8 research outputs found
聽Effect of epoxy and polyurethane coating modification with nanofillers on their resistance to erosive wear
The paper presents investigation results of the effect of epoxy and polyurethane coating modification with three kinds of nanofillers on the resistance to erosive wear. Particles of granulated alundum of grain size 0,6-0,7 mm were used as the abrasive material. They fall freely from the height of 0,94 m and impact the coating surface at an angle of 45掳. All polyurethane coatings modified with nanofillers showed higher resistance to erosive wear than the unmodified coatings, regardless of the applied nanofiller. However, the nanofiller modified epoxy coatings showed lower resistance to erosive wear than the unmodified ones
The Influence of Battery Acid on the Destruction of Acrylic Coatings of Car Bodies
Renovation coatings of car bodies undergo destruction under the influence of operational factors. Like ultraviolet radiation, erosion, and aggressive media (among others, battery acid). This article concerns the evaluation of the influence of battery acid on the destruction of acrylic coatings previously non-aged, as well as aged climatically for 2 years. Ageing of the coatings with battery acid contributed to a degradation increase of their chemical structure. It was supported by a considerable increase in the polar component of surface free energy (SFE) of the coatings. In the case of prior climate ageing, the increase in the polar component was even higher. Moreover, the coating鈥檚 ability to absorb battery acid increased, which induced blistering. The DSC method revealed that the action of battery acid caused more intense oxidation of coating material, and as a result, the brittleness increased, leading to chipping of the coating surface layers. This led to the increase in surface roughness, measured using an interferometric method. The coatings previously climatically aged for 2 years presented higher values of surface roughness parameters than the non-aged ones. The increase in the surface roughness contributed to a substantial decrease in the gloss of coatings. A sharp difference in colour escalating with the lengthening of the ageing period was also observed using the spectrophotometric method
Analiza wp艂ywu destrukcji nawierzchniowej pow艂oki poliuretanowej na kinetyk臋 erozji systemu pow艂ok poliuretanowo-epoksydowych
The paper presents results of investigations concerning influence of climatic factors and environmental pollution on chemical and physical destruction of polyurethane top coat. In order to increase the operational life of polyurethane coating, its composition was modified by nanoparticles addition of aluminium dioxide (of grain size d=20 nm) or silica (of grain size d=16 nm), which mass share was 3%. Three-year ageing on climatic station of coating systems samples with such modified top coat as well as with unmodified top coat caused its chemical destruction as FTIR (Fourier-transform infrared spectroscopy) examinations documented relevant increase of carbonyl groups (C=0) content. This fact testified oxidation degree rise of superficial layers which indicated their oxidation resistance decrease. Also oxidation initial temperature decrease of polyurethane coating was revealed using DSC (Differential Scanning Calorymetry). Influence of climatic factors and environmental pollution contributed also to the physical destruction of the coating which caused an increase of its surface roughness and generated craters, etchings and cracks (including the silver cracks). Destruction degree of climatically aged polyurethane coating influenced erosive wear intensity of three-layer