Preparation and Characterization of Hyperbranched Polystyrene Nanocomposite Synthesized by Living Radical Polymerization and Solution Intercalation Method
Mojtaba
Abbasian
author
Asghar
Fathi
author
Ali Akbar
Entezami
author
Mehdi
Jaymand
author
text
article
2013
per
A copolymer of styrene and methyl styrene was synthesized by nitroxide - mediated “living” free radical polymerization )NMP). N-Bromosuccinimide was used as a brominating agent to obtain a copolymer with bromine as its end group. This brominated copolymer was used as macro initiators for atom transfer radical polymerization (ATRP). Chemical modifcation of the clay and transformation of this inorganic material to an organophilic clay was carried out by cation exchange reaction between the clay and hexadecyl trimethyl ammonium chloride salt in deionized water by mechanical stirring. Preparation of nanocomposite was carried out by solution intercalation method. The structures of the terpolymer and other compounds were investigated by 1H NMR, GPC, FTIR, SEM, TEM and XRD methods and their thermal stability was examined by TGA analyses.
Iranian Journal of Polymer Science and Technology
پژوهشگاه پلیمر و پتروشیمی ایران با همکاری انجمن پلیمر ایران
10163255
24
v.
6
no.
2013
433
443
http://jips.ippi.ac.ir/article_607_8b36d24f9041f7504dd9def84fd191bd.pdf
dx.doi.org/10.22063/jipst.2013.607
Mesoporous Silica Formation by Block Copolymers and Cetyltrimethylammonium Bromide as Structure Control Agent
Mohamad Ali
Semsarzadeh
author
Maedeh
Azadeh
author
text
article
2013
per
Block copolymers and cetyltrimethylammonium bromide were used as templates in nano silica structure formation like MCM-41)Mobil Composition of Matter), SBA16 )Santa Barbara Amorphous) and a new compound namely SPB )silicone mesoporous particles, prepared by sol-gel method using PPG-PEG-PPG block copolymer) to compare the porosity and regularity of the products together. In this work tetraethylorthosilicate )TEOS), as silica source and alcohol as surface modifying agent were used because of having the main advantage, compared to an ionic template such as etyltrimethylammonium bromide, in producing larger pores and thicker walls for holding larger catalytic molecules in their pores or increasing their resistance towards fragmentation. In order to study the copolymer as a template, SPB structure was prepared and compared with SBA16 which was found to have broader pore-size distribution and smaller specifc surface area. Using alcohol in particle production resulted in higher formation rate of micelles with improved morphology. Nitrogen adsorption-desorption, X-ray diffraction and electron scanning microscopy confrmed the mesoporous structure and regularity of these synthesized materials. Finally a mechanism is proposed for the formation of these structures.
Iranian Journal of Polymer Science and Technology
پژوهشگاه پلیمر و پتروشیمی ایران با همکاری انجمن پلیمر ایران
10163255
24
v.
6
no.
2013
445
453
http://jips.ippi.ac.ir/article_609_5bef171fca3ba44590ddf752927a6167.pdf
dx.doi.org/10.22063/jipst.2013.609
The Effects of Montmorillonite and Cellulose Nanocrystals on Physical Properties of Carboxymethyl Cellulose/Polyvinyl Alcohol Blend Films
Leila
Abolghasemi Fakhri
author
Babak
Ghanbarzadeh
author
Jalal
Dehghannia
author
Ali Akbar
Entezami
author
text
article
2013
per
Cellulose nanocrystal )CNC) is a type of nanomaterial which is produced by partial hydrolysis of cellulose and elimination of its amorphous regions. CNC has several advantages such as biodegradability and safety toward human health. In this study, CNC was produced from cotton linters and methods such as transmission electron microscopy and atomic force microscopy were used for confrmation of nanoscale size production of cellulose crystals. Carboxymethyl cellulose )CMC)/polyvinyl alcohol )PVA)-nanoclay )MMT) and CMC-PVA-CNC flms, containing 3-10% (wt/wt CMC) nanofllers, were prepared by casting method and their physical properties were compared in order to approve the use of CNC instead of MMT for its contribution in improving the physical properties of carboxymethyl cellulose-based flms. The X-ray diffraction results indicated the formation of an exfoliated nanostructure at all nanoparticle concentrations. The results showed that there was no signifcant difference (p < 0.5) between the moisture absorption properties of flms containing the two types of nanofller. The flms containing nanoclay showed higher mechanical strength compared to those containing CNC. The ultimate tensile strengths of the flms containing 10% nanoclay and CNC were higher than the control flm (69.72% and 47.05%, respectively).
