Papers by Keyword: Interpenetrating Network

Abstract: Hydrogel is one of the most interesting materials for use as wound dressing. In this study, interpenetrating network (IPN) hydrogels were synthesized by free radical copolymerization of sodium salt of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and N-vinylpyrrolidone (NVP), in the presence of poly (vinyl alcohol) (PVOH). The incorporation of PVOH offered the hydrophilicity to the hydrogel. The polymerization was carried out using N,N-methylene-bis-acrylamide and 4,4-azo-bis (4-cyanopentanoic acid) as a crosslinker and UV-photoinitiator, respectively. The successful of polymerization was indicated by gel content which was in the range of 86 90%. The structure of prepared hydrogels was confirmed by Fourier Transform Infrared Spectroscopy. In addition, the hydrogel-water interaction was investigated by mean of water content and water retention. Manipulation of the AMPS/NVP ratio significantly altered the properties of the hydrogels. As expected, the interaction of hydrogel and water decreased as increasing of NVP contents due to this monomer provides more hydrophobic functional groups. In conclusion, it is believed that the prepared AMPS/NVP/PVOH interpenetrating network hydrogels show the potential for use as temporary wound dressing.

Abstract: Normal 0 false false false EN-US X-NONE TH Interpenetrating network (IPN) hydrogel was a hydrogel fabrication from crosslinked polymers that was developed to enhance the mechanical and physical properties of conventional hydrogel. In this study, IPN hydrogel was fabricated by blending crosslinked natural rubber and crosslinked modified rice starch at room temperature with rubber to starch component ratio of 1:2. Crosslinked natural rubber was prepared via free radical polymerization of natural rubber latex with N,N′-methylenebisacrylamide (MBA) as a crosslinker. Crosslinked starch component was also prepared from pregelatinized starch with maleic acid by heat. The effects of MBA amount and different types of modified starch [glutinous rice starch (mGst) and rice starch (mRst)] on hydrogel properties such as water absorptions, swelling properties, physical morphology and crosslink density were investigated. The results showed that IPN hydrogel containing mRst provided higher water absorption and swelling property than mGst due to its amylose content. In addition, crosslinker amount in rubber component positively related to water absorption and swelling property. The results illustrated that IPN hydrogel with 2 phr MBA provided a greater water absorption and swelling property than IPN hydrogel with 1 phr MBA due to the interior porous structure within polymer matrix. Conclusively, IPN hydrogel comprising of NRL and modified starch was applicable to use as a pharmaceutical material in further study. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; mso-bidi-font-size:14.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Cordia New"; mso-bidi-theme-font:minor-bidi;}

Abstract: A novel thermoresponsive Cu(II) ion-imprinted hydrogel [Cu(II)-IIH] with interpenetrating network structure has been prepared to remove Cu(II) ions with high selectivity. The Cu(II)-IIH was prepared by free radical/cationic hybrid photopolymerization of N-isopropylacrylamide (NIPAM) and triethylene glycol divinyl ether (DVE-3) using Cu(II) ion as template. The Cu(II)-IIH was used to remove heavy metal ions from aqueous solution at 20 and 40oC. The Cu(II)-IIH selectively bound the template ion above a lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) (PNIPAM). The memory was fixed by shrinking above the LCST, and was deleted by swelling below the LCST. Selective adsorption study indicated that ion imprinting resulted in stronger affinity of the Cu(II)-IIH toward Cu(II) ions than other competitor metal ions compared with the non-imprinted hydrogel (NIH).

Abstract: An interpenetrating polymer network was formed by blending of PLLA and PEG cross-linked β-CD to improve the toughness of PLLA, and the mechanical properties of PLLA composites were studied using tensile test. The PLLA composite samples exhibited a single glass transition and their T_g values decreased with increasing PEG/β-CD content, indicating that PLLA and PEG/β-CD are miscible. The PLLA composite samples aged at room temperature achieved the highest fracture strain (about 235%), about 40 times that of the original PLLA sample, while the Young's modulus was not seriously hampered.