polyurethane-epoxy coating system. The lowest chemical and physical destruction under the influence of operational factors as well as the highest hardness revealed the coating systems with polyurethane top coat modified with aluminium dioxide what was the reason that they showed also the lowest erosive wear intensity. On the other hand, aged analogously coating systems with polyurethane top coat modified with silica were marked by comparably bigger destruction than the coating systems modified with aluminium dioxide which was the reason of their erosive wear intensity increase.W artykule przedstawiono wyniki bada艅 wp艂ywu naturalnych czynnik贸w klimatycznych oraz zanieczyszcze艅 艣rodowiskowych na destrukcj臋 chemiczn膮 i fizyczn膮 nawierzchniowej pow艂oki poliuretanowej. Celem zwi臋kszenia trwa艂o艣ci eksploatacyjnej pow艂oki poliuretanowej wprowadzono do jej sk艂adu nanocz膮stki tlenku glinu (o rozmiarze ziarna d=20 nm) lub krzemionki (o rozmiarze ziarna d=16 nm), kt贸rych udzia艂 masowy wynosi艂 3,5%. Starzenie pr贸bek system贸w pow艂okowych, zar贸wno z tak zmodyfikowan膮 pow艂ok膮 nawierzchniow膮, jak i z pow艂ok膮 nawierzchniow膮 niemodyfikowan膮, na stacji klimatycznej w okresie 3 lat spowodowa艂o destrukcj臋 chemiczn膮 pow艂oki nawierzchniowej. Badania spektroskopowe w podczerwieni (FTIR) udokumentowa艂y bowiem istotne zwi臋kszenie zawarto艣ci grup karbonylowych (C=O), 艣wiadcz膮ce o wzro艣cie stopnia utlenienia warstw nawierzchniowych, co wskazuje na zmniejszenie ich odporno艣ci oksydacyjnej. Na podstawie analizy termicznej DSC (r贸偶nicowej kalorymetrii skaningowej) ustalono r贸wnie偶 obni偶enie temperatury pocz膮tku utleniania pow艂oki poliuretanowej. Oddzia艂ywanie czynnik贸w klimatycznych i zanieczyszcze艅 艣rodowiska przyczyni艂o si臋 tak偶e do destrukcji fizycznej tej pow艂oki. Skutkowa艂o to wzrostem chropowato艣ci jej powierzchni oraz tworzeniem: krater贸w, wytrawie艅, i p臋kni臋膰 (w tym p臋kni臋膰 srebrzystych). Stopie艅 destrukcji starzonej klimatycznie pow艂oki poliuretanowej mia艂 wp艂yw na intensywno艣膰 zu偶ywania erozyjnego tr贸jwarstwowego systemu pow艂ok poliuretanowo-epoksydowych. Najmniejsz膮 destrukcj膮 chemiczn膮 oraz fizyczn膮 pod wp艂ywem czynnik贸w eksploatacyjnych oraz najwy偶sz膮 twardo艣ci膮 wyr贸偶nia艂y si臋 systemy pow艂okowe z poliuretanow膮 warstw膮 nawierzchniow膮 modyfikowan膮 tlenkiem glinu, co by艂o przyczyn膮 najni偶szej intensywno艣ci ich zu偶ywania erozyjnego. Natomiast starzone klimatycznie systemy pow艂okowe z poliuretanow膮 warstw膮 nawierzchniow膮 modyfikowan膮 krzemionk膮 charakteryzowa艂y si臋 por贸wnywalnie wi臋ksz膮 destrukcj膮, ni偶 systemy pow艂okowe modyfikowane tlenkiem glinu, co zwi臋kszy艂o intensywno艣膰 ich zu偶ywania erozyjnego
Evaluation of UV radiation influence on abrasivity of protective-decorative coatings for car bodies
W artykule przedstawiono badania zar贸wno w艂asno艣ci fizykochemicznych, jak i odporno艣ci na 艣cieranie (艣cieralno艣ci) tr贸jwarstwowych system贸w pow艂ok akrylowo-poliestrowych (renowacyjnych), poddanych starzeniu promieniowaniem ultrafioletowym (UV). Fotodestrukcja i fotodegradacja warstw powierzchniowych badanych pow艂ok, wywo艂ana promieniowaniem UV, skutkowa艂a wykruszaniem ich fragment贸w. Mia艂o to wp艂yw na systematyczne obni偶anie grubo艣ci oraz twardo艣ci pow艂ok, w miar臋 up艂ywu okresu ich starzenia. Starzenie UV spowodowa艂o r贸wnie偶 prawie dwukrotny wzrost warto艣ci parametr贸w Ra oraz Rz chropowato艣ci ich powierzchni. Rosn膮ca (wraz z wyd艂u偶aniem okresu starzenia) chropowato艣膰 powierzchni starzonych pow艂ok, jak i malej膮ca twardo艣膰 przyczyni艂y si臋 do zmniejszania si臋 ich odporno艣ci na 艣cieranie, mierzonej ubytkiem masy 艣cieranego (z zastosowaniem aparatu T-07) materia艂u pow艂okowego.The paper presents investigations concerning physico-chemical properties as