Heterogeneity of a vulcanized rubber by the formation of ZnS clusters

Dohi, Hidehiko; Horiuchi, Shin

doi:10.1016/j.polymer.2007.03.004

Cited by 42 publications

(25 citation statements)

References 22 publications

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“…In sulfurcured polyisoprene rubber (IR) such inhomogeneities may partially be due to ZnO clusters, as found by TEM. 80 The present NMR study provides more local information, as spatial cross-linking inhomogeneities are detected on scales of several nanometers and above, where the lower limit is set by the length scale of dynamic averaging of monomers in different chains. In conclusion, based on the given literature one may conclude that NR (or IR) samples vulcanized with sulfur exhibit a rather homogeneous rubber matrix down to very local scales, with inhomogeneities at larger scales arising from the nonrubber components.…”

Section: Resultsmentioning

confidence: 89%

Inhomogeneities and Chain Dynamics in Diene Rubbers Vulcanized with Different Cure Systems

et al. 2010

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In this study, we focus on qualitative differences in the network structure and dynamics of natural as well as poly(butadiene) rubber in dependence of the cure system (sulfur/accelerator or organic peroxide) used in the vulcanization process. The spatial homogeneity of the distribution of chemical and physical cross-links in the network is assessed via the quantitative measurement of proton-proton residual dipolar couplings as measured by static multiple-quantum (MQ) NMR spectroscopy at low field. The experiment also provides information on the apparent correlation time of fast segmental fluctuations that dominate chain relaxation processes at lower temperature, for which we also find characteristic differences. Vulcanization via a radical mechanism (using organic peroxides) leads to networks with a high content of nonelastic defects (loops or dangling chains), a rather inhomogeneous distribution of cross-links, and modified (slower) local dynamics, as compared to networks obtained by sulfur vulcanization. These microstructural factors can be related with the well-known differences in the macroscopic properties of diene rubbers vulcanized with different cure systems.

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Section: Resultsmentioning

confidence: 89%

Inhomogeneities and Chain Dynamics in Diene Rubbers Vulcanized with Different Cure Systems

et al. 2010

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“…Recently, HAADF has also been used to image organic materials. 9,10 In this study, HAADF images for the nano-alloyed material were collected by scanning TEM (STEM), where the image was produced from the narrow electron beam. Figure 6 shows the collected image for the biaxially stretched nanoalloyed film of PET/polyimide (90/10 weight %).…”

Section: Demonstration Of the Nano-sized Polyimide Domainsmentioning

confidence: 99%

Development and industrialization of a biaxially stretched nano-alloyed film

Tsunekawa

Higashioji

Hosokawa

et al. 2012

Polym J

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The novel concept and significance of a nano-alloyed polymer, which includes nano-dispersed domains, is proposed, and a biaxially stretched nano-alloyed film is developed. The developed film has a higher glass transition temperature and improved dimensional stability compared with regular poly(ethylene terephthalate) (PET) films. Nano-sized polyimide domains are dispersed with our original melting extrusion process, which produces highly concentrated polyimide master batches at much lower temperatures than the regular processing temperature of the polyimide. The biaxially stretched film has been industrialized for use as a substrate for data storage tapes and can additionally be applied to materials in the fields of electronic devices, automobile, environmental and energy devices. Polymer Journal (2012) 44, 1170-1178; doi:10.1038/pj.2012.96; published online 13 June 2012Keywords: biaxially stretched film; glass transition temperature; nano alloy; nanostructure control technology; polyester; polyimide INTRODUCTION Development of a biaxially stretched nano-alloyed film Biaxially stretched polyester films, which are represented by poly (ethylene terephthalate) (PET) films, are currently the most widely used polymeric substrate materials in the fields of display technologies, electronic devices, storage media, electronic insulators, automobile, molding, package, printing and architecture. This widespread use is a result of the films possessing high strength, durability, transparency, flexibility and good surface properties. Information and telecommunications equipment have recently required more compactness and portability as well as excellent film properties, such as higher heat resistance and dimensional stability, especially in the field of electronics, environment and energy. It has been difficult for conventional biaxially stretched PET films to meet the future demand, and outstanding films with cost effectiveness are required.We have created a biaxially stretched nano-alloyed PET film that has a higher glass transition temperature, which is an intrinsic property of polymers, compared with regular biaxially stretched PET films. 1 The technical points from our development are the following. First, the novel concept and significance of nano-alloyed polymers have been proposed. Secondly, nanostructure control technology has been developed for the nano-sized dispersion of polyimide, which is a different organic polymeric material than polyester. Finally, the processing conditions for the biaxially stretched nano-alloyed films have been established. In this paper, we describe the design of a nano-alloyed polymer and biaxially stretched films.

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“…A species often identified in rubber blooming is zinc sulfide which is formed from zinc oxide during sulfur vulcanization. 15,16 Migration of sulfur itself can also occur and blooming, in general, appears to be more prominent in sulfur cured formulations than in peroxide cured formulations. 1,17 Ingredients such as waxes and similar low molecular weight species readily migrate to the surface and this blooming has been related to concentration, temperature and also pressure.…”

Section: Sublayers Surface Features and Rubber Bloomingmentioning

confidence: 99%

Material morphology and electrical resistivity differences in EPDM rubbers

Domeier

Yang

2008

J of Applied Polymer Sci

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Electrical resistance anomalies noted in EPDM gaskets have been attributed to zinc-enriched surface sublayers, about 10-lm thick, in the sulfur cured rubber material. Gasket over-compression provided the necessary connector pin contact and was also found to cause surprising morphological changes on the gasket surfaces. These included distributions of zinc oxide whiskers in high pressure gasket areas and cone-shaped features rich in zinc, oxygen, and sulfur primarily in low pressure protruding gasket areas. Such whiskers and cones were only found on the pin side of the gaskets in contact with a molded plastic surface and not on the back side in contact with an aluminum surface. The mechanisms by which such features are formed have not yet been defined.

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Heterogeneity of a vulcanized rubber by the formation of ZnS clusters

Cited by 42 publications

References 22 publications

Inhomogeneities and Chain Dynamics in Diene Rubbers Vulcanized with Different Cure Systems

Inhomogeneities and Chain Dynamics in Diene Rubbers Vulcanized with Different Cure Systems

Development and industrialization of a biaxially stretched nano-alloyed film

Material morphology and electrical resistivity differences in EPDM rubbers

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