Preparation of Cellulose-Graft Water Retaining Agent: Effect of Reaction Temperature and Initiator

2012 ◽  
Vol 557-559 ◽  
pp. 1022-1025
Author(s):  
Zong Cheng Miao ◽  
Fang Wang ◽  
Deng Deng ◽  
Yong Ming Zhang ◽  
Lei Wang ◽  
...  

Grafting vinyl monomers onto natural cellulose become a preferred method to derive water retaining agent because it afforded unique environmental and commercial advantages. In current work, a series of water retaining agent were prepared by radical solution polymerization of cellulose, partially neutralized acrylic acid and acrylamide using grafted agents as an initiator and N, N-methylenebisacryl- amide as a crosslinker. Fourier transform infrared spectroscopy spectra proved that acrylic acid and acrylamide were grafted onto cellulose backbone and N, N-methylenebisacryl- amide participated in polymerization. The effects of reaction conditions of reaction temperature and initiator amount to water retaining agent were studied using water absorbencies as evaluation standard, the optimum preparation technology was decided.

2012 ◽  
Vol 557-559 ◽  
pp. 1018-1021
Author(s):  
Zong Cheng Miao ◽  
Fang Wang ◽  
Deng Deng ◽  
Yong Ming Zhang ◽  
Lei Wang ◽  
...  

In order to prepare a novel superabsorbent resin based on cellulose, straw pulp cellulose was used as raw material, through etherification preparation of carboxymethyl cellulose, K2S2O8-Na2SO3 oxidationredox system as an initiator, acrylic acid, acrylamide as grafting monomer, crosslinking agent N, N-methylenebisacrylamide were used to synthesize the high water absorbent resin. The effects of reaction conditions to superabsorbent resin were studied using water absorbencies as evaluation standard, the optimum preparation technology was decided.


2011 ◽  
Vol 5 (5-6) ◽  
pp. 223-231 ◽  
Author(s):  
Roque J. Minari ◽  
Gerardo Caceres ◽  
Paola Mandelli ◽  
Mariana M. Yossen ◽  
Manuel Gonzalez-Sierra ◽  
...  

2020 ◽  
Vol 5 (11) ◽  
pp. 2081-2090
Author(s):  
Juri Ilare ◽  
Mattia Sponchioni ◽  
Giuseppe Storti ◽  
Davide Moscatelli

We propose a model for the optimized conversion of semi-continuous poly(acrylic acid) production to continuous preserving the product features.


2020 ◽  
Vol 35 (3) ◽  
pp. 203-215
Author(s):  
Mehmet Emin Diken ◽  
Berna Koçer Kizilduman ◽  
Begümhan Yilmaz Kardaş ◽  
Enes Emre Doğan ◽  
Mehmet Doğan ◽  
...  

The nanocomposite hydrogels were prepared by dispersing of the nanopomegranate seed particles into poly(vinyl alcohol)/poly(acrylic acid) blend matrix in an aqueous medium by the solvent casting method. These hydrogels were characterized using scanning electron microscopy, Fourier transform infrared spectra, differential scanning calorimetry, and optical contact angle instruments. The nanopomegranate seed, blend, and hydrogel nanocomposites were tested for microbial activity. In addition, cytocompatibilities of these blend and hydrogel nanocomposites/composites were tested on human lymphocyte with in vitro MTS cell viability assays. Fourier transform infrared spectra revealed that esterification reaction took place among functional groups in the structure of poly(vinyl alcohol) and poly(acrylic acid). The hydrophilic properties of all hydrogels decreased with increasing nanopomegranate seed content. The mean diameters of the nanopomegranate seed particles were about 88 nm. Nanopomegranate seed particles demonstrated antibacterial properties against gram-positive bacteria, Staphylococcus aureus, and gram-negative bacteria, Escherichia coli. The lymphocyte viabilities increased after addition of nanopomegranate seeds into the polymer blend. The swelling behavior of blend and hydrogels was dependent on the cross-linking density created by the reaction between poly(vinyl alcohol)/poly(acrylic acid) blend and nanopomegranate seed. Scanning electron microscopy images were highly consistent with Fourier transform infrared spectra, differential scanning calorimetry, and antibacterial activity results.


2011 ◽  
Vol 17 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Jiancheng Zhou ◽  
Wu Dongfang ◽  
Birong Zhang ◽  
Yali Guo

A series of single-metal carbonates and Pb-Zn mixed-metal carbonates were prepared as catalysts for alcoholysis of urea with 1,2-propylene glycol (PG) for the synthesis of propylene carbonate (PC). The mixed carbonates all show much better catalytic activities than the single carbonates, arising from a strong synergistic effect between the two crystalline phases, hydrozincite and lead carbonate. The mixed carbonate with Pb/Zn=1:2 gives the highest yield of PC, followed by the mixed carbonate with Pb/Zn=1:3. Furthermore, Taguchi method was used to optimize the synthetic process for improving the yield of PC. It is shown that the reaction temperature is the most significant factor affecting the yield of PC, followed by the reaction time, and that the optimal reaction conditions are the reaction time at 5 hours, the reaction temperature at 180 oC and the catalyst amount at 1.8 wt%, resulting in the highest PC yield of 96.3%.


1995 ◽  
Vol 93 (1) ◽  
pp. 293-300 ◽  
Author(s):  
Neil B. Graham ◽  
Carmel M.G. Hayes

2013 ◽  
Vol 634-638 ◽  
pp. 1968-1976 ◽  
Author(s):  
Shi Han Shen ◽  
Yu Yu Zhang ◽  
Tian Bin Li ◽  
Qing Le Zeng

In this paper, a novel superabsorbent composite material based on acrylic acid (AA), acrylic amide (AM) and inorganic kaolin was synthesized via solution polymerization in aqueous medium with N,N’-methylene bisacrylamide (MBA) as crosslinker and potassium persulfate (KPS) as initiator. The effects of water absorbency of the composite variables, such as neutralization, kaolin concentration and MBA concentration, on the water absorbency were systematically optimized. Evidence of compositing was obtained by a comparison of the Fourier transform infrared spectra of the initial reactants with that of the superabsorbent composites, and its complex structure was confirmed with scanning electron microscope. The water absorbing mechanism was also discussed. The results indicated that the superabsorbent composite material was successfully synthesized and the optimum reaction conditions were as follows: the neutralization degree was 80%, the dosage of kaolin, crosslinker and initiator were 4%, 0.11%, and 0.9% respectively and the mass ratio of AA and AM was 3∶2. The optimum absorbency of the superabsorbent composite material in distilled water could reach 815.6g/g.


2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.


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