well as a resistance to abrasion (abrasivity) of three-layer acrylic-polyester (renovation) coating systems after ageing with ultraviolet (UV) radiation. Generated by UV radiation photo-destruction and photodegradation of examined coatings surface layers caused their chipping. This had an impact on progressive decline of the coatings thickness and hardness with the ageing time flow. UV ageing caused also almost twofold increase in surface roughness parameters Ra and Rz values. Surface roughness of the aged coatings increasing with the ageing time flow as well as their decreasing hardness contributed to their resistance to abrasion decrease, measured with the mass loss of abraded (using T-07 apparatus) coating material
Influence of aqueous sodium chloride solutions on operational properties of epoxy coatings
The main goal of the research presented in the article is to assess the impact of the destruction (degradation) of epoxy coatings, caused by the influence of a 25% aqueous solution of sodium chloride (brine), on the operational properties that determine the coatings reliability (durability). Samples of two-layer epoxy coatings (obtained from powder paints) were aged by immersing them in brine for a maximum period of 1680 h. The following criteria were used to assess the operational properties of the coatings: thickness, roughness and surface morphology, hardness, water absorption (mass increase), surface free energy. The FTIR and DSC tests performed showed a progressive development of the oxidation processes of the epoxy with the ageing period. The long-term impact of the brine resulted in the destruction of the coatings in the form of: craters, grooves, microcracks, including silver cracks. The contact of the coatings with brine also increased their: surface roughness (Ra, Rz, Rmax), thickness, mass, surface free energy, and decreased hardness and heat resistance
Evaluation of UV radiation influence on abrasivity of protective-decorative coatings for car bodies
W artykule przedstawiono badania zar贸wno w艂asno艣ci fizykochemicznych, jak i odporno艣ci na 艣cieranie (艣cieralno艣ci) tr贸jwarstwowych system贸w pow艂ok akrylowo-poliestrowych (renowacyjnych), poddanych starzeniu promieniowaniem ultrafioletowym (UV). Fotodestrukcja i fotodegradacja warstw powierzchniowych badanych pow艂ok, wywo艂ana promieniowaniem UV, skutkowa艂a wykruszaniem ich fragment贸w. Mia艂o to wp艂yw na systematyczne obni偶anie grubo艣ci oraz twardo艣ci pow艂ok, w miar臋 up艂ywu okresu ich starzenia. Starzenie UV spowodowa艂o r贸wnie偶 prawie dwukrotny wzrost warto艣ci parametr贸w Ra oraz Rz chropowato艣ci ich powierzchni. Rosn膮ca (wraz z wyd艂u偶aniem okresu starzenia) chropowato艣膰 powierzchni starzonych pow艂ok, jak i malej膮ca twardo艣膰 przyczyni艂y si臋 do zmniejszania si臋 ich odporno艣ci na 艣cieranie, mierzonej ubytkiem masy 艣cieranego (z zastosowaniem aparatu T-07) materia艂u pow艂okowego.The paper presents investigations concerning physico-chemical properties as well as a resistance to abrasion (abrasivity) of three-layer acrylic-polyester (renovation) coating systems after ageing with ultraviolet (UV) radiation. Generated by UV radiation photo-destruction and photodegradation of examined coatings surface layers caused their chipping. This had an impact on progressive decline of the coatings thickness and hardness with the ageing time flow. UV ageing caused also almost twofold increase in surface roughness parameters Ra and Rz values. Surface roughness of the aged coatings increasing with the ageing time flow as well as their decreasing hardness contributed to their resistance to abrasion decrease, measured with the mass loss of abraded (using T-07 apparatus) coating material