Physical Sciences and Mathematics Commons^™

Effect Of Network Structure On Free Volume And Gas Transport Properties Of Thiol-Ene And Epoxy-Amine Networks, Ramesh Krishnan Ramakrishnan

Dissertations

Network parameters such as cross-link density or intermolecular interactions were used as effective parameters to control polymer chain packing or free volume and thereby control the mass transport properties of networks.

A series of polyethylene glycol (PEG) based thiol-ene elastomeric networks having a broad range of molecular weight between cross-links, M_c, (inverse of cross-link density) was prepared. The specific volume of the networks was studied as a function of temperature and pressure using high pressure dilatometry, and the obtained PVT data was fit using Simha-Somcynsky equation of state (S-S eos) analysis. Fractional free volume, quantified through S-S eos …

Characterization Of Epoxy/Amine Networks With Glycidal Polyhedral Oligomeric Silsesquioxane Surface Modified Silica Nanoparticles, Reese K. Sloan

Honors Theses

Silica nanoparticles were surface modified with octa-functional glycidal polyhedral oligomeric silsesquioxane (G-POSS) and incorporated into an epoxy/amine system in an effort to increase the mechanical performance of the inorganic/organic hybrid material. The silica nanoparticles were first functionalized with 3-aminoprpyltrimethoxysilane (APTMOS) at 5 and 10 weight percent, and then modified with G-POSS at ratios of 1:10 and 1:5 (APTMOS: G-POSS). The modified particles were then incorporated into an epoxy/amine network consisting of diglycidyl ether of bisphenol A (DGEBA) and aromatic amine, diamine diphenyl sulfone (4,4’ DDS) at 1 and 5 weight percent, resulting in 8 different formulations. The incorporation of the …

Relationships Between Cure Kinetics, Network Architecture, And Fluid Sensitivity In Glassy Epoxies, Katherine Lea Frank

Dissertations

Relationships between chemical structure, cure kinetics, network morphology and free volume have been correlated with fluid ingress for glassy epoxy network blends. Polymers synthesized from diglycidyl ether of bisphenol-A (DGEBA) and diglycidyl ether of bisphenol-F (DGEBF) were blended with varying amounts of triglycidyl-m-aminophenol (TGAP), tetraglycidyl-4,4-diaminodiphenylmethane (TGMP), napthylamine (NA), adamantylamine (AA), and aminopropylisobutyl polyhedral oliogmericsilsesquioxane (AI-POSS) and cured with 3,3’- and 4,4’- diaminodiphenylsulfone (DDS) to control fractional free volume, average hole size and morphology.

Varying curing profiles introduced morphological changes resulting in differences in network architectures. Epoxy with 10% NA had a smaller V_h (71 ų) …