• 방사선산업학회지
• /
• 제8권1호
• /
• pp.49-52
• /
• 2014

Kenaf fibers have excellent properties and possess the potential to be outstanding reinforcing fillers in cement. The grafting of poly(ethylene glycol) methacrylate (PEGMA) to the kenaf fibers is important in improving the compatibility between the fibers and the cement. PEGMA was grafted onto kenaf fibers using gamma-ray radiation. The radiation dose ranged from 20 to 60 kGy, and the dose rate was $10kGy\;h^{-1}$. The degree of grafting increased with increased radiation doses. FT-IR analysis revealed an increase in PEGMA content after gamma-ray radiation induced grafting, further evincing the attachment of PEGMA to the kenaf fibers. The mechanical properties of the gamma-ray grafted kenaf fiber/cement composites were superior to those of the ungrafted kenaf fiber/cement specimens.

• 한국의류학회지
• /
• 제19권6호
• /
• pp.946-954
• /
• 1995

The purpose of this study is to modify the hydrophobic property and dyeability of polyethylene terephthalate fiber. Methacrylic acid (2nA) was graftpolymerized with benzoyl peroxide (BPO) as initiator onto polyethylene terephthalate fabrics. The results were as follow; 1. Graft-polymerization exhibited maximum graft ratio at a temperature of 100"C. 2. The polymer was gradually grafted in great amount to the surface of MA-g-PET as graft ration increase; with the cross-section examination of MA-g-PET, it was discovered that graft-polymeriation had also taken place inside the textile core. 3. Dyes absorption of basic dyes and disperse dyes was improved as craft ratio increase; with resistance to laundering, the former showed grade 3-4 and the latter showed grade 5.de 5.

• 한국염색가공학회지
• /
• 제9권1호
• /
• pp.1-14
• /
• 1997

Nylon 6 grafted with polyacrylamide(PAAm) was synthesized by a dispersion polymerization method at 6$0^{\circ}C$ for 2 hours, and a cresol-soluble graft polymer(CSGP) and water-dispersable graft polymer (WI)GP) were separated. Infra-red(IR) spectrum analysis, differential scanning calorimetery(DSC), thermogravimetery(TG), and X-ray diffraction analysis were carried out to research their structural characteristics.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 가을 학술발표회 논문집
• /
• pp.257-258
• /
• 2003

Crafting process consists of the reversible protection of the hydroxyl groups of the polysaccharide backbone by silylation, followed by the ring-opening polymerization (ROP) of $\varepsilon$-caprolactone (CL) initiated by the free remaining hydroxyl groups of the partially silylated dextran in the presence of tin-based catalysts. The last step relies upon the removal of silylating groups under mild acidic conditions yielding the desired amphiphilic graft copolymers.

• 한국의류산업학회지
• /
• 제6권3호
• /
• pp.384-392
• /
• 2004

The purpose of this study is in development of effective filter-type polymer adsorbent for removal of pollutants from wastewater by UV irradiation graft polymerization. Photografting of acrylic acid (AA) on polypropylene (PP) nonwoven fabric using benzophenone (BP) as a photosensitizer was investigated. Inhibition of homopolymerization was achieved by adding various concentrations of $FeSO_4{\cdot}7H_2O$, $CuSO_4{\cdot}5H_2O$ and Mohr's salt. As AA concentration was increased, the degree of grafting was increased as to a specific value and then decreased, and the effect of BP concentration showed the same tendency. It was also found that the degree of grafting increased with reaction time and reaction temperature. Addition of the polyfunctional monomers and $H_2SO_4$ to the grafting system accelerated the photografting. The melting temperature, molecular weight and breaking stress and breaking strain were decreased with the increase in the degree of grafting.

• Korea-Australia Rheology Journal
• /
• 제17권2호
• /
• pp.41-45
• /
• 2005

As an effort to explore the effective use of carbon nanotubes as a reinforcing material for advanced nano-composites with polymer matrices, multi-walled carbon nanotubes (MWNTs) were successfully incorporated into polystyrene (PS) via in-situ bulk polymerization. Various experimental techniques revealed that the covalent bonds formed between PS radicals and acid-treated carbon nanotubes are favorable resulting in an effective load transfer. The enhanced storage modulus of the nanocomposites suggests a strong possibility for the potential use in industrial applications.

