Caracterização de quitosana em ácido pirolenhoso destilado com potencial uso como coberturas protetoras

Chitosan acid films can be used as coatings for vegetal tissues due to their antifungal and antimicrobial properties and, also, can act as an antiperspirant.Chitosan in pyroligneous distilled acid had been characterized comparatively to systems of this polymer in acetic acid 2 % (v/v). It was evaluated pH, conductivity, thermal behavior, molecular weight, gyration radio and second virial coefficient and rheological behavior. Auto supported films, obtained from chitosan in acetic acid, were evaluated with respect to the protection against the ultraviolet/visible radiation, resistance to water immersion, swelling degree and thermal degradation. The pyroligneous distilled acid is better solvent for this polymer comparatively to acetic acid solution. Chitosan, in both solvents, presented Newtonian behavior in the range of temperature from 10 to 40 °C at studied range of concentration and the system is thermally stable in the range of temperature from -40 to 60 °C. Films increased around 400 % of their weight, when immersed in water, being stable up to than seven days. Although a small loss of water under heating occurred, films are thermally stable up to 300 °C. The films block radiation efficiently UV-C (279-200 nm) and part of UV-B (319-280 nm), being able to be used as photo protectors. The molar absorptivity diminishes exponentially with the increasing of wavelength, these results show it is possible to obtain coating with different thicknesses to produce the desired protection against UV radiation. The films of chitosan in pyroligneous distillate acid will not be discussed in this paper.Filmes ácidos de quitosana podem ser usados como coberturas para tecidos vegetais devido as suas propriedades antifúngicas e antimicrobianas, podendo atuar também como anti-transpirante. Neste trabalho soluções de quitosana em ácido pirolenhoso destilado foram caracterizadas em solução comparativamente às soluções de quitosana em ácido acético a 2 % (v/v). Foram avaliados pH, condutividade, comportamento térmico, massa molar, raio de giro, segundo coeficiente virial e propriedades reológicas. Foram obtidos também filmes auto suportados de quitosana em ácido pirolenhoso destilado e em solução de ácido acético a 2 % (v/v) que foram avaliados em relação à proteção contra as radiações ultravioleta/visível, resistência à água, inchamento e degradação térmica. O ácido pirolenhoso destilado mostrou ser melhor solvente para este polímero comparativamente à solução de ácido acético. A quitosana, nos dois solventes estudados, apresentou comportamento newtoniano na faixa de temperatura de 10 a 40 °C na faixa de concentrações estudada e as soluções são termicamente estáveis na faixa de temperatura de -40 a 60 °C. Os filmes de quitosana em solução de ácido acético absorveram mais de 400 % de sua massa em água e são estáveis sob imersão por mais de sete dias. Apesar de uma pequena perda de água sob aquecimento, os filmes são termicamente estáveis até 300 °C e bloqueiam a radiação UV-B (319-280 nm) e UV-C (279-200 nm), podendo ser usados como fotoprotetores. A absortividade molar diminui exponencialmente com o comprimento de onda, estes resultados permitem a formulação de filmes com diferentes espessuras de acordo com a proteção UV desejada. Os filmes de quitosana em ácido pirolenhoso destilado não serão discutidos neste trabalho

Distilled pyroligneous liquor obtained from Eucalyptus grandis and chitosan : physicochemical properties of the solution and films

The pyroligneous liquor is a product obtained during the production of charcoal, with well-known antimicrobial activity. In this work, we characterized the physical chemistry properties of a formulation composed of distilled pyroligneous liquor (DPL), obtained from Eucalyptus grandis, and chitosan. A good interaction between the polymer and the solvent was observed. Auto-supported films were prepared with these systems and characterized with respect to their structure and photo-protection properties, water vapor permeability, and resistance to water and to thermal degradation. They present a semi-crystalline structure and are hygroscopic, but are stable under immersion for up to 7 days. The swelling degree in water is 300% in weight and the permeability to water vapor was between 30 and 45 gm−1 h−1 (for films with 80 to 10 μm, respectively). The obtained films are able to efficiently block the incident UVB and UVC radiation; the molar absorptivity decreases exponentially with increasing wavelength and is stable up to 300 °C. These properties confer desirable properties to the films, obtained from these precursors of a renewable source, to be used as coatings

Distilled pyroligneous liquor obtained from Eucalyptus grandis and chitosan : physicochemical properties of the solution and films

The pyroligneous liquor is a product obtained during the production of charcoal, with well-known antimicrobial activity. In this work, we characterized the physical chemistry properties of a formulation composed of distilled pyroligneous liquor (DPL), obtained from Eucalyptus grandis, and chitosan. A good interaction between the polymer and the solvent was observed. Auto-supported films were prepared with these systems and characterized with respect to their structure and photo-protection properties, water vapor permeability, and resistance to water and to thermal degradation. They present a semi-crystalline structure and are hygroscopic, but are stable under immersion for up to 7 days. The swelling degree in water is 300% in weight and the permeability to water vapor was between 30 and 45 gm−1 h−1 (for films with 80 to 10 μm, respectively). The obtained films are able to efficiently block the incident UVB and UVC radiation; the molar absorptivity decreases exponentially with increasing wavelength and is stable up to 300 °C. These properties confer desirable properties to the films, obtained from these precursors of a renewable source, to be used as coatings

Processo de obtenção de formulação com capacidade fertilizante e fitoprotetora, formulação com capacidade fertilizante e fitoprotetora, uso de formulação com capacidade fertilizante e fitoprotetora

Empresa Brasileira de Pesquisa AgropecuáriaUniversidade Federal do Rio Grande do SulQuímicaDepositad