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Neat Epoxy Resin (neat + epoxy_resin)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Mechanism of interactions of eggshell microparticles with epoxy resins

POLYMER ENGINEERING & SCIENCE, Issue 7 2009
Genzhong Ji
Large surface-area microparticles of natural chicken eggshell were prepared and characterized to illustrate how such particles can improve the toughness of epoxy resins. A small amount of organic compounds, in particular proteins, were found to be present in the microparticles and beneficial to the enhancement of the mechanical properties of the epoxy resins. Scanning electron microscopic analysis of the rough fracture surfaces show that there are full of plastic deformation, voids, cavities, and debonding phenomena in the microparticle-filled composites. Positron annihilation study indicates that the lifetime of ,3 o-Ps varies and the corresponding intensity of I3 becomes weak with the increase of eggshell particle content, which indicates that there is a good interaction between the epoxy resin and the filling particles. This gives rise to significant improvement in the toughness of the filled resin. The impact strength of the epoxy resin composite reaches 16.7 kJ/m2 compared with 9.7 kJ/m2 of neat epoxy resin when the epoxy resin composite is filled with only 5 mass% eggshell particles. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source]

Synthesis and studies of the physical properties of polyaniline and polyurethane-modified epoxy composites

POLYMER ENGINEERING & SCIENCE, Issue 2 2008
Wen-Chin Chiou
Two series of toughened, semiconductive polyaniline (PANI)/polyurethane (PU)-epoxy (PANI/PU-EPOXY) nano-composites were prepared using a conductive polymer, PANI, and PU prepolymer-modified-diglycidyl ether of bisphenol A (DGEBA) epoxy. First, the PU prepolymer-modified epoxy oligomer was synthesized by a stoichiometric reaction between the terminal isocyanate groups of the PU prepolymer and the pendent hydroxyl groups of the epoxide. PU prepolymers were made either of polyester (polybutylene adipate, PBA) or polyether (polypropylene glycol, PPG) segments. The composites were characterized by thermal, morphological, mechanical, and electrical studies. Impact strength was enhanced 100% in PU (PPG 2000)-modified composites; whereas, only ca. 30,50% increases in impact strength were observed for the other modified composites. In addition, the thermal stability of this composite proved superior to that of neat epoxy resin, regardless of a PU content at 27.5 wt%. Scanning electron microscopy (SEM) morphology study showed that the spherical PU (PPG 2000) particles (ca. 0.2,0.5 ,m) dispersed within the matrix accounts for these extraordinary properties. The conductivity of the composite increased to ca. 10,9,10,3 S cm,1 upon addition of PANI when tested in the frequency range 1 kHz,13 MHz. This study demonstrated a useful way to simultaneously improve the toughness and conductivity of the epoxy composite, thus rendering it suitable for electromagnetic interference and various charge dissipation applications. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers [source]

Organic,inorganic hybrid materials derived from epoxy resin and polysiloxanes: Synthesis and characterization

POLYMER ENGINEERING & SCIENCE, Issue 1 2008
C.F. Canto
In this study, hybrid materials based on epoxy resin were prepared as transparent self-supported films by a sol,gel process. 4,4,-Diaminodiphenylmethane or oligomeric epoxy resin were used as precursors, which were conveniently functionalized with trialkoxysilanes as end-groups. The effect of the introduction of poly (dimethylsiloxane) was also investigated. The hybrid films showed good thermal stability, a nondefined glass transition temperature, and a dense morphology without phase segregation. The tendency to a flat surface could be observed by atomic force microscopy. The hybrid films also showed good performance as coatings for glass plates, with an improved hydrophobic character in comparison to neat epoxy resin. POLYM. ENG. SCI., 48:141,148, 2008. © 2007 Society of Plastics Engineers [source]

Effect of Biodegradable Epoxidized Castor Oil on Physicochemical and Mechanical Properties of Epoxy Resins

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 15 2004
Soo-Jin Park
Abstract Summary: Biobased epoxy materials were prepared from diglycidyl ether of bisphenol A (DGEBA) and epoxidized castor oil (ECO) initiated by a latent thermal catalyst. The physicochemical and mechanical interfacial properties of the DGEBA/ECO blends were investigated. As a result, the thermal stability of the cured epoxy blends showed a maximum value in the presence of 10 wt.-% ECO content, which was attributed to the excellent network structure in the DGEBA/ECO blends. The storage modulus and glass transition temperature of the blends were lower than those of neat epoxy resins. The mechanical interfacial properties of the cured specimens were significantly increased with increasing the ECO content. This could be interpreted in terms of the addition of larger soft segments of ECO into the epoxy resins and thus reducing the crosslinking density of the epoxy network, which results in increasing toughness in the blends. KIC values of the DGEBA/ECO blends as a function of ECO content. [source]