Iranian Journal of Polymer Science and Technology
پژوهشگاه پلیمر و پتروشیمی ایران با همکاری انجمن پلیمر ایران
10163255
24
v.
6
no.
2013
455
466
http://jips.ippi.ac.ir/article_610_21d6aaa014bdc9892f6a14c2e1c1c306.pdf
dx.doi.org/10.22063/jipst.2013.610
Polymer-Modified Bitumen Production Based on Performance Grade for Application in Different Zones of Iran
Mehdi
Shahabi
author
Fereydon
Moghadas Nejad
author
Sholeh
Kazemifard
author
text
article
2013
per
Due to performance grade )PG) zonation of different parts in Iran and poor properties of 60/70 penetration grade bitumens for pavement applications, suitable polymer modifed bitumen was produced. To fulfll this purpose, different PMBs samples were produced using 60/70 penetration grade bitumen and various percentages of VB (20 and 25%), with different percentages of SBS Calprene C501 ( 4, 4.5, 5 and 5.5%), in a high shear homogenizer in 1 h mixing time at 160°C temperature. To determine the performance grade, aging effect, low temperature performance and rheological properties such as evaluation of rutting and fatigue factors some SHRPs measurements )DSR, RV, RTFOT, PAV and BBR) were conducted. The results showed that the sample with 5.5% SBS with 20 and 25% VB, at high temperatures presented good properties such as: the best performance grade )76°C), the highest resistance and elastic behavior in comparison with the other samples. These samples were subjected to rutting and fatigue tests for both aged bitumen in RTFOT and unaged bitumen. The results indicated that adding SBS to bitumen could not improve the performance at low temperatures, compared to 60/70 grade bitumen, but it did improve the properties of polymer-modifed bitumen at similar low temperature (-18°C). So, samples with 4, 4.5 and 5% SBS with 20 and 25% VB, are suitable to be applied in provinces which 60/70 grade bitumens are not suitable. In some provinces such as Khoozestan, with a PG of 76, the compositions with 5.5% SBS with 20 and 25% VB, are found to be suitable.
Iranian Journal of Polymer Science and Technology
پژوهشگاه پلیمر و پتروشیمی ایران با همکاری انجمن پلیمر ایران
10163255
24
v.
6
no.
2013
467
479
http://jips.ippi.ac.ir/article_611_c2225dc86451886c69fae991162d0cd5.pdf
dx.doi.org/10.22063/jipst.2013.611
Mechanical Properties, Shrinkage Behavior and Water Absorption of PA6/PP/CaCO3 Nanocomposites
Karim
Shelesh-Nezhad
author
Saeed
Montakhabi-Kalajahi
author
Javad
Ehsani-zonuz
author
text
article
2013
per
Nanocomposites based on polyamide 6/polypropylene )PA6/PP 67/33) blend containing 2.5 to 10 phr of nano-CaCO3 and 5 phr of maleated polypropylene )PP-g-MAH) as compatibilizer were prepared by melt compounding followed by injection molding. The mechanical properties, water absorption, as well as shrinkage behavior were characterized and the morphology was studied using scanning electron microscopy. The presence of PP, PP-g-MAH and nano-CaCO3 lowered the amount of water absorption as high as 72 wt%. Morphology analysis indicated that the addition of PP-g-MAH can signifcantly improve the adhesion between PA6 and PP phases. The incorporation of PP-g-MAH led to 24% increase in fexural and impact strength, 27% rise in tensile strength and approximately 100% increase in elongation-at-break. The addition of nano-CaCO3 particles increased the impact resistance and fexural strength. The results of experiments indicated that the maximum fexural strength was achieved by adding 5 phr of nano-CaCO3 which was 16% greater than pure PA6, and the maximum impact strength was attained by adding 7.5 phr of nano-CaCO3 which was 29% superior compared to pure PA6. The incorporation of 10 phr of nano-CaCO3 particles led to fller agglomeration and, consequently, the impact strength was dramatically dropped. Dimensional characterization of molded samples revealed that the incorporation of PP-g-MAH can raise the shrinkage, but the addition of nano-CaCO3 has not had any considerable effect on the shrinkage of nanocomposites.