• Macromolecular Research
• /
• 제12권5호
• /
• pp.512-518
• /
• 2004

We have synthesized a novel macromonomer of vinyl-terminated bifunctional polyurethane having a molecular weight of 37,000 g/mol and successfully applied it to the dispersion polymerization of methylmethacrylate(MMA). We verified the presence of the vinyl terminal group and the macromonomer grafted onto the poly(ethylene glycol)(PEG) block in the PMMA particles by using $^1$H and $\^$13/C NMR spectroscopies. Monodisperse PMMA microspheres that have good uniformity of 1.01 were prepared at 20 wt% macromonomer content; we investigated the characteristics of the PMMA particles in terms of their molecular weight, molecular weight distribution, size of the particles, thermal properties, and glass transition temperature. We have found that the synthesized polyurethane macromonomer is an effective stabilizer.

• Macromolecular Research
• /
• 제9권3호
• /
• pp.150-156
• /
• 2001

Polystyrenes(PS) were grafted onto polypropylene(PP) in the PP solution by ultrasonic irradiation-initiated polymerization of styrene. The resulting products consisted of mixtures of homopolymers and PP-PS copolymer because of the homopolymerization of styrene itself and copolymerization with PP. The dependency of the designated polymerization on sonication times was investigated to monitor the evolution lion of the copolymerization. Formation of the PP-PS copolymer was confirmed by FTIR analysis of the reaction products after a proper separation procedure of free PS and PP-PS copolymer. It was found that the tendency for the formation of PP-PS copolymer was closely related with the phase behavior of the PP/styrene mixture which was also influenced by sonication time. In order to verify the effectiveness of the PP-PS copolymer as a compatibilizer for PP/PS blend, melt mixing of PP/PS/PP-PS was performed in a batch mixer. During the mixing, the average torque was higher for the blend containing PP-PS copolymer influencing compatibilization. In accordance with the results from FRIR analysis and torque measurement, the PS domain size remarkably decreased in the PP/PS/PP-PS blend.

• Macromolecular Research
• /
• 제15권2호
• /
• pp.173-177
• /
• 2007

Living anionic and cationic polymerizations have been combined to prepare various types of comb-like copolymers composed of polystyrene (PS) and polyisoprene (PI) blocks, with a precisely controlled architecture. According to the relative placement of these elementary building blocks, combs with randomly distributed PS and PI or with poly(styrene-b-isoprene) diblock branches (I & II, respectively) can be prepared. The reaction procedure initially includes the synthesis of a poly(chloroethylvinyl ether) using living cationic polymerization, which is used as the reactive backbone to successively graft $PS^-Li^+$ and $PI^-Li^+$ or $PI-b-PS^-Li^+$ to obtain structures (I) or (II). The synthesis of Janus-type PS-comb-b-PI-combs (III) initially involves the synthesis of a diblock backbone using living cationic polymerization, which bears two distinct reactive functions having either a protected or activated form. Living $PS^-Li^+$ and $PI^-Li^+$ are then grafted, in two separate steps, onto each of the reactive functions of the backbone, respectively.

• 한국염색가공학회지
• /
• 제1권1호
• /
• pp.7-18
• /
• 1989

The distinguishing characteristic of the glow discharge is that chemical reaction induced by partially ionized gases are limited only to the substrate surface. Most studies have been done on the plasma etching and polymerization. The graft polymerization in vapour phase by cold plasma has been rarely investigated. In this study the system of tub3ar reaction chamber with capacitively coupled electrode of alternative current of 60 Hz was employed for the graft polymerization. The graft polymerization of Acylic Acid(AA) onto the poly (ethylene terephthalate) (PET) was carried out by treatment of PET film and fabric by cold plasma (glow discharge of argon gas), followed by the supply of AA vapour. The graft yield was about 1 wt%. The surface property was determined by contact angle, the surface tension was evaluated by zisman’s plot and equation of surface tension mesurement. The results were as follows: 1. In order to obtain lower contact angle, it was effective to avoid the vicinity of electrodes for a setting position of substrate. 2. Contact angle affected on the monomer pressure and its duration of exposure to the acid vapour. 3. Polymer radical formation was influenced by the changes of the value of current density and plasma treatment time. 4. Total surface tension of plasma grafted PET film increased. With an increase in the carboxylic acid content, the dispersion force decreased, while, the polar force and hydrogen bonding force increased. 5. The contact angle decreased from $75^\circ$ to around $30^\circ$ by plasma grafting. There was no ageing effect on the contact angle after 4 months.