Bond strength between polymers

The wet fastness is determined by the bond strength between polymer and dyestuff, and therefore by the presence of specific functional groups in the polymer. 

The heat (sublimation) fastness increases with the bond strength between polymer and dyestuff and with the sublimation temperature of the dyestuff. 

Coupling agents Improve compatibility, bond strength between polymer and reinforcement or filler Epolene-Eastman Hostaprime - Clariant Ken-React. Ken-Stat - Kenrich... 

Lubricants which are less soluble or incompatible with the base polymer provide external lubrication in the molten phase. In this case the bond strength between polymer and lubricant is weak and under high shear the lubricant is, in effect, squeezed out of the compound. Thus, the lubricant provides external lubrication by covering the surfaces of the processing equipment, reducing friction at the interface of the polymer and the metal surfaces of the machinery. 

Crete is stressed in tension. Although the tensile strength of concrete-polymer is higher by a factor of 4 than that of concrete, it is still relatively low compared with that of steel. Standard tests on reinforcing bars in which a 1-inch diameter steel rod is pulled out of a 6-inch diameter concrete cylinder indicated that the force needed to pull the bar from a concrete-polymer cylinder was three times the force required for a cylinder of ordinary concrete. This greatly improved bond strength between concrete-polymer and steel is important in concrete structural design. 

Stability in terms of 1) resistance to degradation or dissolution in aqueous and nonaqueous media, 2) bond strength between the redox sites and polymer matrix, and 3) adherence between the polymer film and the electrode surface. 

Pull-out tests were also conducted to measure the bond strength between the polymer concrete overlay and the Portland cement concrete substrate before and after the thermal compatibility test. The results are shown in Table 9. 

For mechanical testing of the bond strength between an embedded electrode and the (modified) EAP material, which was polymerized with the electrode(s) in place, a heavy counterweight was used while the electrode was pulled at a consistent rate until the electrode broke free and detached from the polymer. For stainless steel and for titanium, oxygen plasma treatment produced the strongest... 

Fu, X., Lu, W., and Chung, D.D.L. (1996) Improving the bond strength between carbon fiber and cement by fiber smface treatment and polymer addition to cement mix. Cement and Concrete Research 26,1007-1012. 

As the material passes further down the extruder barrel, the temperature increases which reduces the bond strength between the molecules. Ultimately melting takes place at a point dependent upon the frictional forces and the strength of the matrix to form a network within an homogeneous mass of molten polymer. 

Mechanical properties such as tensile strength and modulus of the blends depend on the degree of interfrcial bond strength between the two polymeric phases and morphology. (lenerally, the formation of fibrils of one polymer within the other with high aspect ratio increases the tensile properties of the blend. In particular, reinforcement of the fibers reportedly (32) occurs above some critical a ect ratio below which no reinforcement occurs A fibrous filler transfers the applied mechanical load from the matrix to the reinforcement and in fibers with aspect ratios lower than a critical value, a conq>lete load transfer may not be achieved. 

The interfacial acid-base function theory was put forward the first time in 1962 by Fowks. This theory holds that the filler and polymer matrix of a composite material can be treated as a generalized acid or alkali. When the surfaces of the filler and polymer matrix have different acids or alkalis, they are easy to combine. The greater their difference in pH, the more easily they will combine. When the surfaces of the filler and polymer matrix have the same acid or alkali, the surface of the filler should be modified to change its pH value. The different surface pH values are beneficial to improve the bonding strength between the reinforced material and polymer matrix and improve the performance of filled plastics. 

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