Iranian Journal of Polymer Science and Technology
پژوهشگاه پلیمر و پتروشیمی ایران با همکاری انجمن پلیمر ایران
10163255
24
v.
6
no.
2013
481
492
http://jips.ippi.ac.ir/article_612_c983e2379c7d6b9f20d76d6612db465e.pdf
dx.doi.org/10.22063/jipst.2013.612
Functionality Effect of Acrylic Pressure Sensitive Adhesive Formulations on Release Performance and Adhesion Properties of Stimulants in
an Adhesive Patch
S. Mojtaba
Taghizadeh
author
Ali Reza
Joorabloo
author
text
article
2013
per
Drug-in-adhesive transdermal drug delivery systems )TDDSs) containing stimulants, termed as energetic substances, such as caffeine and pantothenic acid, were studied. Caffeine is a white crystalline substance and a stimulant to central nervous system. In humans, caffeine acts as a central nervous system stimulant, temporarily warding off drowsiness and restoring alertness. Pantothenic acid, also recognized as vitamin B5, is a water-soluble vitamin. For many animals, pantothenic acid is an essential nutrient. Animals require pantothenic acid to synthesize and metabolize proteins, carbohydrates and fats. For this purpose caffeine and pantothenic acid were used as drug components with 6.32% and 1.12% loadings, in different functional and non-functional acrylic pressure sensitive adhesives (PSAs) of 52.89%, respectively. Ethylene glycol as a chemical enhancer was used in all TDDSs with 39.67%. The effect of PSAs type on in vitro release and adhesion properties (peel strength and tack values) from drug delivery devices were evaluated. It was found that TDDS containing -COOH functional PSA showed the lowest steady state fux. The adhesion properties of the samples were improved by addition of functional acrylic PSA in formulations.
Iranian Journal of Polymer Science and Technology
پژوهشگاه پلیمر و پتروشیمی ایران با همکاری انجمن پلیمر ایران
10163255
24
v.
6
no.
2013
493
503
http://jips.ippi.ac.ir/article_613_51a2bf25f6aed34c6ddeb2f3e0be2b6d.pdf
dx.doi.org/10.22063/jipst.2013.613
Synthesis of Hydrogel Nanocomposites of Acrylamide-Itaconic Acid Using Laponite and Study of Crystal Violet Dye Adsorption
Gholam
Bagheri Marandi
author
Maryam
Baharloui
author
text
article
2013
per
The clay crosslinked hydrogel nanocomposites were synthesized by graft copolymerization of acrylamide and itaconic acid in the presence of different amounts of laponite using ammonium persulfate and N,N,N\',N\'-tetramethylethylene diamine )TEMED) as a free radical initiator and catalyst, respectively. The XRD patterns of nanocomposites showed that the clay layers are completely exfoliated and uniformly dispersed in polymeric matrix. The effect of laponite content on the equilibrium swelling and cationic dye uptake of crystal violet was investigated. It is observed that with increasing clay content in hydrogel composition, the water absorbency is increased. In the dye absorption studies, it was found that amount of dye uptake and removal effciency increased with increasing laponite content. Also, the synthesized samples adsorb higher amount of crystal violet in higher concentrations of dye. Therefore, these nanocomposites could be used for removal of crystal violet dye from wastewater.
Iranian Journal of Polymer Science and Technology
پژوهشگاه پلیمر و پتروشیمی ایران با همکاری انجمن پلیمر ایران
10163255
24
v.
6
no.
2013
505
514
http://jips.ippi.ac.ir/article_614_d69e98c995bbba4cacc999975feb2611.pdf
dx.doi.org/10.22063/jipst.2013.614