scholarly journals Thermolysis of RAFT-Synthesized Poly(Methyl Methacrylate)

2006 ◽  
Vol 59 (10) ◽  
pp. 755 ◽  
Author(s):  
Bill Chong ◽  
Graeme Moad ◽  
Ezio Rizzardo ◽  
Melissa Skidmore ◽  
San H. Thang
Keyword(s):  
Weight Loss ◽  
Methyl Methacrylate ◽  
1H Nmr Spectroscopy ◽  
Gel Permeation Chromatography ◽  
Dominant Mechanism ◽  
Elimination Process ◽  
Poly Methyl Methacrylate ◽  
Gel Permeation ◽  
Raft Agent ◽  
End Group

Thermolysis provides a simple and efficient way of eliminating thiocarbonylthio groups from RAFT-synthesized polymers. The course of thermolysis of poly(methyl methacrylate) (PMMA) prepared with dithiobenzoate and trithiocarbonate RAFT agents was followed by thermogravimetric analysis (TGA), 1H NMR spectroscopy, and gel permeation chromatography (GPC). The weight loss profile observed depends strongly on the RAFT agent used during polymer synthesis. PMMA with a methyl trithiocarbonate end group undergoes loss of that end group at ~180°C, at least in part, by a mechanism believed to involve homolysis of the C–CS2SCH3 bond and subsequent depropagation. In contrast, PMMA with a dithiobenzoate end appears more stable. Only the end group is lost at ~180°C and the dominant mechanism is proposed to be a concerted elimination process analogous to that involved in the Chugaev reaction.

Modification of Hydroxyapatite with Polymer Brushes

2012 ◽  
Vol 714 ◽  
pp. 291-295 ◽  
Author(s):  
Błażej Włodarczyk ◽  
Joanna Pietrasik ◽  
Marian Zaborski
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Polymer Brushes ◽  
Good Control ◽  
Gel Permeation Chromatography ◽  
Isobutyric Acid ◽  
Cross Linking ◽  
Poly Methyl Methacrylate ◽  
Gel Permeation ◽  
Copolymer Brushes

The synthesis of polymer brushes containing poly (methyl methacrylate) (PMMA) chains grafted from hydroxyapatite (HAP) particles was disscussed. Surface of commercially available hydroxyapatite was first modified with atom transfer radical polymerization (ATRP) initiator and hydrophobized with isobutyric acid, and then surface-initiated ATRP was conducted. Properties of obtained hybrids were studied by dynamic light scattering (DLS) and gel permeation chromatography (GPC). Polymers with various molecular weight up toMn=96,100 g/mol were obtained with good control;Mw/Mn<1.2. Copolymer brushes of poly (methyl methacrylate-stat-benzophenone methacrylate) (P(MMA-stat-BPMA) were also synthesized and cross-linking ability of such materials under UV radiation was confirmed.

The Synthesis of Binuclear Mono-Cyclopentadinyl Titanocene and its Using for Aqueous Homo-Polymerization of Methyl Methacrylate

2010 ◽  
Vol 44-47 ◽  
pp. 3036-3040
Author(s):  
Yu Jing Nie ◽  
Zheng Zai Cheng ◽  
Rui Lei ◽  
Xiao Chao Yan ◽  
Su Su Lin
Keyword(s):  
Nmr Spectroscopy ◽  
Methyl Methacrylate ◽  
1H Nmr Spectroscopy ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Reaction Parameters ◽  
Titanium Complex ◽  
Gel Permeation ◽  
Temperature Time ◽  
Water Amount

One binuclear mono-cyclopentadinyl titanocene, CpTiCl3(CH2)4CpTiCl3, has been synthesized by a new ways and characterized by 1H-NMR spectroscopy and elemental analysis. Its aqueous medium polymerization properties of methyl methacrylate (MMA) have been pursued with an anionic surfactant, sodiumn dodecylsulfate(SDS) in water. The obtained polymers were characterized by gel permeation chromatography(GPC). GPC results showed that the dinuclear titanium complex might provide PMMA with broad PDI(PDI=10.82). Influences of reaction parameters, such as temperature, time, MMA/Cat(molar ratio) and water amount were studied in detail. Under the conditions of the temperature was 55 °C, the reaction lasted l5h, the molar ratio of Cat to MMA was l:200, and the volume of water consumed was 40 ml, the conversion of MMA was as high as 70%.

