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Visar resultat 1 - 5 av 11 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Investigation of the functionality related characteristics of hydroxypropyl methylcellulose for the release from matrix tablets

    Författare :Anna Viridén; Chalmers tekniska högskola; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; functionality related characteristics; batch-to-batch variation; hydrophilic matrix tablets; hydroxypropyl methylcellulose; polymer characterisation; heterogeneous; drug release;

    Sammanfattning : Hydrophilic matrix tablets are a compressed well mixed composite of drug substance and excipients including a hydrophilic polymer. When the tablet comes in contact with biological fluids, the hydrophilic polymer starts to dissolve, a process that decreases the water penetration through the tablet and involves dimensional changes of the tablet due to swelling of the solvated polymers. LÄS MER

  3. 2. Foaming of cellulose derivatives and hemicellulose-containing materials

    Författare :Kristina Karlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; β-glucan; arabinoxylan; scale-up production; hydroxypropyl methylcellulose HPMC ; ethyl hydroxyethyl cellulose EHEC ; hot-mould foaming; extensional viscosity; extrusion; hemicellulose; rheological characterisation; Foaming; xylan; cellulose derivatives;

    Sammanfattning : Fossil-based polymeric foams are important materials due to their good mechanical properties relative their low density, the low price and the possibility for large-scale production. They are widely used in cushioning, absorbing and insulation applications. There are however a few disadvantages with these foamed products. LÄS MER

  4. 3. Foaming of Some Cellulose Derivatives - Initial Studies

    Författare :Kristina Karlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rheological characterisation; Foaming; hydroxypropyl methylcellulose HPMC ; scale-up production; ethyl hydroxyethyl cellulose EHEC ; hot-mould baking; cellulose derivatives; extrusion;

    Sammanfattning : Fossil-based polymeric foams, based on polymers such as polystyrene and polyurethane, are important and widely employed materials due to their good mechanical properties relative their low density, the low price and the possibility for large-scale production. There are however a few disadvantages with these foamed products. LÄS MER

  5. 4. Heterogeneities in polymer gels: Effects on swelling and mechanical properties

    Författare :Mikael Larsson; Chalmers tekniska högskola; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Gel; Phase separation; Heterogeneities; Polyacrylic acid.; HPMC; Glass transition temperature; Microfibrillated cellulose; Filler; Elastomer;

    Sammanfattning : Polymeric hydrogels is a class of scientifically interesting materials that are being extensively studied. They are found in numerous applications within; drug delivery, hygiene products, food industry, analytical chemistry, etc. In addition, polymeric hydrogels have promising future applications as; cell scaffolds, implants, sensors, etc. LÄS MER

  7. 5. Dissolution of Polydisperse Polymers in Water

    Författare :Anna Körner; Fysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysikalisk kemi; Physical chemistry; PEO; swelling; polymer dissolution; polydispersity;

    Sammanfattning : The different steps in the dissolution process of polydisperse polymers in water have been studied. To that end, poly(ethylene oxide), dextran and hydroxypropyl methylcellulose tablets varying widely in polydispersity have been produced by mixing low molecular weight and high molecular weight samples in different proportions. LÄS MER