Showing papers on "Surface modification published in 1972"

Method of surface modification of polymer materials

Abstract: A method of surface modification of polymer materials, according to which said materials are treated with an aqueous solution comprising a mineral acid, a mineral oxidant, and a salt of hydrochloric, hydrobromic, or hydroiodic acid. Water, said mineral acid, mineral oxidant and salt are taken in a weight ratio of 50-1000:0.3-7:0.1-7:1-15 respectively. By carrying out modification of polymer materials in accordance with the present method, the initial strength of the treated materials remains unaffected. Moreover, in the process of treating the materials, the latter acquire desired adhesion properties, whereby strength of cementing of polymer materials with each other, with metals, wood, glass-reinforced plastics and glass is ensured.

Enhancement of Surface Wettability of Abhesive Silicone Rubber by Oxidation

Abstract: A new method to detect surface oxidation of an otherwise untreated, cross-linked and filled silicone rubber is described. Our method is established on the principle that surface wettability increases during the progress of oxidation. Surface wettability is determined in terms of critical surface tension. Abhesive polymers, of which silicone rubber is a typical example, are characterized by low surface energy, low friction coefficient and low release value. The problem associated with silicone rubber is its poor adhesion to other polymers. Its adhesional ability, however, can be improved by surface modification, e.g. oxidation, treatment with corona discharge, or ionic bombardment with inert gases. By our method we found that the oxidation of silicone rubber is comparatively mild below 260°C, but is intensified at 287°C. Excessive oxidation at 316°C results in the formation of low molecular weight siloxanes which lower the wettability of the oxidized surface. Mechanisms of thermal oxidation are di...

Electrolytic process for the surface modification of high modulus carbon fibers

Abstract: An improved electrolytic process is provided for modifying the surface characteristics of an electrically conductive high modulus graphitic carbonaceous fibrous material (i.e., exhibiting a mean single filament Young''s modulus of at least about 60 million psi) and to thereby facilitate enhanced adhesion between the fibrous material and a resinous matrix material. The electrolytic process is carried out upon immersion of the fibrous material in an aqueous electrolytic solution of sodium hypochlorite (as defined) provided at a moderate temperature for a relatively brief residence time (i.e., about 2 to 10 minutes) while subjected to a relatively low current density (i.e., about 2.5 to 12 milliamps per square centimeter of surface area of fibrous material), and thereafter washing the same. Composite articles of enhanced interlaminar shear strength may be formed by incorporating the fibers modified in accordance with the present process in a resinous matrix material.

Surface-modification of polymer films, fibres, etc. - by formation of caten-ane - or rotaxane-like bonds by a grafting reaction

Abstract: To the surface of a polymer A, there is grafted a chemically different second component C which may be polymer, oligomer or monomer but is not the same as A, but which reacts with bi- or polyfunctional cpds. B already incorporated in A, ring formation occuring in the catenane or rotaxane manner, in which >=1 chains of polymer A may be included.

Surface modification of graphite fibers

Abstract: Graphite fibers exhibiting an enhanced ability to bond to a matrix material (e.g., a thermosetting resinous material or a metallic material) are produced wherein a film of amorphous carbon in intimate association with titanium is provided upon the surface of the same. A predominantly graphitic carbonaceous fibrous material is coated with a film of a dihydropyridacene polymer in intimate association with a hydrolyzable organotitanium compound, the organotitanium compound hydrolyzed to form titanium dioxide, and the polymer portion of the film carbonized to a predominantly amorphous form. Composite articles which incorporate the carbon fibers produced by the present process exhibit improved physical properties, such as an improved interlaminar shear strength.

Surface Modification of Wool and Other Fibrous Materials by 4-Vinylpyridine and Zinc Chloride1

Abstract: Wool, cotton, polyester, and leather were durably modified by 4-vinylpyridine and zinc chloride applied in acetone. The pendant pyridine rings of the surface deposit, probably poly (4-vinylpyridine), may be free or coordinated through nitrogen with zinc, which may also be bonded to the substrate. Treated wool fabrics resist shrinkage when laundered.