<p>Transport of gasses and liquids through polymers and
composites is an important factor to be considered when designing a material
for structure and packaging applications. For structural engineering
applications, more focus has been given to the transportation of water, vapor
and organic liquids rather than gases as diffusion of these liquids into the
polymers and polymer-based composites can significantly lower service life. In
addition, much attention has been given to the leaching of unreacted reactant
molecules, solvents, additives, degradation products from the polymers and
composites to the atmosphere (water, soil etc.). We studied the transport of volatile
organic compounds and water in cured-in-place-pipe (CIPP) (a representative of
FRPC) and gas permeability of highly engineered cellulose nanocrystals (CNC)
films.</p>
<p>Cured-in-place-pipe (CIPP) is a popular technology which
uses fiber reinforced polymer composite to repair sanitary sewer, stormwater,
and drinking water pipe. The liner is installed in the field and exposed to
flowing water immediately after installation (curing of the liner) is done.
Curing conditions dictate liner properties as undercured liners can contain
unreacted styrene monomers, additives, degradation products. These agents can
leach out and enter the environment (soil, water, air). The objective of this
work was to investigate the curing behavior, volatile content, thermal
stability of steam-cured and UV-cured CIPP liners collected from Indiana and
New York installation sites. The liner specimens were also exposed to water and
other aggressive environmental conditions (saltwater, concrete pore solution at
50 °C) to explore the leaching of unreacted styrene and other organic chemicals
from the liners. The influence of transportation of water, salt solution and
pore solution through liners on mechanical and thermo-mechanical properties was
also examined to study the durability of the liners. Study suggested that the
durability of the liners depends on the curing condition and exposed
environment conditions.</p>
<p>The function of polymer packaging materials is mainly to
inhibit gas and moisture permeation through the films. Cellulose nanocrystals
(CNCs) have drawn growing interest for the packaging due to their non-toxicity,
abundance in nature, biodegradability and high barrier properties. The
objective of this work was to corelate the alignment of CNC with free volume
and barrier performance of the film. Furthermore, citric acid (CA) was added to
the CNC suspensions with varying quantity to explore the effect of CA on
coating quality and barrier performance of CNC coated polypropylene (PP) film.
Study revealed that CA addition in CNC suspension can enhance the
hydrophobicity and gas barrier performance of coated PP films while retaining
the high optical transparency. </p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/12161568 |
| Date | 21 April 2020 |
| Creators | Md Nuruddin (8738436) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/Molecular_Transportation_in_Polymer_and_Composite_Materials_Barrier_Performance_and_Mechanical_Property_Evaluation/12161568 |
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