and categorize the university staff into executives, managers and experts, more favorable results could be achieved. Also, considering group and organizational factors with the attention to the self-development approach and its factors would provide more awareness-training information on the higher education system in Iran. For future researches, both the individual and group factors are suggested to be surveyed and compared, to assess the weight and impact of these factors all together and to provide an adequate clarification of the role of the group and the organization. Finally, in future studies, it is also recommended that a qualitative approach be used to reach deeper clarifications on the aspects of these variables in the context of higher education.Practical implicationsThese findings have major practical implications concerning the higher educational settings. The findings of this study must give significant and practical insights for policymakers of universities and other higher education stakeholders, as well as recommendations to the academic community for further research in this area. First, they should recognize that nonacademic staff members are professional employees who contribute to improving organizational innovation. Higher education must focus on designing and implementing successful mechanisms and a well-planned self-development program that can help and promote the self-development approach among all staff. If the above-mentioned programs are designed based on the employees' needs analysis, they will get trained in a way to enhance mental and behavioral flexibility. The programs with such an approach can result in the proactive, adaptive, resilient behavior and agility of HR.Originality/valueThe model for this study has integrated and prioritized the key innovation drivers that would help universities design, adopt and implement policies and practices that facilitate and encourage improvements and adaptation to a fast-paced environment. Furthermore, the convincing reason for the significance of the current research is that although several types of research have been carried out on each of these three variables in different contexts separately, very few studies, like this, have directly examined the correlation between these three variables among the non-academic staff in higher education institutes. So, given the importance of the issue and rare availability of evidence in this regard, the authors were intrigued to discover whether the self-development through the mediation of HRA could reinforce and strengthen the tendency toward organizational innovation and whether HRA could be an appropriate mediator of the relationship between self-development and the tendency toward organizational innovation among the nonacademic staff of Kharazmi University as one of the most prestigious and celebrated universities in Iran.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Raj Kumar Pittala ◽  
Satish Ben B. ◽  
Syam Kumar Chokka ◽  
Niranjan Prasad

Purpose Microcapsule-embedded autonomic healing materials have the ability to repair microcracks when they come into contact with the crack by releasing the healing agent. The microcapsules with specific shape and thickness effect in releasing healing agent to the cracked surfaces. Thus, the purpose of this paper is to know the load bearing capacity of the self-healing microcapsules and the stresses developed in the material. Design/methodology/approach In the present study, self-healing microcapsule is modelled and integrated with the polymer matrix composite. The aim of the present study is to investigate failure criteria of Poly (methyl methacrylate) microcapsules by varying the shell thickness, capsule diameter and loading conditions. The strength of the capsule is evaluated by keeping the shell thickness as constant and varying the capsule diameter. Uniformly distributed pressure loads were applied on the capsule-reinforced polymer matrix composite to assess the failure strength of capsules and composite. Findings It is observed from the results that the load required to break the capsules is increasing with the increase in capsule diameter. The failure strength of microcapsule with 100 µm diameter and 5 µm thickness is observed as 255 MPa. For an applied load range of 40–160 N/mm2 on the capsules embedded composite, the maximum stress developed in the capsules is observed as 308 MPa. Originality/value Failure strengths of microcapsules and stresses developed in the microcapsule-reinforced polymer composites were evaluated.


2018 ◽  
Vol 9 (6) ◽  
pp. 723-736 ◽  
Author(s):  
Elisa Calabrese ◽  
Pasquale Longo ◽  
Carlo Naddeo ◽  
Annaluisa Mariconda ◽  
Luigi Vertuccio ◽  
...  

PurposeThe purpose of this paper is to highlight the relevant role of the stereochemistry of two Ruthenium catalysts on the self-healing efficiency of aeronautical resins.Design/methodology/approachHere, a very detailed evaluation on the stereochemistry of two new ruthenium catalysts evidences the crucial role of the spatial orientation of phenyl groups in the N-heterocyclic carbene ligands in determining the temperature range within the curing cycles is feasible without deactivating the self-healing mechanisms (ring-opening metathesis polymerization reactions) inside the thermosetting resin. The exceptional activity and thermal stability of the HG2MesPhSyncatalyst, with the syn orientation of phenyl groups, highlight the relevant potentiality and the future perspectives of this complex for the activation of the self-healing function in aeronautical resins.FindingsThe HG2MesPhSyncomplex, with the syn orientation of the phenyl groups, is able to activate metathesis reactions within the highly reactive environment of the epoxy thermosetting resins, cured up to 180°C, while the other stereoisomer, with the anti-orientation of the phenyl groups, does not preserve its catalytic activity in these conditions.Originality/valueIn this paper, a comparison between the self-healing functionality of two catalytic systems has been performed, using metathesis tests and FTIR spectroscopy. In the field of the design of catalytic systems for self-healing structural materials, a very relevant result has been found: a slight difference in the molecular stereochemistry plays a key role in the development of self-healing materials for aeronautical and aerospace applications.


