No abstract

vi CHAPTER 1. General Introduction 1 CHAPTER 2. Hydrolyzed soy flour and protein isolate in medium density fiberboard applications 28 CHAPTER 3. Effects of degree of protein hydrolysis on soy flour/phenol formaldehyde adhesives 45 CHAPTER 4. Effects of degree of hydrolysis on soy flour and polyamideepichlorohydrin bond strength and stability 60 CHAPTER 5. Urea enhanced soy flour/polyamide-epichlorohydrin Adhesives 77 CHAPTER 6. Summary 96 ACKNOWLEDGEMENTS 99 v LIST OF ABBREVIATIONS AMSP -alkaline modified soy protein isolate ANOVA -analysis of variance ANSI -American National Standards Institute ASTM -American Society for Testing and Methods BWT -boiling water test cps -centipoise DH -degree of hydrolysis DOPA -3,4-dihydroxyphenyl-alanine GH -guanidine hydrochloride GLM -general linear model (SAS statistical analysis model) HS90 -HoneySoy90 (defatted soybean flour from Cenex Harvest States) IB -internal bond strength MDF -medium density fiberboard MDI -methylene diphenyl diisocyanate MMT -million metric tons MOE -modulus of elasticity MOR -modulus of rupture OPA -o-phthaldialdehyde (reagent used in degree of hydrolysis measurement) PAE -polyamide-epichlorohydrin pI -isoelectric point PF -phenol formaldehyde (petroleum based synthetic resin) vi PRF -phenol resorcinol formaldehyde SDBS -sodium dodecyl benzene sulfonate SDS -sodium dodecyl sulfate SPC -soy protein concentrate SF -soy flour SPI -soy protein isolate TMSP -trypsin modified soy protein TS-2B -thickness swell after 2-h boiling test TS-24S -thickness swell after 24-h soaking test UF -urea formaldehyde WSAD -water soaking and drying test vii ABSTRACT Soy protein based adhesives have not been used extensively in wood products since the 1960's because of inferior performance, stability, and water resistance issues relative to petroleum based adhesives. The early soy protein adhesives were made from defatted flours and were dispersed in alkaline solutions to denature proteins and make more polar groups available for adhesion. Recent research has focused on soy flour (SF) and soy protein isolate (SPI) adhesives due to increased phenol prices and concerns over the use and exposure to formaldehyde. In the present work enzyme hydrolysates of SF and SPI were evaluated in phenol formaldehyde (PF) and polyamide-epichlorohydrin (PAE) adhesive formulations. In soy/PF blends the degree of hydrolysis (DH) was an integral factor in both strength and durability. DH >18% was detrimental to the internal bond and thickness swell of medium density fiberboard (MDF) specimens with PF blends. MDF made with blends of hydrolyzed SF/PF with up to 20% soy solids did not significantly differ in strength or durability compared to pure PF resin. Addition of hydrolyzed SF to the adhesive matrix increased the modulus of elasticity of MDF. Similar results were observed when hydrolyzed soy flour was incorporated with PAE. Hydrolysis of SF led to lower viscosity resins, but DH >10% decreased shear strength of plywood specimens. PAE is known commercially for its wet strength attributes, but ...

No abstract

No abstract

Three pyrrololactam alkaloids have been isolated from the marine sponge Phacellia fusca Schmidt collected from the South China Sea, and their structures were determined as 1–3, on the grounds of spectral data. This is the first report of these compounds from this sponge. The structure of 1 was confirmed by X‐ray analysis.