Sökning: "chain scission"
Visar resultat 1 - 5 av 11 avhandlingar innehållade orden chain scission.
1. Cellulose degradation in pulp fibers studied as changes in molar mass distributions
Sammanfattning : In this thesis, size-exclusion chromatography (SEC) of woodpolymers dissolved in lithium chloride/N,N-dimethylacetamide(LiCl/DMAc) has been used to characterize the molar massdistributions (MMD) of wood polymers in pulp fibers afterchemical degradation.Characterization of birch kraft pulps subjected to ozonedegradation and acid hydrolysis, respectively, rendereddifferent changes in the MMD. LÄS MER
2. Plasma Modification of Polypropylene Materials for Improved Adhesion
Sammanfattning : Materials based on PP are widely used in industrial applications. To fulfil application demands, components must often be lacquered, printed or glued. As PP is highly unreactive and presents a low surface energy, a pretreatment that can promote bondability is necessary. LÄS MER
3. Modification of stable and degradable polymers by heterogeneous grafting
Sammanfattning : This thesis summarizes the investigations of the electronbeam initiated grafting of a hydrophilic monomer, acrylamide(AAm), onto three polymers; linear low density poly(ethylene)(LLDPE), poly(&-caprolactone) (PCL) and chemicallycrosslinked poly( 1,5-dioxepan-2-one) (PDXO-X). LLDPE and PCLare semicrystalline and PDXO-X is fully amorphous. LÄS MER
4. Modelling the degradation processes in high-impact polystyrene during the first use and subsequent recycling
Sammanfattning : Polymers are subjected to physical and chemical changes during their processing, service life, and further recovery, and they may also interact with impurities that can alter their composition. These changes substantially modify the stabilisation mechanisms and mechanical properties of recycled polymers. LÄS MER
5. Utilizing lignocellulose-based building blocks to develop recyclable polyesters
Sammanfattning : With the growing global population and the demand for new applications, the production of fossil-based plastics is continuously increasing. This has led to serious environmental concerns about the depletion of fossil resources, land and marine pollution, and generation of greenhouse gas emissions. LÄS MER