Gel formed during the solid-state graft copolymerization of styrene and spherical polypropylene granules. I. Influence of reaction conditions on the gelation and its mechanism

2007 ◽  
Vol 104 (6) ◽  
pp. 3682-3687 ◽  
Author(s):  
Letian Zhang ◽  
Zhiqiang Fan ◽  
Qingtian Deng ◽  
Zhisheng Fu
Keyword(s):  
Solid State ◽  
Graft Copolymerization ◽  
Reaction Conditions

Synthesis and Spectroscopic Characteristics of Ligands Based on Quinolin-8-Ol as Useful Precursors for Alq3 Type Complexes

2021 ◽  
Vol 903 ◽  
pp. 168-173
Author(s):  
Elmārs Zariņš ◽  
Deins Alksnis ◽  
Patricija Paulsone ◽  
Karlis Balodis ◽  
Aivars Vembris ◽  
...  
Keyword(s):  
Solid State ◽  
Light Emission ◽  
Emission Property ◽  
Blue Luminescence ◽  
Reaction Conditions ◽  
Aggregation Induced Emission ◽  
Chemical Structures ◽  
Emission Enhancement ◽  
Spectroscopic Characteristics ◽  
Reliable Methods

In order to develop reliable methods for the synthesis of various 5-substituted-8-oxyquinoline derivatives for the preparation of Alq3-type complexes, we have improved the reaction conditions on some syntheses described in the literature, successfully synthesized new ligands based on quinolin-8-ol and characterized their chemical structures by NMR. Some of the synthesized quinolin-8-ol derivatives containing incorporated bulky triphenyl or tert-butyl groups showed blue luminescence in the solid state due to the possible aggregation induced emission enhancement (AIEE) with a maximum wavelength around 510 nm. More detailed light-emission property investigation of the mentioned bulky group containing compounds is currently underway.

scholarly journals New Grafted Copolymers Carrying Betaine Units Based on Gellan and N-Vinylimidazole as Precursors for Design of Drug Delivery Systems

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5451
Author(s):  
Stefania Racovita ◽  
Nicolae Baranov ◽  
Ana Maria Macsim ◽  
Catalina Lionte ◽  
Corina Cheptea ◽  
...  
Keyword(s):  
Graft Copolymerization ◽  
Polymer Concentration ◽  
Monomer Concentration ◽  
Ammonium Persulfate ◽  
Nitrogen Atmosphere ◽  
Sustained Drug Release ◽  
Reaction Conditions ◽  
Grafted Polymer ◽  
Grafted Copolymer ◽  
Grafting Reaction

New grafted copolymers possessing structural units of 1-vinyl-3-(1-carboxymethyl) imidazolium betaine were obtained by graft copolymerization of N-vinylimidazole onto gellan gum followed by the polymer-analogous reactions on grafted polymer with the highest grafting percentage using sodium chloroacetate as the betainization agent. The grafted copolymers were prepared using ammonium persulfate/N,N,N′,N′ tetramethylethylenediamine in a nitrogen atmosphere. The grafting reaction conditions were optimized by changing one of the following reaction parameters: initiator concentration, monomer concentration, polymer concentration, reaction time or temperature, while the other parameters remained constant. The highest grafting yield was obtained under the following reaction conditions: ci = 0.08 mol/L, cm = 0.8 mol/L, cp = 8 g/L, tr = 4 h and T = 50 °C. The kinetics of the graft copolymerization of N-vinylimidazole onto gellan was discussed and a suitable reaction mechanism was proposed. The evidence of the grafting reaction was confirmed through FTIR spectroscopy, X-ray diffraction, 1H-NMR spectroscopy and scanning electron microscopy. The grafted copolymer with betaine structure was obtained by a nucleophilic substitution reaction where the betainization agent was sodium chloroacetate. Preliminary results prove the ability of the grafted copolymers to bind amphoteric drugs (cefotaxime) and, therefore, the possibility of developing the new sustained drug release systems.

scholarly journals New Condensation Polymer Precursors Containing Consecutive Silicon Atoms—Decaisopropoxycyclopentasilane and Dodecaethoxyneopentasilane—And Their Sol–Gel Polymerization

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 841
Author(s):  
Sung Jin Park ◽  
Myong Euy Lee ◽  
Hyeon Mo Cho ◽  
Sangdeok Shim
Keyword(s):  
Solid State ◽  
Sol Gel ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Cross Polarization ◽  
Reaction Conditions ◽  
Polymer Precursors ◽  
Sol Gel Process ◽  
Angle Spinning ◽  
Magnetic Resonances

The sol–gel polymerization of alkoxysilanes is a convenient and widely used method for the synthesis of silicon polymers and silicon–organic composites. The development of new sol–gel precursors is very important for obtaining new types of sol–gel products. New condensation polymer precursors containing consecutive silicon atoms—decaisopropoxycyclopentasilane (CPS) and dodecaethoxyneopentasilane (NPS)—were synthesized for the preparation of polysilane–polysiloxane material. The CPS and NPS xerogels were prepared by the sol–gel polymerization of CPS and NPS under three reaction conditions (acidic, basic and neutral). The CPS and NPS xerogels were characterized using N2 physisorption measurements (Brunauer–Emmett–Teller; BET and Brunauer-Joyner-Halenda; BJH), solid-state CP/MAS (cross-polarization/magic angle spinning) NMRs (nuclear magnetic resonances), TEM, and SEM. Their porosity and morphology were strongly affected by the structure of the precursors, and partial oxidative cleavage of Si-Si bonds occurred during the sol–gel process. The new condensation polymer precursors are expected to expand the choice of approaches for new polysilane–polysiloxane.

