Tham khảo tài liệu 'coatings of polymers and plastics part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 114 Berta and the adhesion is still good this is a surprise that one would probably not predict or may not even find because you probably wouldn t look for it . This demonstrates some of the power of selective elimination. Analysis of the durability results shows that the key ingredient for this property is the PE-1 without it durability suffers significantly. Formulation T 14-3 without the MAgPP does have a little adhesion. Apparently the adhesion is not good enough to allow for the positive interaction effect of the PE-1 on durability to come into play. This same kind of analysis can be done on all the properties. There may be some way to describe this method of selective elimination in a mathematical relationship of the properties to the ingredients but it is beyond the scope of this chapter. Interested statisticians are invited to use or abuse this method but personally I like it. Modified Paint and Polymer System There has been an alternate approach to painting TPOs that essentially involves making the paint less polar to match more nearly the surface energetics of the TPO. The additives are basically hydroxy-terminated hydrogenated polybutadiene that is also termed hydroxy terminated ethylene butene copolymer OHPEB . This involves a very drastic change in the paint formulation with significant amounts of the additive 31 . The paint properties are effected by this change and it is very difficult to match the properties of the standard more polar paints. Formulating the paints for painting onto TPO adds cost to the paint system the overall cost savings by eliminating the adhesion promoter and using the modified paint has not been completely defined. The cost of this specially developed TPO paint would be very formulation dependent and volume-usage dependant. Those who have developed this technology appear to show an overall cost advantage although it is not clear if PTE has been considered. What is believed by this author and others 32 is that by employing
