Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"pMDI"”.
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Species Dependence of pMDI/Wood Adhesion
Polymeric methylenebis(phenylisocyanate) (pMDI) has increasingly been used in the wood particulate composite industry. Wood composites, especially oriented strand board (OSB) are made with many variations of wood species. Little research has been done to investigate how pMDI adhesion has been …
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Molecular investigation of the wood/pMDI adhesive bondline
Polymeric diphenylmethane diisocyanate, pMDI, has become an important wood binder in recent years, due to its excellent performance in wood-based composites. However, much still remains unknown about the nature of their bonding mechanism. This research describes efforts to learn more molecular …
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Characterizing the Durability of PF and pMDI Adhesive Wood Composites Through Fracture Testing
… of phenol-formaldehyde (PF) and isocyanate (pMDI) adhesives was compared using a 2-hour boil test and an environmental test. The feasibility of using oriented strandboard (OSB), oriented strand lumber (OSL) and parallel strand lumber (PSL) for the DCB fracture method was assessed. The …
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Wood/Polymeric Isocyanate Resin Interactions: Species dependence
… of polymeric diphenylmethane diisocyanate (PMDI) resin is known to be highly dependent on the wood species. This species dependence may be due to differences in: cure chemistry, interphase morphology, or both of these factors. This study addresses aspects of the cure chemistry and interphase …
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Studies of PF Resole / Isocyanate Hybrid Adhesives
… and polymeric diphenylmethane diisocyanate (PMDI) are two commonly used exterior thermosetting adhesives in the wood-based composites industry. There is an interest in combining these two adhesives in order to benefit from their positive attributes while also neutralizing some of the negative …
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Characterization of the wood/isocyanate bondline
Polymeric diphenylmethane diisocyanate, pMDI, is a wood adhesive that provides excellent composite board properties. Much is unknown about the specific mechanism of pMDI/wood adhesion under conditions that are typical of wood gluing operations. The present research describes the use of ¹⁵N …
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Characterization of PF Resol/Isocyanate Hybrid Adhesives
… polymeric methylenebis(phenylisocyanate), pMDI, are the two primary choices for the manufacture of exterior grade wood-based composites. This work addresses simple physical blends of pMDI dispersed in PF as a possible hybrid wood adhesive. Part one of this study examined the morphology of …
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Psychological and neuropsychological correlates of Postconcussional Disorder
… of the Personality Assessment Inventory (PMDI), based the scoring of the Brief Symptom Inventory Positive Symptom Distress Index. Postconcussive symptoms were moderately correlated with PMDI scores and with specific scales on the PAI (anxiety, anxiety related disorders, depression, somatic …
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Aspects of Wood Adhesion: Applications of 13C CP/MAS NMR and Fracture Testing
… Formaldehyde (PF) and polymeric isocyanate (pMDI) are the two main types of adhesives used in the production of structural wood-based composites. Much is unknown about various aspects of adhesion between these two types of resins and wood. The present research describes the development of …
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Investigating the Surface Energy and Bond Performance of Compression Densified Wood
… and polymeric diphenylmethane diisocyanate (pMDI) were the two different adhesives used to bond fracture samples. Hygro-thermal samples bonded with PF-film had significantly higher fracture toughness than control samples, while no difference was found for densified samples. Densified samples …
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The Physical Chemistry of pMDI Formulations Derived from Hydrofluoroalkane Propellants. A Study of the Physical Behaviour of Poorly Soluble Active Pharmaceutical Ingredients; Bespoke Analytical Method Development Leading to Novel Formulation Approaches for Product Development.
… purpose is the pressurised metered dose inhaler (pMDI) whereby drugs are formulated in a volatile propellant held under pressure. The compound is aerosolised to a respirably sized dose on actuation, subsequently breathed in by the user. The use of hydrofluoroalkanes (HFAs) in pMDIs since the …
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An Improved Method for the Fracture Cleavage Testing of Adhesively-Bonded Wood
… two polymeric diphenylmethane diisocyanate (pMDI) adhesives and one polyurethane adhesive. Typical maximum SERR values were 160 and 130 J/m2 for the pMDI adhesives and 160 J/m2 for the polyurethane adhesive. A third study investigated the effect of loading rates on a cross-linked polyvinyl …
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The relationship between clinical trial participation and inhaler technique errors in asthma and COPD patients
… were: failure to exhale completely prior to pMDI activation and inhalation (49.6%), failure to perform a slow, deep inhalation following device activation (48.7%), and failure to perform a breathhold at the end of inspiration (47.3%). The risk of a critical error was higher in COPD patients …
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Fundamental Analysis of Wood Adhesion Primers
… in N-methylpyrrolidone (solution referred to as "pMDI"). The experimental system was red oak (Quercus rubra) bonded with a moisture-cure polyurethane adhesive (PUR). The objective was to document wood rheological changes induced by the three primers, and determine if these changes correlated to …
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Structure-property relationships of lignin-based isocyanate and amine adhesives for wood
… with polymeric methylene diphenyl diisocyanate (PMDI) and hexamethoxy-methyl-melamine (HMMM) to form polyurethane and polyether wood adhesives respectively. Adhesive performance in shear block tests indicated: (a) that the combination of lignin and PHDI reduced the adhesive strength shown by neat …
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Stable submicron protein particles : formation, properties, and pulmonary applications
… (HFA) for pressurized metered dose inhaler (pMDI) delivery. The flocculated rods are templated by atomized HFA droplets that evaporate and shrink to form particles with optimal aerodynamic diameters for deep lung delivery. Fine particle fractions of 38-48% were achieved. This novel concept …
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Development and use of a discrete element model for simulating the bulk strand flow in a rotary drum blender
… (OSB). Because of their increased dependency on pMDI-resins, this percentage is likely greater for oriented strand lumber (OSL) and laminated strand lumber (LSL). The cost of PF- and pMDI-resins is expected to face upward pressure as the cost of their primary constituents, natural gas and crude …
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Moisture-Cure Polyurethane Wood Adhesives: Wood/Adhesive Interactions and Weather Durability
… polymeric methylenebis(phenylisocyanate) (pMDI) resin; this was used for the solid-state NMR characterization of isocyanate cure chemistry in wood bondline. MPUR and a CPUR were employed to investigate whether wood/adhesive interactions influence PUR properties. Wood interactions …
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Strengthening of timber beams using externally-bonded sprayed fibre reinforced polymers
… borne preservative such as Borocol, while a pMDI adhesive such as AtPrime 2 is recommended for timber treated with an oil borne preservative such as Creosote. For Non Creosoted beams, adhesives did not generate as significant of a strength gain. For Creosoted beams, adhesives may be …
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Structural Determination of Copolymers from the Cross-catalyzed Reactions of Phenol-formaldehyde and Polymeric Methylenediphenyl Diisocyanate
… by the cross- catalyzed reactions of PF and pMDI prepolymers. The electronic behavior of phenolic monomers as perturbed by alkali metal hydroxides in an aqueous environment was studied with 1H and 13C NMR. Changes in electronic structure and thus reactivity were related to solvated ionic …
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