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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Dynamic mechanical thermal properties of moulded poly(vinylchloride) swollen with organic liquids

Hovell, Ian January 1987 (has links)
Compression-moulded unplasticised poly(vinylchloride) (uPVC) was swollen with various organic liquids at two temperatures, 60°C and 30°C, both temperatures being below the glass transition temperature of uPVC. Liquids were chosen to give a range of solubility parameters, molecular sizes and ability to form hydrogen bonds. It was hoped to find a PVC–liquid system which behaved similarly to PVC swollen with vinyl chloride monomer (VCM).
2

A Laboratory Scale Study of Particulates Generation from Charring and Non-Charring Polymers

Wen, Chenran 23 May 2019 (has links)
No description available.
3

SURFACE MODIFICATION OF PVC/PU FOR ENHANCED BIOFOULING RESISTANCE

Rashed Abdulaziz R Almousa (6640046) 10 April 2023 (has links)
<p>Medical devices are at risk of biofouling within seconds after implantation, which can lead to thrombus formation and bacterial contamination. These issues can negatively impact the performance and reliability of the device. Poly(vinyl chloride) (PVC) and polyurethane (PU) are popular synthetic polymers used in biomedical applications, but their hydrophobic nature makes them susceptible to biofouling. To improve their biocompatibility, their surfaces must be modified to be antifouling. However, achieving a thoroughly coated surface through homogeneous activation and effective modification with antifouling polymers remains a challenge, despite recent advancements in polymer surface modification. In this dissertation, we modified the surfaces of medical-grade PVC and PU using hydrophilic and biocompatible polymer brushes via wet chemistry approaches in an aqueous medium. Specifically, we activated the PVC surface with amino groups and then modified it with either modified or synthesized hydrophilic polymers end-capped with reactive groups. Additionally, we coupled a functionalized surface initiator to the activated PVC surface to allow the grafting of different hydrophilic polymers via conventional <em>in situ</em> free-radical polymerization. We followed a similar process to activate the PU surface with amino groups and then coupled a co-initiator derivative to allow the grafting of different hydrophilic polymers via conventional <em>in situ</em> free radical polymerization as a redox initiation system. All the modified surfaces of PVC and PU have exhibited a significant increase in wettability, as well as extremely effective antifouling effects against cell and bacterial adhesion. Overall, the findings of this work demonstrate the applicability of wet chemistry surface modification for PVC- or PU-based medical devices and supplies in biofouling-resistant applications. </p>
4

Observing the Main Effects of Automotive Primers when Bonding to Polyvinylchloride

Javorsky, Joseph Frank January 2012 (has links)
No description available.
5

Vliv směsí "Green solvents" a nanočástic na vybrané polymerní povrchové úpravy / Influence of „Green solvents“ and nanoparticles mixtures on select polymeric surface finishing.

Trhlíková, Lucie January 2012 (has links)
This work is aimed to the study of mixtures of solvents type "green" and nanoparticles in direct interaction with selected polymeric surface treatment. The values in question are resistance of surface treatment to effect of solvent mixtures with additions of nanoparticles agents and removability of selected impurities from coating layers of polyvinyl chloride, polyurethane and polyester by solvents of the basis of mixed esters.
6

A Study of Electricians' Preferences of PVC and Alternative Conduit Materials in the State of Utah

Andrus, Robert 30 November 2009 (has links) (PDF)
Polyvinyl Chloride, commonly known as PVC is a common and effective construction material. PVC is also one of the most common types of plastic. In 2008, global production and consumption of PVC was approximately 34.5 million tons. The construction industry is responsible for about 70% of the world's consumption of PVC. The largest construction use of PVC is for pipe and conduit. Modern construction, especially structures built for data services depend heavily upon PVC conduit for underground pathways to distribute electricity and data. PVC is also at the center of a fierce effort by environmental groups who would like to see it eliminated completely. If environmentalists are successful in their efforts to eliminate PVC; builders will be left without a material that is crucial for many applications. Seven alternative conduit materials have been identified as potential replacements for PVC electrical conduit. PVC electrical conduit is commonly used in commercial, industrial, and civil construction. This thesis undertook to study the four major electrical contractors in the state of Utah which employ more than one hundred electricians. Because major electrical contractors use large quantities of PVC conduit, electricians working for these contractors were surveyed to determine their preferences of alternative materials. A questionnaire was distributed and received 112 responses, which represent 6.5% of the total population. This study found that PVC was the most used, most preferred, easiest to install and was perceived as the least expensive conduit material. Polypropylene and High Density Polyethylene were rated next highest, but were also the least commonly used of the alternative materials. The other materials, which include: Nylon, Fiberglass, Fiberglass Reinforced Epoxy, Polyurethane Coated Steel, and Galvanized Steel were also examined. Many of the respondents expressed displeasure by the effort to eliminate PVC and the vast majority felt that green certification for construction did not justify elimination. These responses indicate that more needs to be done to introduce alternative conduit materials to users of PVC and educate them about the value of the alternatives. This study represents an important step in evaluating the value of PVC conduit and its alternatives.
7

Adhesion of Injection Molded PVC to Silane Primed Steel

Shah, Pranjal Kiran 26 September 2005 (has links)
No description available.

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