Cílem diplomové práce je studium krystalizace a morfologie polypropylenu s dlouhými bočními větvemi (LCB-PP) za zvýšeného tlaku. Zavedení dlouhých bočních větví na kostru polypropylenu (PP) vede ke zvýšení pevnosti taveniny a materiál je vhodnější pro zpracovatelské procesy jako tvarování, zpěňování a vyfukování. LCB-PP má větší tendenci krystalizovat do {γ}-formy pod tlakem. V této práci byly podrobeny krystalizaci pod různými tlaky materiály LCB-PP, lineární PP s podobným indexem toku taveniny, a také PP o velmi vysoké čistotě zbavený katalytických zbytků.
Struktura uvedených materiálů byla v práci zkoumána pomocí širokoúhlé rentgenografie, diferenciální snímací kalorimetrie, skenovací elektronové mikroskopie a mechanické vlastnosti byly stanoveny tlakovou zkouškou. Byla potvrzena zvýšená tendence tvorby {γ}-fáze u LCB-PP.
Annotation in English
The aim of the Master thesis is to study crystallization and morphology of long chain branched polypropylene (LCB-PP) under increased pressure. The introduction of long chain branching onto polypropylene (PP) backbone leads to improvement of melt strength ant thus the material is suitable for otherwise limiting processing such as thermoforming, foaming and blow molding. LCB-PP has higher tendency to form orthorombic {γ}-form under pressure. In this work LCB-PP, common linear PP with similar melt flow index and also PP which was cleaned to eliminate catalyst residues were crystallized under several pressures.
Than, the structure was evaluated via several methods, namely wide angle X-ray scattering, differential scanning calorimetry, scanning electron microscopy. Mechanical properties were determined via compressive testing. The higher tendency to crystallize into {γ}-form in LCB-PP was proved.
high pressure crystallization, long chain branched polypropylene, wide angle X-ray scattering, differential scanning calorimetry, scanning electron microscopy, compressive testing
Length of the covering note
81 s., 2 s. obr. příloh.
Language
CZ
Annotation
Cílem diplomové práce je studium krystalizace a morfologie polypropylenu s dlouhými bočními větvemi (LCB-PP) za zvýšeného tlaku. Zavedení dlouhých bočních větví na kostru polypropylenu (PP) vede ke zvýšení pevnosti taveniny a materiál je vhodnější pro zpracovatelské procesy jako tvarování, zpěňování a vyfukování. LCB-PP má větší tendenci krystalizovat do {γ}-formy pod tlakem. V této práci byly podrobeny krystalizaci pod různými tlaky materiály LCB-PP, lineární PP s podobným indexem toku taveniny, a také PP o velmi vysoké čistotě zbavený katalytických zbytků.
Struktura uvedených materiálů byla v práci zkoumána pomocí širokoúhlé rentgenografie, diferenciální snímací kalorimetrie, skenovací elektronové mikroskopie a mechanické vlastnosti byly stanoveny tlakovou zkouškou. Byla potvrzena zvýšená tendence tvorby {γ}-fáze u LCB-PP.
Annotation in English
The aim of the Master thesis is to study crystallization and morphology of long chain branched polypropylene (LCB-PP) under increased pressure. The introduction of long chain branching onto polypropylene (PP) backbone leads to improvement of melt strength ant thus the material is suitable for otherwise limiting processing such as thermoforming, foaming and blow molding. LCB-PP has higher tendency to form orthorombic {γ}-form under pressure. In this work LCB-PP, common linear PP with similar melt flow index and also PP which was cleaned to eliminate catalyst residues were crystallized under several pressures.
Than, the structure was evaluated via several methods, namely wide angle X-ray scattering, differential scanning calorimetry, scanning electron microscopy. Mechanical properties were determined via compressive testing. The higher tendency to crystallize into {γ}-form in LCB-PP was proved.
high pressure crystallization, long chain branched polypropylene, wide angle X-ray scattering, differential scanning calorimetry, scanning electron microscopy, compressive testing
Research Plan
The aim of this Master thesis is to study crystallization of long chain branched polypropylene (LCB PP) under increased pressure. The introduction of long chain branching onto polypropylene backbone leads to improvement of melt strength ant thus the material is suitable for otherwise limiting processing such as thermoforming, foaming and blow molding. However, the change of molecular architecture can affect not only rheological properties but also crystallization of PP. Moreover, the pressure which is often applied during processing can play an important role as it causes the crystallization into orthorhombic {γ}-phase. This polymorph of isotactic polypropylene processes different physical properties than common monoclinic {α}-phase, e. g. lower opacity.
In the work, LCB PP and also standard PP will be crystallized under several pressures. Than, the structure will be evaluated via several methods such as X-ray scattering, differential scanning calorimetry, optical microscopy and scanning electron microscopy and mechanical properties testing.
Research Plan
The aim of this Master thesis is to study crystallization of long chain branched polypropylene (LCB PP) under increased pressure. The introduction of long chain branching onto polypropylene backbone leads to improvement of melt strength ant thus the material is suitable for otherwise limiting processing such as thermoforming, foaming and blow molding. However, the change of molecular architecture can affect not only rheological properties but also crystallization of PP. Moreover, the pressure which is often applied during processing can play an important role as it causes the crystallization into orthorhombic {γ}-phase. This polymorph of isotactic polypropylene processes different physical properties than common monoclinic {α}-phase, e. g. lower opacity.
In the work, LCB PP and also standard PP will be crystallized under several pressures. Than, the structure will be evaluated via several methods such as X-ray scattering, differential scanning calorimetry, optical microscopy and scanning electron microscopy and mechanical properties testing.
Recommended resources
1. Karger-Kocsis, J.: Polypropylene - An A-Z Reference, Springer - Verlag, 1999, ISBN: 0-412-80200-7 2. Maier, C.; Calafut, T.: Polypropylene - The Definitive User's Guide and Databook, William Andrew
Publishing/Plastics Design Library, 1998, ISBN: 1-884207-58-8
and scientific articles
Recommended resources
1. Karger-Kocsis, J.: Polypropylene - An A-Z Reference, Springer - Verlag, 1999, ISBN: 0-412-80200-7 2. Maier, C.; Calafut, T.: Polypropylene - The Definitive User's Guide and Databook, William Andrew
Publishing/Plastics Design Library, 1998, ISBN: 1-884207-58-8
and scientific articles
