Publicação
A look inside the extruder: evolution of chemistry, morphology and rheology along the extruder axis during reactive processing and blending
| Resumo: | A simple device was recently developed for fast sampling (within a few seconds) of representative melt samples (about 2 g) on a running extruder. An array of such devices has been mounted on a twin-screw extruder. The goal of this study was to de-black-box reactive processing of polymers by studying some typical examples.Processing of polyolefins in the presence of peroxides: when the polymer is molten and the melt temperature is sufficiently high branching/cross-linking of PE and degradation of PP occurs; the conversion follows a convex profile along the screw axis, which profile is similar to the exponential profile calculated for peroxide decomposition.Free-radical grafting of maleic anhydride (MA) onto polyolefins: MA grafting onto PE and PP also follows a convex profile with branching/cross-linking as parallel side reaction for PE and degradation for PP; for PE degradation of the formed grafted/cross-linked gel is observed at the end of the extruder.Reactive blending of PA-6 with EPM-g-MA: within a few seconds the in-situ compatibilization reaction, resulting in PA-6/EPM graft copolymers, is completed and the degree of rubber dispersion has changed from the mm to the sub-mum range, regardless of the MA content of EPM-g-MA and the EPM-g-MA content of the blend; PA degradation occurs along the whole extruder. |
|---|---|
| Autores principais: | van Duin, Martin |
| Outros Autores: | Machado, A. V.; Covas, J. A. |
| Ano: | 2001 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | A simple device was recently developed for fast sampling (within a few seconds) of representative melt samples (about 2 g) on a running extruder. An array of such devices has been mounted on a twin-screw extruder. The goal of this study was to de-black-box reactive processing of polymers by studying some typical examples.Processing of polyolefins in the presence of peroxides: when the polymer is molten and the melt temperature is sufficiently high branching/cross-linking of PE and degradation of PP occurs; the conversion follows a convex profile along the screw axis, which profile is similar to the exponential profile calculated for peroxide decomposition.Free-radical grafting of maleic anhydride (MA) onto polyolefins: MA grafting onto PE and PP also follows a convex profile with branching/cross-linking as parallel side reaction for PE and degradation for PP; for PE degradation of the formed grafted/cross-linked gel is observed at the end of the extruder.Reactive blending of PA-6 with EPM-g-MA: within a few seconds the in-situ compatibilization reaction, resulting in PA-6/EPM graft copolymers, is completed and the degree of rubber dispersion has changed from the mm to the sub-mum range, regardless of the MA content of EPM-g-MA and the EPM-g-MA content of the blend; PA degradation occurs along the whole extruder. |
|---|