2014 ◽  
Vol 31 (8) ◽  
pp. 12-14
Author(s):  
Sue Perry

Purpose – The article aims to convey the experiences of installing an Espresso Book Machine (tm) into Windsor Public Library. It relates how an extremely high-tech, mechanical and new process was received in a very traditional field. Design/methodology/approach – Windsor Public Library acquired an Espresso Book Machine, and built around it a Self-Publishing Centre which included iMacs loaded with software, a scanner, a comfortable area and a dedicated staff member. Findings – The creativity that arose from the Self-Publishing Centre was not limited only to individual, solitary authors who wanted just to produce their own works. A network of like-minded people formed to give encouragement and support developed, increasing the opportunities for elevating literacy in our community. Research limitations/implications – Limitations are obviously that we are one small community enjoying the benefits of this machine. It is impossible to predict if other communities and geographic locations would enjoy the same success. Practical implications – Practical implications are that even with the advancing tide of ebooks and non-print matter, patrons are still very eager to consume and produce printed materials. Social implications – The technological marvels of the high-tech gear that have been installed would be lost without the people forming communities around the technology. Originality/value – The results of installing the Self-Publishing Centre were very different from what we anticipated. The products and community established here are as awe-inspiring as the machine at the heart of the Centre.


2019 ◽  
Vol 810 ◽  
pp. 119-124
Author(s):  
Wataru Nakao ◽  
Taira Hayakawa ◽  
Tesuro Yanaseko ◽  
Shingo Ozaki

The availability of TiC healing agent has been evaluated in low temperature self-healing behavior of Al2O3 based self-healing ceramics. For this purpose, some technical issues to actualize the advanced fiber-reinforced self-healing ceramics containing TiC based interlayer as healing agent were discussed. Especially, the mechanical matching between the matrix and the interlayer was focused. Moreover, the self-healing behavior of the advanced shFRC containing the optimized TiC based healing agent was investigated. As a result, 30 vol% TiC-70 vol% Al2O3 interlayer was confirmed to be the optimized healing agent in the self-healing ceramics, and the self-healing ceramics was found to enable to attain the perfect healing at 600°C within 10 min. And we succeeded in prototype production of fiber-reinforced self-healing ceramics for low pressure turbine blade.


Author(s):  
Michael Nosonovsky

Wear occurs at most solid surfaces that come in contact with other solid surfaces. While biological surfaces and tissues usually have the ability for self-healing, engineered self-healing materials only started to emerge recently. An example of a smart self-healing material is the materials with embedded microcapsules, which rupture during crack propagation and release a healing agent that repairs the crack. We discuss the conditions under which the self-healing occurs and provide a general theoretical framework and criteria for self-healing using the concept of multiscale organization of entropy and non-equilibrium thermodynamics.


2014 ◽  
Vol 18 (2) ◽  
pp. 112-132 ◽  
Author(s):  
Hannele Kauppinen-Räisänen ◽  
Johanna Gummerus ◽  
Catharina von Koskull ◽  
Åke Finne ◽  
Anu Helkkula ◽  
...  

Purpose – Consumers gift themselves with luxury fashion brands, yet the motives for self-gifting are not well understood. Whereas traditionally, self-gifting is defined as self-orientated in nature, luxury brands are seen as social statements, and self-gifting of luxury fashion brands that combine these two controversial areas is an interesting research topic. The purpose of this paper is to address this issue by exploring the self-gifting behaviour of consumers, in particular focusing on the personal motives of gifting oneself with luxury fashion brands. Design/methodology/approach – The study takes a multi-qualitative approach involving a small (n=19) but rich sample. Data collection and analysis were triangulated to reduce researcher biases. Findings – The study provides key dimensions for understanding consumers’ perceptions of luxury fashion brands and self-gifting motives (self and socially orientated). The findings reveal that reflections from others are part of the self-gifting phenomenon. It appeared that although self-orientated benefits and personally orientated motives trigger the self-gifting act, the act of actually purchasing explicitly luxury brands for oneself as a gift may be triggered by other-orientated benefits and socially orientated motives. The findings also imply that luxury holds a self-orientated aspect; luxury brands are not only purchased for socially orientated reasons but also for reasons related to oneself. In addition, the findings discuss the act of shopping, where the act can be perceived as a luxury experience and overrun the importance of the brand. Practical implications – The findings provide insights to consumers’ gifting behaviour that may be valuable for retailers and fashion marketers as they plan for marketing activities related to their customers’ self-gifting. Originality/value – Self-gifting represents a view of gifting that remains under-researched. This study uncovers the motives for gifting oneself with luxury fashion brands, a further sub-area in need for more investigation.


2014 ◽  
Vol 636 ◽  
pp. 73-77 ◽  
Author(s):  
Xin Hua Yuan ◽  
Qiu Su ◽  
Li Yin Han ◽  
Qian Zhang ◽  
Yan Qiu Chen ◽  
...  

Microencapsulated E-51 epoxy resin healing agent and phthalic anhydride latent curing agent were incorporated into E-44 epoxy matrix to prepare self-healing epoxy composites. When cracks were initiated or propagated in the composites, the microcapsules would be damaged and the healing agent released. As a result, the crack plane was healed through curing reaction of the released epoxy latent curing agent. In the paper, PUF/E-51 microcapsules were prepared by in-situ polymerization. The mechanical properties of the epoxy composites filled with the self-healing system were evaluated. The impact strength and self-healing efficiency of the composites are measured using a Charpy Impact Tester. Both the virgin and healed impact strength depends strongly on the concentration of microcapsules added into the epoxy matrix. Fracture of the neat epoxy is brittle, exhibiting a mirror fracture surface. Addition of PUF/E-51 microcapsules decreases the impact strength and induces a change in the fracture plane morphology to hackle markings. In the case of 8.0 wt% microcapsules and 3.0 wt% latent hardener, the self-healing epoxy exhibited 81.5% recovery of its original fracture toughness.


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