Polymerization of 2-(substituted methyl)acrylate bearing ω-methoxyoligoethyleneoxy groups as side chains to new low Tg polymer

1993 ◽  
Vol 31 (13) ◽  
pp. 3433-3438 ◽  
Author(s):  
Bunichiro Yamada ◽  
Seiya Kobatake ◽  
Shuzo Aoki
Keyword(s):  
Methyl Acrylate ◽  
Side Chains

Spinning of Fibers from Graft Copolymers of Polyacrylonitrile and Poly(Methyl Acrylate)

1976 ◽  
Vol 46 (2) ◽  
pp. 77-81 ◽  
Author(s):  
Samy Abdel Monem El-Garf
Keyword(s):  
Graft Copolymer ◽  
Methyl Acrylate ◽  
Graft Copolymers ◽  
Coagulation Bath ◽  
Side Chains ◽  
Initial Value

Fibers were spun from graft copolymers of polyacrylonitrile and poly(methyl acrylate). Increasing poly(methyl acrylate) side chains from 5 to 8% decreased the viscosity of the spinning solution in dimethylformamide. The spinning solutions were unstable. When the graft copolymer contained 5% side chains, the viscosity of these solutions returned to almost its initial value by heating. Fibers were obtained from graft copolymers containing from 5–13% poly(methyl acrylate) side chains. These were formed at the temperature of the coagulation bath (50°C), while at temperatures less than 50°C the fibers were not obtained. Weak fibers were produced from a graft copolymer containing 13% side chains at the temperatures of the coagulation bath (20 and 50°C). No fibers were obtained from graft copolymer containing 25% side chains. The method of dissolution of the graft copolymers does affect the drawing of fibers produced from them. It was observed that the heating of the spinning solution decreases the amount of drawing of the produced fibers. The presence of the flexible side chains of poly(methyl acrylate) in the graft copolymer improves the maximum possible degree of drawing of the fibers relative to that of fibers from the initial linear copolymer and homopolyacrylonitrile.

The Effect of a Method of Dissolution of Graft Copolymer of Polyacrylonitrile and Poly(Methyl Acrylate) on Drawability and Properties of Spun Fibers

1976 ◽  
Vol 46 (10) ◽  
pp. 767-770
Author(s):  
Samy Abdel Monem El-Garf
Keyword(s):  
Graft Copolymer ◽  
Methyl Acrylate ◽  
Modulus Of Elasticity ◽  
Abrasion Resistance ◽  
Side Chains ◽  
Yarn Strength ◽  
Dissolution Temperature ◽  
Initial Modulus ◽  
Spun Fibers

It was found that dissolution of the graft copolymer has an effect on drawability and other properties of fibers spun from this graft copolymer. The resistance to double bending and abrasion resistance are considerably decreased with the increase of the dissolution temperature. The breaking properties were not greatly changed. The maximum loop and knotted yarn strength was reached when the polymer was dissolved by heating. These values are 100% and 99% of the original, respectively—higher than those obtained from PAN and PANM. The presence of 5% PMA in the side chains of the graft copolymer increased the flexibility of these chains. This is evident from the decrease of the initial modulus of elasticity from the values obtained for PANM and PAN.

Synthesis of partially biobased polymer-bearing reactive epoxy groups in the side chains by radical copolymerization of limonene oxide with methyl acrylate

2012 ◽  
Vol 70 (4) ◽  
pp. 1113-1123 ◽  
Author(s):  
Hisatoyo Morinaga ◽  
Yoshihide Kiyokawa ◽  
Mei Kataoka ◽  
Junya Masuda ◽  
Daisuke Nagai
Keyword(s):  
Methyl Acrylate ◽  
Radical Copolymerization ◽  
Side Chains ◽  
Limonene Oxide ◽  
Polymer Bearing ◽  
Epoxy Groups

Anhydrous proton-conducting electrolyte based on a nematic poly(methyl acrylate) containing sulfonated side chains

2014 ◽  
Vol 131 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
Ting Liang ◽  
Yong Wu ◽  
Shuai Tan ◽  
Caihong Wang
Keyword(s):  
Methyl Acrylate ◽  
Side Chains ◽  
Proton Conducting

Biomedical Materials to Repair Retinal Detachments

1985 ◽  
Vol 55 ◽  
Author(s):  
Miguel F. Refojo
Keyword(s):  
Retinal Detachment ◽  
Silicone Rubber ◽  
Methyl Acrylate ◽  
Silicone Oil ◽  
Vitreous Body ◽  
Light Sensitivity ◽  
Scleral Buckling ◽  
Intraocular Injection ◽  
Other Substances

ABSTRACTImplants are essential for the repair of retinal detachments. The implant buckles the wall of the eye and apposes the detached retina with the choroid, thus restoring light sensitivity to the retina. The scleral buckling also relieves traction on the retina from a shrinking vitreous body. The implant materials most commonly used are solid silicone rubber and silicone sponges, but both types have some disadvantages. A poly(hydroxyethyl acrylate-co-methyl acrylate) hydrogel implant with improved properties of softness and antibiotic absorption is also available for retinal detachment surgery. Proliferative vitreoretinopathy involves various conditions of retinal detachment complicated by vitreous fibrosis, which, after vitrectomy, may be treated with intraocular injection of fluids that support the retina against the choroid. For conditions requiring a long-term implant, silicone oil although controversial is the material of choice. Many other substances have been investigated but none better has yet been found.

