The number of conjugate states for the flow of a fluid system of two layers is investigated by means of the momentum principle. The uniqueness of the conjugate state is proved for the cases in which the modified Froude number for either layer is predominantly large. Specific experimental results for three special cases demonstrate the uniqueness of the state downstream from the hydraulic jump, and show that, for a first approximation, the simple analysis provides a means for determining the downstream depths, with smaller errors for lower jumps.

Acrylonitrile-styrene-acrylic (ASA) terpolymer was blended with a sodium neutralized poly (ethylene-co-methacrylic acid) ionomer to develop a weather-resistant ASA with good heat sealing and adhesion properties. Both tensile strengths and modulus were reduced by about 45% with an increase in Na-ionomer concentration of 50%. The mechanical data were fitted with different models that predict mechanical behavior. The thermal stability was increased with the incorporation of ionomer. The temperature corresponding to 50% mass loss (T m50 ) was increased from 400 C (for ASA) to 427 C for 50/50 ASA/Na-ionomer blend. SEM and AFM micrographs reveal the cone-shaped microstructure on the ASA matrix surface after a critical Na-ionomer concentration of 30%. This blend system follows typical non-Newtonian behavior. The heat sealing performance study with metal was also carried out to investigate the utilization of these blend systems as a protective layer for metal. POLYM. ENG. SCI., 55:1571-1579, 2015

A special class of engineered copolymers, called ionomers, comprising both electrically neutral repeating units and a fraction of ionized units was melt blended to weather resistant acrylonitrile/styrene/acrylate (ASA) terpolymer for improved electrical conductivity, heat sealing ability, direct adhesion to several polymers, glass and metals without affecting the aesthetics and colorability of ASA. The similar chemical nature of one of the components of each blended materials viz. acrylate rubber in ASA and acrylic acid of Na-ionomer in addition to the presence of ionic crosslinking within Na-ionomer, polar acrylonitrile group in ASA affects chain dynamics as compared to neat polymers. In this context, dynamic rheological properties, DMA properties, creep behavior and DSC of the newly developed ASA/Na-ionomer blends were analyzed. Based on Na-ionomer content, the blend system either forms "mushroom" or "brush" type conformation and formation of ionic crosslinking in "brush regime" leads to three tiers Caylay tree conformation. The different chain topology resulted into characteristic loss modulous (G″) curve during stress relaxation process. The chain conformation as well as ionic crosslinking and ion-dipole interaction between the blend components also affected DSC endotherm peak and glass transition temperature. The tan δ peak temperature from DMA also revealed the similar observation. The creep compliance of the blends was dependent on Na-ionomer content and with temperature. The Findley model analysis of creep compliance suggested that the creep compliance was depended on Na-ionomer content and ionic crosslinking controlled the creep. The findings can be utilized to design weather resistant smart polymer using suitable filler system.

The present manuscript is aimed at the development of the protective layer for metal components for outdoor applications such as telecommunication components. Multiwalled carbon nanotubes at varying weight (from 0.5% to 5.0% by weight) were incorporated into newly developed 50/50 blend of acrylonitrile styrene acrylate (ASA) and ethylene acrylic acid-based Na-ionomer blend. ASA has inherent weather-resistant property whereas Na-ionomer has high affinity to adhere metal components. Nanocomposites were prepared by melt blending technique and were evaluated for thermal properties (thermogravimetric analysis and differential scanning calorimetry), dynamic mechanical analysis, and creep as well as recovery properties. Up to 1% nanotube content, there were predominant polymer/nanotube interactions; further addition resulted in nanotube networks formation that reduced polymer/nanotube interactions. These interactions increased both the thermal stability and storage modulus till 1% nanotube concentration, and after that, decreasing trend is observed. The creep deformation, as well as recovery, shows the opposite trend. In addition, the nanotube/nanotube sliding above 1% nanotube content increased the creep deformation further. The higher temperature played an altogether different role during recovery of the nanocomposite. The different polymer chain parts of the "brush" type ASA/Na-ionomer blend interacted differently with carbon nanotubes; the ionic aggregates peak position of Na-ionomer in differential scanning calorimetry thermogram was influenced by multiwalled carbon nanotubes, but the endotherm peak due to polyethylene crystallites of Na-ionomer was unaffected. Carbon nanotubes also affected the glass transition temperature of polystyrene acrylonitrile matrix of ASA.

The number of conjugate states for the flow of a fluid system of two layers is investigated by means of the momentum principle. The uniqueness of the conjugate state is proved for the cases in which the modified Froude number for either layer is predominantly large. Specific experimental results for three special cases demonstrate the uniqueness of the state downstream from the hydraulic jump, and show that, for a first approximation, the simple analysis provides a means for determining the downstream depths, with smaller errors for lower jumps.