Search for dissertations about: "polyethylene pipes"

Showing result 1 - 5 of 10 swedish dissertations containing the words polyethylene pipes.

2. 1. Degradation of polyethylene pipes distributing chlorinated water : depletion of stabilizers, release of degraded products and polymer degradation

   Author : Wenbin Yu; Ulf Gedde; Mats Jonsson; Minna Hakkarainen; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; polyethylene pipes; chlorine dioxide; degradation; Polymer chemistry; Polymerkemi;

   Abstract : This thesis presents the study of antioxidants depletions in chlorinated media (10 ppm Cl2 - and ClO2 - aqueous media), polyethylene pipes degradations scenarios and migration of the degraded species to aqueous phase. Pressure testing on pipes and squalane testing with controlled pH aqueous media (6.8 ± 0. READ MORE

4. 2. Durability of District Heating Pipes

   Author : Stefan Forsaeus Nilsson; RISE; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reuse of excavated material; district heating pipe; moisture diffusion; pipe joint; stone indentation; polyurethane foam; polyethylene; district heat distribution; long-term strength; buried pipe;

   Abstract : This thesis is focused on mechanical loads and moisture related problems with a potential to critically harm the functionality of pre-insulated district heating pipes and pipe joints. Directly buried pipeline bends are investigated with respect to limiting deformations from a thermally induced lateral displacement. READ MORE

5. 3. Deterioration of Polyethylene Exposed to Chlorinated Species in Aqueous Phases : Test Methods, Antioxidants Consumption and Polymer Degradation

   Author : Wenbin Yu; Ulf Gedde; Sahar Al-Malaika; KTH; []
   Keywords : Antioxidants; Polyethylene pipes; Chlorine dioxide; Degradation;

   Abstract : This thesis presents a study of antioxidant depletion in water containing chlorinated species (water containing 10 ppm either Cl2 or ClO2, buffered to pH = 6.8), the degradation products in the aqueous phase, and polyethylene pipe degradation scenarios. READ MORE

6. 4. The influence of Morphology on the Transport and Mechanical Properties of Polyethylene

   Author : Bereket Neway; KTH; []
   Keywords : n-hexane diffusion; polyethylene; free volume; solubility; sorption; desorption; mechanical properties; orientation; thermal properties; blend;

   Abstract : The sorption/desorption behaviour of n-hexane in high molarmass linear polyethylene (PE) and branched PEs with 0.39 and5.09 hexyl branches per 100 main chain C atoms andcrystallinities between 4 and 82% at 298 K has been studied.Crystal core contents determined by Raman spectroscopy werealways lower than those determined by density measurements. READ MORE

7. 5. Longterm performance of polyolefins in different environments including chlorinated water: antioxidant consumption and migration and polymer degradation

   Author : Marie Lundbäck; Ulf Gedde; Thomas Hjertberg; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical engineering; polyethylene; polybutylene; HDPE; LLDPE; phenolic antioxidants; oxidation induction time OIT ; migration; chlorinated water; pressure testing; lifetime; chemical consumption.; Kemiteknik; Chemical engineering; Kemiteknik;

   Abstract : The long-term performance of stabilized polyolefins in different environments was studied with focus on antioxidant consumption and migration. Plaques of linear polyethylene (LPE) and branched polyethylene (BPE) were stabilized with Santonox® R (4,4'-Thiobis(6-tert-butyl-3-methylphenol)), Irganox® 1081 (2,2’-Thiobis(4-methyl-6-tertbutylphenol)), or Lowinox® 22M46 (2,2’-Methylenebis(6-tert-butyl-4-methylphenol)). READ MORE