A síntese dos copolímeros propostos nessa dissertação foi satisfatória no meio aquoso, por catálise radicalar, tornando-se menos nocivo ao meio ambiente (por não usar solventes tóxicos e orgânicos). O rendimento de cada material bruto sintetizado foi de 90 % para a PNIPAAm e para os copolímeros contendo 7 e 13 mol% de LV foi de 70 e 55 %, respectivamente, alcançando bons rendimentos.
O procedimento para a polimerização visto no item 4.2 mostrou-se um método mais eficaz do que os métodos convencionais de polimerização em solução, que utilizam balões de três bocas, em atmosfera inerte.
A metodologia de purificação para a PNIPAAm por acetona à quente e em seguida o uso da diálise foi eficiente, visto que, na caracterização estrutural por FT-IR e RMN, não foram detectados picos das duplas ligações do monômero. Para o copolímero com 7 mol% de LV, a purificação também foi bastante eficiente por filtração seguida de diálise. Quanto ao copolímero com 13 mol% de LV, seria necessário uma purificação mais adequada, pois de acordo com as análises de RMN, picos das duplas ligações dos dois monômeros (NIPAAm e LV) foram detectados.
Os métodos de caracterização estrutural por FT-IR, 1H RMN e 13C RMN foram bem representativos, indicando os picos de formação dos polímeros sintetizados.
As análises térmicas mostraram que os copolímeros apresentaram boas estabilidades térmicas quando submetidos ao aquecimento.
Apesar de os polímeros não terem apresentados valores de viscosidade elevadas, eles mostraram um comportamento termoresponsivo em uma temperatura crítica, em que a viscosidade teve um súbito aumento, indicando uma LCST para cada polímero obtido e, à medida que a temperatura foi aumentada, acima da LCST, a viscosidade foi reduzida. Para a PNIPAAm foi identificada uma LCST em torno de 34 ºC e para os copolímeros contendo 7 e 13 mol% de LV a LCST foi identificada aproximadamente em 26 e 21 ºC, respectivamente.
Os resultados obtidos por DLS mostraram que o processo de agregação é afetado quando a solução de polímero é filtrada, apresentando valores e quantidades menores de agregados após a filtração. Ao avaliar o comportamento dos agregados com a variação da temperatura observou-se que os polímeros responderam sensivelmente às mudanças na temperatura apresentando mudanças na conformação da macromolécula para valores de Rh menores, indicando uma transição de fase em uma dada faixa de temperatura.
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