Thermoreversible gels in oil/EVA systems

Barral, María Soledad; Lizaso, Isabel; Muñoz, Manuel López; Santamarı́a, Anton

doi:10.1007/s003970000145

Cited by 7 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At lower temperatures, the loss modulus becomes strongly dependent on frequency. 21,22 These samples are not thermorheologically simple materials and, therefore, it was not possible to apply the time-temperature superposition principle to the experimental linear viscoelasticity data. Thus, there is a clear tendency to a crossover between both viscoelasticity functions at high frequency and low temperature (beginning of the transition to the glassy region of the mechanical spectrum).…”

Section: Resultsmentioning

confidence: 99%

“…This behavior with the temperature is similar to that shown by traditional lithium lubricating greases previously studied 20 and as, in the case of other copolymers, the ability of the polyolefin to form physical networks can explain the gel-like mechanical behavior shown by these materials over a wide range of temperature and frequencies. 21,22 These samples are not thermorheologically simple materials and, therefore, it was not possible to apply the time-temperature superposition principle to the experimental linear viscoelasticity data. 17 This fact may be due to the development of multiphase domains depending on the temperature and polymer concentration.…”

Section: Rheological Characterization: Linear Viscoelastic Behaviormentioning

confidence: 99%

See 1 more Smart Citation

Design of lubricating grease formulations using recycled polypropylene from postconsumer films as thickener agent

Martín‐Alfonso

Valencia

Arteaga

et al. 2012

J of Applied Polymer Sci

View full text Add to dashboard Cite

This work deals with the design of lubricating greases formulations based on blends of mineral oil and recycled polypropylene from postconsumer waste, coming from films with inks. In particular, the influence of polymer concentration on the rheological, mechanical, and thermal properties of recycled polymer/oil blends was characterized. From the experimental results obtained, it can be deduced that the evolution of recycled polymer/mineral oil formulations on linear viscoelasticity functions with frequency is quite similar to that found for traditional lithium greases. It is observed that these blends form systems with enhanced ''plateau'' modulus, G o N , with respect to industrial standard lubricating greases, which could be represent an important advantage, from an economic and environmental point of view. However, the influence of temperature on linear viscoelasticity functions is more pronounced than that found for traditional greases.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Rheological Characterization: Linear Viscoelastic Behaviormentioning

confidence: 99%

Design of lubricating grease formulations using recycled polypropylene from postconsumer films as thickener agent

Martín‐Alfonso

Valencia

Arteaga

et al. 2012

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…[24] However, in the case of EVA/oil solutions, the aforementioned moduli-frequency scaling laws for the terminal zone are indeed observed. [18] The reproducibility of the results obtained in Figure 1, on cooling the solutions from above T gs , reflects the thermoreversibility of the gels.…”

Section: Resultsmentioning

confidence: 99%

“…[18,19] We have also investigated the rheology of polymer/bitumen blends. [20] In the present paper, we report on the dynamic viscoelastic results of ternary gels based on blends of EVA and SBS dissolved in a recycled engine oil.…”

Section: Introductionmentioning

confidence: 99%

Ternary Gels of a Polymer Blend and a Recycled Oil: Their Use as Bitumen Modifiers

Barral

Santamarı́a

Peña

et al. 2003

Macro Materials & Eng

View full text Add to dashboard Cite

A blend of random ethylene‐vinyl acetate copolymer (EVA) and triblock styrene‐butadiene‐styrene copolymer (SBS) was dissolved in a recycled engine oil to obtain ternary thermoreversible gels. As the temperature was increased, first a network associated with EVA disappeared, and a second one associated with SBS dominated, maintaining the elastic response of the system. The principal advantage of these ternary systems is that their mechanical properties and thermal stability are better than that of binary gels. These gels, made from waste, can be used as bitumen modifiers to obtain binders of improved properties and good stability, which are useful for road surfacing.Temperature sweeps of elastic modulus performed at a frequency of 1 Hz.magnified imageTemperature sweeps of elastic modulus performed at a frequency of 1 Hz.

show abstract

“…In this case, it may be attributed to the colloidal gel network formed by EVA and iPP polymers, respectively. These systems obey the definition of gel where G ′ > G ″ with both moduli showing some significant frequency dependence at low frequencies and elastic equilibrium modulus, G e , can be defined:

G_{e} = \lim_{ω \to 0} G^{'}

…”

Section: Resultsmentioning

confidence: 99%

Linear and nonlinear viscoelasticity of oleogels based on vegetable oil and ethylene vinyl acetate copolymer/isotactic polypropylene blends

Alfonso

Valencia

2015

J of Applied Polymer Sci

View full text Add to dashboard Cite

This work deals with a rheological study of oleogels based on high-oleic sunflower oil (HOSO) and ethylene vinyl acetate copolymer (EVA) / isotactic polypropylene (iPP) blends. EVA copolymers with different vinyl acetate content were used. With this aim, linear small amplitude oscillatory shear (SAOS) and nonlinear (relaxation) measurements combined with polarized optical microscopy were carried out. Oleogels were prepared by using the mixing rheometry technique in a batch mixer. Oscillatory strain amplitude sweep tests showed that the end from the viscoelastic linear region for oleogels was accompanied by opposite trends for viscoelastic moduli. SAOS tests showed that all the oleogels present similar behavior characteristic of polymeric systems with physical entanglements. It was found that the elastic equilibrium modulus and loss tangent increases with iPP content. On the other hand, nonlinear relaxation tests presented a strong dependence on the strain applied and the Soskey-Winter model was found to provide an accurate description of the damping function of these oleogels.

show abstract

Thermoreversible gels in oil/EVA systems

Cited by 7 publications

References 0 publications

Design of lubricating grease formulations using recycled polypropylene from postconsumer films as thickener agent

Design of lubricating grease formulations using recycled polypropylene from postconsumer films as thickener agent

Ternary Gels of a Polymer Blend and a Recycled Oil: Their Use as Bitumen Modifiers

Linear and nonlinear viscoelasticity of oleogels based on vegetable oil and ethylene vinyl acetate copolymer/isotactic polypropylene blends

Contact Info

Product

Resources

About