Preparation and characterization of mono-component two-phase system (SBM) by oxypropylation reaction of cellulose fibres and starch / Preparação e caracterização de sistema bifásico mono-componente (SBM) a partir da reação de oxipropilação de fibras celulósicas e amido

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Chemical modifications were applied to cellulosic materials and starch with the objective to obtain products with an external thermoplastic layer while preserving the inner part of these substrates. The final products should behave as composite materials where the unmodified inner part is the reinforcement agent and the thermoplastic layer the matrix. The modifications were performed by grafting polypropylene oxide short chains to the polysaccharide backbone (cellulose and starch). The grafted polypropylene oxide chains will render a thermoplastic layer around the unmodified polysaccharide portions. The attainment of these materials can excuse the stages of mixture and allow the thermal processing without the necessity of use the second component (matriz), a time that the proper polymeric layer would play this role. The construction of the involving polymeric layer was conducted by reacting pre-activated cellulose (or starch) and propylene oxide (PO). The activation step was performed with KOH (or DABCO) treatment and the grafting reaction was carried through in heterogeneous system. The materials obtained following these treatments were characterized by different techniques (FTIR, X-Ray, MEV, TG, DSC, Contact Angle and Mechanical Analyses). The results had demonstrated that it is possible to produce materials with strengthened thermoplastic characteristics through the reaction in an only stage, without the necessity of laborious synthetic procedures.

ASSUNTO(S)

oxypropylation reaction mono-component composite fibras de celulose starch cellulose fibres compósito mono-componente amido reação de oxipropilação

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