Formulações de misturas de polipropileno pos-consumo e virgem para processamento por injeção

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

This project originated from the necessity to obtain recycled polymers with quality and prices competitive with virgin resin. We chose polypropylene (PP) due to its properties, versatility and frequent use in injection moulding. The processing parameters of PP for ex:trusion were determined, verifying that the increase of the temperature profile and of the screw rotational speed affected the thermal stability and the mechanical properties. The residence time of PP in the extruder was measured (~3 min) in the determined processing conditions. Chemometry showed that there is no interaction between carbon black and Recyclostab 411® additive added to the mixture of virgin PP/post-consumer PP. The problems of carbon black dispersion in the prepared masterbatch were solved substituting it by a commercial masterbatch. Using the surface response methodology we obtained curves indicating that Oxidative-Induction Time and Melt Flow Index factors were influenced by the concentration of Recyclostab 411® and by the relative concentration of the mixture components (virgin PP/post-consumer PP); the mechanical properties was affected only by the last factor. Successive extrusions (13) produced an increase in the melt flow index and decrease in the thermo-oxidative stability of the mixture virgin PP/post-consumer PP (1:1). This effect was more pronounced in comparison to virgin PP. Addition of 0,20 % Recyclostab 411® produced a material with competitive quality in relation to granulated virgin PP with melt flow index 10 g/10min. The formulation containing 0,40 % had little variation in the properties and can be directly used for injection moulding.

ASSUNTO(S)

agentes estabilizantes plasticos

ACESSO AO ARTIGO

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