Home About us Contact
|
Home About us Contact | ||
|
|
||
Paint Film (paint + film)
Selected AbstractsRheological and curing behavior of aqueous ambient self-crosslinkable polyacrylate emulsionJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007Xiaohua Liu Abstract An aqueous ambient crosslinkable polymer acrylic (AACPA) emulsion was obtained by adding adipic acid dihydrazide (ADH) to the polyacrylate emulsion incorporating diacetone acrylamide (DAAM), and this emulsion was synthesized by two feeding materials methods. The AACPA emulsion and its paint film were characterized with rheological measurements, laser light scattering, Fourier transform infrared, torsional braid analysis (TBA), DTA, and so on. The results showed that AACPA emulsion was pseudoplastic fluid and pseudoplasticity increased with increasing of DAAM content. The results also showed that water resistance, solvent resistance, and thermotacky temperature of AACPA paint film increased with increasing of the content of DAAM. The results dealing with curing behavior of the paint film showed that adding organic swelling solvent and organic acid to the AACPA emulsion can accelerate the curing speed of the paint film. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source] Impact of cooling method and incoming sheet quality on final part surface quality in thick sheet paint film thermoformed parts,,POLYMER ENGINEERING & SCIENCE, Issue 1 2009Kedzie D. Fernholz Thick sheet, "dry paint" film parts were thermoformed using different cooling methods and sheet temperatures to determine whether these two parameters had a direct effect on the surface quality of the final part. Although some thermoformers have claimed that applying chilled air after forming "dry paint" film parts improves the gloss of the parts, the data from this study showed that application of chilled air did not have an effect on either the parts' initial gloss or their gloss after time-dependent hazing. The critical factor in maintaining surface quality in these parts was the maximum temperature reached by the "dry paint" film during heating. In addition, analysis of the data taken on the sheet prior to forming versus that taken on the part after forming demonstrated the importance of validating the surface quality of the as-received sheet prior to conducting process versus appearance experiments. On the basis of these findings, a recommendation is made for incoming sheet surface quality levels for both process development studies and production applications. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers [source] Photocatalytic Coatings for Environmental Applications,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Norman S. Allen ABSTRACT A series of nano- and micronparticle-grade anatase and rutile titanium dioxide pigments have been prepared with various densities of surface treatments, particle size and surface area. Their photocatalytic activities have been determined in a series of paint films by FTIR, chalking, color, gloss change and weight loss after artificial weathering. The pigments have also been examined by rapid assessment methodologies using photodielectric microwave spectroscopy, 2-propanol oxidation and hydroxyl analysis. The microwave response under light and dark cycles provides an extended timescale probe of chargecarrier dynamics in the pigments. Pigment particle size, surface area and properties clearly play an important role in dispersion and any polymer-pigment interactions. Photooxidation studies on several types of paint films show a clear demarcation between nanoparticle- and pigmentary-grade titanium dioxide, with the former being more active because of their greater degree of catalytic surface activity. The photosensitivity of titanium dioxide is considered to arise from localized sites on the crystal surface (i.e. acidic OH), and occupation of these sites by surface treatments inhibits photoreduction of the pigment by ultraviolet radiation; hence, the destructive oxidation of the binder is inhibited. Coatings containing 2,5% by weight alumina or alumina and silica are satisfactory for generalpurpose paints. If greater resistance to weathering is desired, the pigments are coated more heavily to about 7,10% weight. The coating can consist of a combination of several materials, e.g. alumina, silica, zirconia, aluminum phosphates of other metals. For example, the presence of hydrous alumina particles lowers van der Waals forces between pigments particles by several orders of magnitude, decreasing particle-particle attractions. Hydrous aluminum oxide phases appear to improve dispersibility more effectively than most of the other hydroxides and oxides. Coated nanoparticles are shown to exhibit effective light stabilization in various water- and oilbased paint media in comparison with conventional organic stabilizers. Hindered piperidine stabilizers are shown to provide no additional benefits in this regard, often exhibiting strong antagonism. The use of photocatalytic titania nanoparticles in the development of self-cleaning paints and microbiological surfaces is also demonstrated in this study. In the former case, surface erosion is shown to be controlled by varying the ratio of admixture of durable pigmentary-grade rutile (heavily coated) and a catalytic-grade anatase nanoparticle. For environmental applications in the development of coatings for destroying atmospheric pollutants such as nitrogen oxide gases (NOX), stable substrates are developed with photocatalytic nanoparticle-grade anatase. In this study, porosity of the coatings through calcium carbonate doping is shown to be crucial in the control of the effective destruction of atmospheric NOx gases. For the development of microbiological substrates for the destruction of harmful bacteria, effective nanoparticle anatase titania is shown to be important, with hydrated high surface area particles giving the greatest activity. [source] | ||||||||||