Interlayer adhesion

Multilayered blends consisting of poly(4-phenylene sulfide) and nylon-6, nylon 11, nylon-12, and nylon-66, were prepared by Tateyama et al. (4). These resins had good heat, chemical, and abrasion resistance as well as excellent interlayer adhesion. 

In order to get improved interlayer adhesion, the saponification degree must be 80-95 mol-%. For gas barrier applications, the saponification degree of the EVOH of 99 mol-% is required. When the saponification is insufficient, satisfactory gas barrier properties cannot be obtained (1). 

Surlyn heat seal layer breaks away from the HDPE layer and then falls across the Surlyn layer. This type of peel seal is used, but it has its problems. If the interlayer adhesion is too much weaker than the strength of the Surlyn film layer, one ends up with a bag in a bag, which does not make the consumer happy. 

Dupont, S.R., OUver, M., Krebs, F.C., Dauskardt, R.H., 2012. Interlayer adhesion in roll-to-roU processed flexible inverted polymer solar cells. Sol Energy Mater. Sol. Cells 97,171-175. 

Ward and his coworkers investigated the interlayer adhesion in self-reinforced PP composites modified with different nano- and micron-sized particles [27-29]. They found that the introduction of a small amount of carbon nanofibers (CNFs) led to improved performance of polypropylene single-polymer composites obtained by hot compaction of oriented CNF/ PP tapes. The peel strength of a CNF/PP woven fabric composite was significantly increased. In addition, the authors pointed out that the drawn CNF/PP tapes showed substantial voiding around the fibers which were closed and sealed by the hot compaction process. As a result, the composite density increased to its initial value [27]. 

A multicoat system provides a higher probability of ensuring complete, uniform coverage of the corrodible substrate. Maintenance of interlayer adhesion is crucial. The multilayer structure might allow incorporation of many desirable properties in the outer coatings system, such as ... 

No comprehensive theory exists for predicting interlayer adhesion in coextrusion (see Adhesion). Most knowledge comes from trial-and-error testing that has led to qualitative rating charts for polymer adhesion such as the one shown in Table 3. Polymer or copolymer fiinctionality plays a strong role. Polar polymers tend to adhere to each other adhesion is difficult between nonpolar polsrmers. Some polymers form covalent bonds in addition to H-bonding, acid-base, ionic, and dipole-dipole interactions (75-78). 

Polyketones can be considered for both monolayer and multilayer constructions. The combination of good barrier properties, dimensional stability in the presence of fuel, and high burst pressures affords the possibility of a simple mono-layer construction. Should multiple layers be required, an inexpensive two-layer construction based on polyethylene and polyketones has been demonstrated to exhibit good strnctnral strength, barrier performance, and interlayer adhesion, both with and withont a tie layer. 

Hine P J, Ward I M, Jordan N D, OUey R and Bassett D C (2003) The hot-compaction behaviour of woven oriented polypropylene fibres and tapes. 1. Mechanical properties, Po/j/mer 44 1117-1131. Foster R J, Hine P J and Ward 1 M (2010) The incorporation of carbon nanofibres to enhance the interlayer adhesion of hot-compacted single-polymer polypropylene composites. Polymer 51 1140-1146. 

Keywords Interlayer adhesion loss Epoxy coatings Weathering Erosion mechanism UV absorber Humidity Water Crosslinking Network degradation Oxygen diffusion and solubility Photoproducts Oxidation zone Rain Lag time UV radiation degradation... 

The analyses conducted in this paragraph will start with a thorough discussion of an important, and often debated, model assumption and look at the experimental evidence presently available to evaluate it. Then follows an analysis of how the various effects of water on ihermoset coating degradation can be implemented in the mathematical models. Finally, a model-based analysis, considering parameters expected to affect interlayer adhesion loss, is performed. 

The siliceous skeletal system of the Western Pacific hexactineUid sponge, Euplectella aspergillum, is a complex hierarchically ordered composite (Weaver et al. 2007). The basic building blocks are laminated skeletal elements (spicules) that consist of a central proteinaceous axial filament surrounded by alternating concentric domains of consolidated silica nanoparticles and organic interlayers (adhesive). This animal also shows an interesting... 

For die attachment, polyimide adhesives have reached a peak and now the market is progressively slowing down. However, for other applications, there is a trend in the direction of thermoplastic polyimide films that can be used as interlayer adhesives. Flexible circuits and MCMs seem to be the main... 

Interlayer adhesion between a polycarbonate (PC) layer and a PC-ABS blend layer, in 3-layer films made by melt coextrusion in a multi-manifold die, was analyzed using nonlinear viscoelastic (NLVE) die-flow simulations with POLYFLOW. These simulations showed significant extensional stresses in the interface vicinity where the two melt layers come into contact for the first time. A Viscosity Normalized Nonlinearity Ratio parameter was defined to correlate the simulated interfacial melt stresses and the observed adhesion behavior. Larger deviation of this parameter from a value of 1.0 (large disparities in melt extensional configuration across the interface) corresponded to poorer observed peel strength. 

Multilayer polymeric composites combine the desirable properties of two or more polymers in a layered structure, often produced by a coextrusion process. Interlayer adhesion is critical to the performance of such composites. During coextrusion, this Interface is established as the layers flow together for a finite time through the die. 

The objective of this study is to understand the role of the coextrusion process in governing the interlayer adhesive strength in multi-layer films. 3-layer flow... 

---