• Elastomers and Composites
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• v.50 no.2
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• pp.103-109
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• 2015

In this study, epoxy/anhydride mixing ratio for the highly silica filled compounds with chromium (III) octoate catalyst was investigated at a low curing temperature ($71^{\circ}C$ for 40 hr) by evaluating the compressive strength with the weight ratio ranges from 0.3/1.0 to 1.0/1.0 of epoxy part (Part A)/anhydride part (Part B). In case of epoxy/anhydride compounds used surface unmodified silica by coupling agent, these compounds need excess anhydride unlike the weight ratio in the conventional epoxy/anhydride compounds. In curing behavior, the epoxy/anhydride compounds containing chromium (III) octoate showed high conversions at $71^{\circ}C$ for 40 hr, even if a dipropylene glycol (DPG) was not used as a polymerization initiator. Also, DPG leads to a poor epoxy network structure. In conclusion, the appropriate weight ratio of Part A/Part B of highly silica filled epoxy/anhydride compounds with chromium (III) octoate catalyst is 0.5/1.0 and the maximum amounts of silica is 1470 phr of epoxy resin.

• Elastomers and Composites
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• v.49 no.1
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• pp.59-65
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• 2014

In this study, in order to complete curing reaction of the molding compound comprising an epoxy/anhydride at $71^{\circ}C$ for 40 hours, metal coordination complexes such as cobalt (II) acetylacetonate, potassium acetylacetonate, iron (III) acetylacetonate and chromium (III) octoate as a catalyst were applied to the epoxy/anhydride compounds respectively. The weight ratio of an epoxy part/an anhydride part was adjusted to improve the mechanical properties of the molding compound. According to the experimental results, an epoxy/anhydride compound containing chromium (III) octoate showed a high conversion at $71^{\circ}C$ for 40 hours as well as a proper processability at room temperature among the several metal coordination complexes. For the mechanical properties of the cured epoxy/anhydride compound, the compounds containing weight ratio from 0.9/1 to 0.5/1 of the epoxy part/anhydride part with chromium (III) octoate showed the high flexural strength, and higher compressive strength was shown with increasing of the hardener part.

• Elastomers and Composites
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• v.38 no.3
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• pp.213-226
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• 2003

The cure and rheological behavior of diglycidyl ether of bisphenol F/nadic methyl anhydride resin system with the kinds of imidazole were studied using a differential scanning calorimeter (DSC) and a rotational rheometer. The isothermal traces were employed to analyze cure reaction. The DGEBF/ anhydride conversion profiles showed autocatalyzed reaction characterized by maximum conversion rate at $20{\sim}40 %$ of the reaction. The rate constants ($k_1,\;k_2$) showed temperature dependance, but reaction order did not. The reaction order (m+n) was calculated to be close to 3. There are two reaction mechanisms with the kinds oi catalyst. The gel time was determined by using G'-G" crossover method, and the activation energy was obtained from this results. From measurement of rheological properties it was found that the logarithmic 1:elation time of fused silica filled DBEBF epoxy compounds linearly increased with the content of filler and decreased with temperature. The highly filled epoxy compounds showed typical pseudoplastic behavior, and the viscosity of those decreased with increasing maximum packing ratio.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.2
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• pp.21-27
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• 2000

To develop the underfill materials which are required for the new process of semi-conductor industry, the properties of epoxy/anhydride/cobalt(II) catalyst system with two types of fused silica(1 $\mu\textrm{m}$, 8 $\mu\textrm{m}$) are studied as a function of filler fraction. According to the curing profile, the optimum catalyst amount was 1.0 wt% for full curing at the conditions of $160^{\circ}C$/l5 min., and we could conclude that the viscosity has superior effect on the real flaw through the relationship between surface tension and viscosity data. The underfills which were filled with 1 $\mu\textrm{m}$ fused silica did not show good flowability, but they should be useful by improving the viscosity for a future process which has small gaps. The underfills which were filled with 8 $\mu\textrm{m}$ fused silica showed good flowability when the filler contents were 55~60 vol%. The model which was referred by Matthew can predict the real flow length only when the underfill has high viscosity and low surface tension.

• Macromolecular Research
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• v.17 no.5
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• pp.289-295
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• 2009

Low viscosity aromatic hyperbranched polyester epoxy resin (HTBE) was synthesized by the reaction between epichlorohydrin (ECH) and carboxyl-end hyperbranched polyester (HTB) which was prepared from inexpensive materials $A_2$ (1,4-butanediol glycol, BEG) and $B_3$ (trimellitic anhydride, TMA) by pseudo one-step method. The molar mass of the HTB was calculated from its acid value by "Recursive Probability Approach". The degree of branching (DB) of the HTB was characterized by model compounds and $^1H$ NMR-minus spectrum technology, and the DB of the HTB was about $0.47{\sim}0.63$. The viscosity and epoxy equivalent weight of the HTBE were $3,600{\sim}5,000\;cp$ and lower than 540 g/mol respectively. The reaction mechanism and structure of the $AB_2$ monomer, HTB and HTBE were investigated by MS, $^1H$ NMR and FTIR spectra technology. The molecular size of HTBE is under 8.65 nm and its shape is ellipsoid-like as determined by molecular simulation.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.42-49
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• 2017

To replace phthalate plasticizer for PVC, acetylated monoglyceride (AMG) plasticizers were prepared from plant oil and their plasticization effects were also investigated. Transesterification of coconut oil by glycerol followed by acetylation with acetic anhydride gave AMG-CoCo (Coco : Coconut Oil). In addition, AMG-GMO (GMO : Glycerol monooleate) and AMG-GMO-Epoxy were synthesized by acetylation and epoxidation with glycerol monooleate. It was found that the thermal stability of AMG plasticizers increased in the following order: AMG-GMO-Epoxy > AMG-GMO > AMG-CoCo and all three plasticizers were thermally more stable than those of common petroleum-based plasticizer DOP (Dioctyl phthalate). The tensile strain values of the PVC containing AMG compounds were ca. 770~810%, while tensile strength values were ca. 19~22 MPa, which were higher than those of PVC containing DOP. DMA (Dynamic Mechanical Analysis) results showed that the miscibility of AMG-GMO-Epoxy in PVC was excellent and the $T_g$ of PVC containing AMG-GMO-Epoxy at 50 phr decreased down to $24^{\circ}C$. Finally, the leaching experiment result showed that the weight loss values of PVC containing AMG-GMO and AMG-GMO-Epoxy at 50 phr were as low as 2 and 1%, respectively, indicating that they have high water migration resistance. The above findings suggested that AMG-GMO-Epoxy could be one of plant oil-based PVC plasticizers to replace DOP.