Blendas de poli (metacrilato de metila-co-metacrilato de glicidila) e poli (butadieno-co-acrilonitrila)

AUTOR(ES)

Luis Eduardo Pais dos Santos

DATA DE PUBLICAÇÃO

1995

RESUMO

Blends of poly(butadiene-co-acrylonitrile) (NBR) and poly(methyl methacrylate-co-glycidil methacrylate) P(MMA-co-GMA) were prepared aiming analysing its phase behavior and characterizing these materiaIs by their structural, thermal mechanical thermo-mechanical and morphological properties as a function of NBR composition and crosslinking degree. P(MMA-co-GMA) copolymer was obtained by radical chain polymerization in solution. Commercial NBR containing 16% (NBR-16), 29% (NBR-29) and 45% (NB R-45) weight/weight of acrylonitrile were used. Blends of NBR-16 and NBR-29 with P(MMA-co-GMA) were obtained by freeze drying of solulions in benzene; while blends of NBR-45 were obtained by precipitation of solutions. The blends composition were 25,50,75 and 90% by weight of rubber. In a group of samples of each composition, NBR was vulcanized and in another group the acrylic phase was cross-linked with p- phenylenediamine (PFD), besides vulcanization. Samples were characterized by thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), swelling and extraction measurements, dynamic-mechanical analysis (DMA), tensile properties and scanning eletron microscopy (SEM). No miscibility was verified by DSC and DMA for all compositions. It was observed by TGA that thermal stability of P(MMA-co-GMA) increase with crosslinking. It was observed by swelling measurements the sol fraction is strongly dependent on the composition of NBR (percentage af acrylonitrile), the blends composition (weight % of NBR) and the methacrylic phase crosslinking. This dependente suggests that the phases are co-continuous in blends NBR-16/ P(MMA-co-GMA) and NBR-45/P(MMA-co-GMA). In the NBR-29/P(MMA - co-GMA) blend the methacrylic phase is dispersed in the rubber matrix. DMA tests and mechanical behavior confirm this hypothesis. Finally, mechanical tests showed that their behavior depends on concentration of P(MMA-co-GMA). The relationship between the methacrylic phase crosslinking degree and the mixtures mechanical properties gave information about morphology.

ASSUNTO(S)

mistura (quimica) polimeros

Documentos Relacionados

• Sintese, estrutura-morfologia e relação com propriedades macroscopicas do modificador de impacto poli (metacrilato de metila-co-butadieno-co estireno), MB&
• Blendas de poli(epicloridrina) e poli(estireno-co-metacrilato de metila)
• Síntese e caracterização de microesferas porosas de poli(estireno-co-divinilbenzeno-co-metacrilato de glicidila)
• Modificação do poli (metacrilato de metila) com poli (epicloridrina-co-oxido de etileno)
• Tenacificação do poli(ácido lático) pela adição do terpolímero (etileno/acrilato de metila/metacrilato de glicidila)