Synthesis of poly(methyl methacrylate)-b-poly(acrylic acid) by DPE method

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Dong Chen ◽  
Ruixue Liu ◽  
Zhifeng Fu ◽  
Yan Shi
Keyword(s):  
Molecular Weight ◽  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
Diblock Copolymer ◽  
Self Assembly ◽  
Gel Permeation Chromatography ◽  
Amphiphilic Diblock Copolymer ◽  
Poly Methyl Methacrylate ◽  
Copolymer Poly ◽  
Poly Acrylic Acid

AbstractAmphiphilic diblock copolymer poly(methyl methacrylate)-b-poly(acrylic acid) (PMMA-b-PAA) was prepared by 1,1-diphenylethene (DPE) method. Firstly, free radical polymerization of methyl methacrylate was carried out with AIBN as initiator in the presence of DPE, giving a DPE-containing PMMA precursor with controlled molecular weight. tert-Butyl acrylate (tBA) was then polymerized in the presence of the PMMA precursor, and PMMA-b-PtBA diblock copolymer with controlled molecular weight was prepared. Finally, amphiphilic diblock copolymer PMMA-b-PAA was obtained by hydrolysis of PMMA-b-PtBA. The formation of PMMA-b-PAA was confirmed by 1H NMR spectrum and gel permeation chromatography. Transmission electron microscopy and dynamic light scattering were used to detect the self-assembly behavior of the amphiphilic diblock polymers in methanol.

scholarly journals Synthesis of Poly(methyl methacrylate)-b-poly(N-isopropylacrylamide) Block Copolymer by Redox Polymerization and Atom Transfer Radical Polymerization

2018 ◽  
Vol 18 (3) ◽  
pp. 537 ◽  
Author(s):  
Melahat Göktaş ◽  
Guodong Deng
Keyword(s):  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Gel Permeation Chromatography ◽  
High Yield ◽  
Resonance Spectroscopy ◽  
Atom Transfer ◽  
Poly Methyl Methacrylate ◽  
Redox Polymerization

Poly(methyl methacrylate)-b-poly(N-isopropylacrylamide) [PMMA-b-PNIPAM] block copolymers were obtained by a combination of redox polymerization and atom transfer radical polymerization (ATRP) methods in two steps. For this purpose, PMMA macroinitator (ATRP-macroinitiator) was synthesized by redox polymerization of methyl methacrylate and 3-bromo-1-propanol using Ce(NH4)2(NO3)6 as a catalyst. The synthesis of PMMA-b-PNIPAM block copolymers was carried out by means of ATRP of ATRP-macroinitiator and NIPAM at 60 °C. The block copolymers were obtained in high yield and high molecular weight. The characterization of products was accomplished by using multi instruments and methods such as nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis.

Synthesis and thermal decomposition kinetics of poly(methyl methacrylate)-b-poly(styrene) block copolymers

2015 ◽  
Vol 30 (5) ◽  
pp. 691-706 ◽  
Author(s):  
Xinghua Guan ◽  
Xiaoyan Ma ◽  
Hualong Zhou ◽  
Fang Chen ◽  
Zhiguang Li
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Weight Loss ◽  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Terminal Group ◽  
Loss Ratio ◽  
Poly Methyl Methacrylate ◽  
Second Stage ◽  
Weight Loss Ratio

Two diblock copolymers of poly(methyl methacrylate)- block-poly(styrene) with chlorine as terminal group (PMMA- b-PS-Cl) were synthesized via two-step atom transfer radical polymerization. The structures of the block copolymers were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and gel permeation chromatography. Thermal properties including glass transition temperature ( Tg) and thermal stability were studied by differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. The block copolymers of PMMA- b-PS-Cl exhibited two glass transitions, which were attributed to the Tgs of PMMA and PS segments, respectively. According to TGA, thermal decompositions of PMMA macro-initiator and PMMA- b-PS-Cl block copolymers had two stages. The weight loss ratio in the second stage was more significant than that in the first stage, which may be attributed to the separation of the halogen atom from the terminal group and the formation of a double bond. The breaking down of the backbone dominates in the second stage in which the weight loss ratio was more than 70%, represented the main stage of pyrolysis. It was found that the introduction of the PS chain remarkably enhanced the thermal stability of the copolymer, thus endowing the block copolymers high activation energy for thermal decomposition. On the other hand, the remaining two pyrolysis procedures further indicated that thermodynamic mechanism didn’t change due to the introduction of PS segments.

Polymerization of Methyl Methacrylate with a Novel Titanium Complex

2011 ◽  
Vol 179-180 ◽  
pp. 1203-1207
Author(s):  
Zheng Zai Cheng ◽  
Yu Jing Nie ◽  
Xiao Chao Yan ◽  
Rui Lei ◽  
Su Su Lin
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Ligand Complex ◽  
Dichloromethane Solution ◽  
Titanium Complex ◽  
Methyl Methacrylate Polymerization ◽  
Gel Permeation ◽  
Very High

Novel titanium complex [2-O-(5- NO2)C6H3CH=N[(C6H4) –2-O ]]2TiCl2 (1) has been prepared by treatment of the ligand complex 1a with TiCl4•2THF in dichloromethane solution. The complex 1a and 1 were characterized by 1H-NMR . Activated by MAO, Complex 1 displayed very high activity for methyl methacrylate polymerization and the viscosity-average molecular weight of PMMA is more than 35×104 at 60°C.The molecular-weight distribution of PMMA measured by gel permeation chromatography (GPC) is narrow.

Sign in / Sign up

Export Citation Format

Share Document