Modification of Sodium Salt of Partially Carboxymethylated Guar Gum by Graft Copolymerization with Methyl Acrylate

2005 ◽  
Vol 13 (3) ◽  
pp. 301-312
Author(s):  
Jignesh H. Trivedi ◽  
Natu K. Patel ◽  
Harikrishna C. Trivedi ◽  
Kiran Kalia
Keyword(s):  
Sodium Salt ◽  
Methyl Acrylate ◽  
Guar Gum ◽  
Graft Copolymerization ◽  
Kinetic Scheme ◽  
Ceric Ammonium Nitrate ◽  
Electron Microscopic ◽  
Reaction Conditions ◽  
Redox Initiator ◽  
Ir Spectroscopic

Grafting of methyl acrylate onto sodium salt of partially carboxymethylated guar gum (backbone) was carried out using ceric ammonium nitrate as a redox initiator in an aqueous medium. The reaction variables including concentrations of initiator, nitric acid, monomer and amount of the backbone as well as time and temperature were varied for establishing the optimized reaction conditions for grafting. The influence of these reaction parameters on the grafting yields and the rates of polymerization, graft copolymerization and homopolymerization was also studied and the results were discussed. The kinetic scheme of free radical graft copolymerization was proposed and the experimental results were found to agree very well with the proposed kinetic scheme. The graft copolymer sample was characterized by IR-spectroscopic, thermal and scanning electron microscopic techniques.

Study on the Graft Copolymerization of AN onto PP by Using Supercritical Carbon Dioxide

2013 ◽  
Vol 815 ◽  
pp. 717-721 ◽  
Author(s):  
Ya Zhen Wang ◽  
Di Ma ◽  
Cheng E Yue ◽  
Wei Nan Jia ◽  
Yong Li
Keyword(s):  
Carbon Dioxide ◽  
Reaction Time ◽  
Solid State ◽  
Supercritical Carbon Dioxide ◽  
Graft Copolymerization ◽  
Environmentally Benign ◽  
Graft Polymer ◽  
Swelling Agent ◽  
Grafting Reaction ◽  
Supercritical Carbon

The research reported in this paper aimed at exploring the advantages of using supercritical carbon dioxide (scCO2) as an environmentally benign solvent and swelling agent for carrying out the grafting process of acrylonitrile (AN) onto polypropylene (PP) in the solid state by using benzoyl peroxide (BPO) as initiator in the reaction. In order to get a well graft ratio, the effects of various factors in this grafting reaction are investigated. Those factors included the reaction time, reaction temperature, monomer and initiator concentrations and the CO2 pressure. IR was used to characterize the constituent of the graft polymer. Then anti-aging of the PP-g-AN was studied by UV-vis. Results showed that the scCO2-assisted solid-state grafting process of AN onto PP did have some scientifically interesting and industrially relevant advantages over the melt process. Compare with virgin PP, the graft polymer have a better performance in anti-aging.

scholarly journals New Aspects on the Direct Solid State Polycondensation (DSSP) of Aliphatic Nylon Salts: The Case of Hexamethylene Diammonium Dodecanoate

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2625
Author(s):  
Angeliki D. Mytara ◽  
Athanasios D. Porfyris ◽  
Stamatina N. Vouyiouka ◽  
Constantine D. Papaspyrides
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Critical Parameter ◽  
Critical Parameters ◽  
Reaction Conditions ◽  
Solid State Polymerization ◽  
Salt Crystals ◽  
Direct Solid ◽  
End Group ◽  
Aliphatic Polyamide

The direct solid state polymerization (DSSP) of hexamethylene diammonium dodecanoate (PA 612 salt) was investigated for two different salt grades, fossil-based and bio-based. Aliphatic polyamide salts (such as PA 612 salt) are highly susceptible to solid melt transition (SMT) phenomena, which restrain the industrial application of DSSP. To that end, emphasis was given on reactor design, being the critical parameter influencing byproduct diffusion, amine loss and inherent DSSP kinetics. Experiments took place both at the microscale and the laboratory scale, in which two different reactors were tested in terms of bypassing SMT phenomena. The new reactor designed here proved quite successful in maintaining the solid state during the reaction. Scouting experiments were conducted in order to assess the effect of critical parameters and determine appropriate reaction conditions. Fossil-based PA 612 products proved to have a better end-group imbalance in comparison to bio-based ones, which is critical in terms of achieving high molecular weight. Finally, a real DSSP process was demonstrated, starting from PA 612 salt crystals and ending with PA 612 particles.

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