• Polymer(Korea)
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• v.32 no.6
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• pp.509-515
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• 2008

The aminated polypropylene melt blown ion exchange fibers were synthesized with acrylic acid monomer onto polypropylene melt blown fibers by radiation-induced polymerization and subsequent amination. Degree of grafting was increased with increasing the acrylic acid monomer concentration and total dose. The highest degree of grafting was obtained 140% at a monomer concentration of 20 v/v% acrylic acid and total dose of 4 kGy. Optimum condition of Mohr's salt was 5.0 $\times10^{-3}$ M. Degree of amination was increased with increasing degree of grafting. Water content was about 1.5 times higher than that of trunk polymer. The maximum ion-exchange capacity was 7.3 meq/g which was 2$\sim$3 times higher than a commercial ion exchange fiber. The average pore size was decreased and BET surface area was increased in order of PPmb, PPmb- g- AAc and APPmb- g- AAc. The average pore size and BET surface area of synthesised fibers were $366.1\;{\AA},\;3.71m^2/g,\;143.3\;{\AA},\;4.94m^2/g,\;40.97\;{\AA},\;8.98m^2/g$, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.367-371
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• 2007

Nanocomposites prepared by PP(Polypropylene) based compatibilizers modified with GMA(Glycidyl methacrylate) and HEMA(Hydroxyethyl methacrylate) were used to investigate the clay dispersion and mechanical properties of them. XRD patterns showed the improvement of dispersion through clay intercalation according to the compatibilizers and comonomer. GMA modified polypropylene gave the best mechanical properties of the nanocomposite with respect to the balance of Flexural modulus (FM) and Notched izod impact strength(IS). Compatibilizers with comonoer commonly have higher grafting yield and lower melt flow rate than those of comonomer free. And they enhanced the clay dispersion and mechanical properties of nanocomposites. Optimum ratio of monomer to comonomer for nanocomposites having better mechanical properties is about 1 to 1 ratio.

• Korean Journal of Optics and Photonics
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• v.3 no.3
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• pp.198-202
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• 1992

Silver ion-exchanged glass waveguide with its large surface index difference and shallow depth is suitable to be used for the hybrid integration of semiconductor device and glass waveguide using the semiconductor film grafting technique. We report characteristics of the planar and channel glass waveguides exchanged in the diluted silver nitrate melt in the visible and infrared spectral region. Especially, we determined the fabrication parameters for single-mode channel waveguide at 1.5.$\mu$m, an important wavelength in the optical communication. Directional couplers with several different configurations were fabricated, and their 3 dB coupling length was determined as a function of wavelenGh and polarization.

• Elastomers and Composites
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• v.58 no.3
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• pp.128-135
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• 2023

To improve the adhesive strength of natural rubber (NR) for a seismic isolation damper, citraconic acid-g-NR (CCA-g-NR) was synthesized via the melt grafting of citraconic acid (CCA) onto NR using an azobisisnomerobutyronitrile (AIBN) initiator. Subsequently, the influence of CCA and AIBN concentrations on the graft ratio G/R (%) and graft efficiency G/E (%) of the CCA-g-NR was investigated. The optimum CCA and AIBN concentrations required to achieve the desired G/R (3.49%) and G/E (49.8%) were found to be 7 phr and 0.13 phr, respectively. Additionally, we studied the influence of CCA-g-NR concentration on the mechanical properties (tensile strength, elongation at break, and modulus at 300%), adhesive strength, and cure characteristics of the rubber compound in the seismic isolation damper. As the concentration of CCA-g-NR increased, the elongation at break and adhesive strength of the compound increased, whereas its tensile strength and modulus at 300% decreased. Moreover, as the concentration increased, the maximum torque decreased and the scorch time was delayed to obtain an optimal vulcanization time.

• Polymer(Korea)
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• v.31 no.1
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• pp.80-85
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• 2007

Maleic anhydride (MA) modified ethylene-propylene-diene terpolymer (MEPDM) was pre-pared from solution polymerization. MEPDM-g-PST copolymer was prepared by melt polymerization of male ate d EPDM and quaternary ammonium silyl polydimethylsiloxane -7,7,8,8- tetracyanoquinodimethane (TCNQ) adduct (PST) in internal mixer and MEPDM-g-PST/HDPE/CB (MPEC) was prepared by com-pounding HDPE, MEPDM-g-PST copolymer and carbon black (CB, 5, 10, 15, and 20 phr), and HDPE/ CB (PEC) by compounding HDPE and CB (5, 10, 15, and 20 phr), respectively. The structure of MEPDM-g-PST copolymer was confirmed by measuring the FTIR. The maximum grafting ratio of MA onto EPDM was 2.35%. The thermal and mechanical properties of the composites were measured and dispersion characteristics of CB in matrix show that CB in MPEC was better dispersed than that in PEC composite.