Influence of Flexible Side-Chains on the Breathing Phase Transition of Pillared Layer MOFs: A Force Field Investigation

2020 ◽  
Author(s):  
Julian Keupp ◽  
Johannes P. Dürholt ◽  
Rochus Schmid
Keyword(s):  
First Principles ◽  
Good Accuracy ◽  
Field Investigation ◽  
Square Lattice ◽  
Side Chain ◽  
Second Step ◽  
Side Chains ◽  
Dynamics Simulations ◽  
Complex Phenomena ◽  
Closed Pore

The prototypical pillared layer MOFs, formed by a square lattice of paddle-<br>wheel units and connected by dinitrogen pillars, can undergo a breathing phase<br>transition by a “wine-rack” type motion of the square lattice. We studied this not<br>yet fully understood behavior using an accurate first principles parameterized force<br>field (MOF-FF) for larger nanocrystallites on the example of Zn 2 (bdc) 2 (dabco) [bdc:<br>benzenedicarboxylate, dabco: (1,4-diazabicyclo[2.2.2]octane)] and found clear indi-<br>cations for an interface between a closed and an open pore phase traveling through<br>the system during the phase transformation [Adv. Theory Simul. 2019, 2, 11]. In<br>conventional simulations in small supercells this mechanism is prevented by periodic<br>boundary conditions (PBC), enforcing a synchronous transformation of the entire<br>crystal. Here, we extend this investigation to pillared layer MOFs with flexible<br>side-chains, attached to the linker. Such functionalized (fu-)MOFs are experimen-<br>tally known to have different properties with the side-chains acting as fixed guest<br>molecules. First, in order to extend the parameterization for such flexible groups,<br>1a new parametrization strategy for MOF-FF had to be developed, using a multi-<br>structure force based fit method. The resulting parametrization for a library of<br>fu-MOFs is then validated with respect to a set of reference systems and shows very<br>good accuracy. In the second step, a series of fu-MOFs with increasing side-chain<br>length is studied with respect to the influence of the side-chains on the breathing<br>behavior. For small supercells in PBC a systematic trend of the closed pore volume<br>with the chain length is observed. However, for a nanocrystallite model a distinct<br>interface between a closed and an open pore phase is visible only for the short chain<br>length, whereas for longer chains the interface broadens and a nearly concerted trans-<br>formation is observed. Only by molecular dynamics simulations using accurate force<br>fields such complex phenomena can be studied on a molecular level.

Pathway Complexity in the Stacking of Imine-linked Macrocycles Related to Two-Dimensional Covalent Organic Frameworks

2019 ◽  
Author(s):  
Shiwei Wang ◽  
Anton Chavez ◽  
Simil Thomas ◽  
Hong Li ◽  
Nathan C. Flanders ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Structural Similarity ◽  
Discrete Models ◽  
Side Chains ◽  
Two Dimensional ◽  
Assembly Process ◽  
Covalent Organic Frameworks ◽  
Electron Systems ◽  
Monomer Structure ◽  
Kinetic Traps

This work reports on the assembly of imine-linked macrocycles that serve as models of two-dimensional covalent organic frameworks (2D COFs). Interlayer interactions play an important role in the formation of 2D COFs, yet the effect of monomer structure on COF formation, crystallinity, and susceptibility to exfoliation are not well understood. For example, monomers with both electron-rich and electron-poor π-electron systems have been proposed to strengthen interlayer inter-actions and improve crystallinity. Here we probe these effects by studying the stacking behavior of imine-linked macrocycles that represent discrete models of 2D COFs. <div><br></div><div>Specifically, macrocycles based on terephthaldehyde (PDA) or 2,5-dimethoxyterephthaldehyde (DMPDA) stack upon cooling molecularly dissolved solutions. Both macrocycles assemble cooperatively with similar ΔHe values of -97 kJ/mol and -101 kJ/mol, respectively, although the DMPDA macrocycle assembly process showed a more straightforward temperature dependence. Circular dichroism spectroscopy performed on macrocycles bearing chiral side chains revealed a helix reversion process for the PDA macrocycles that was not observed for the DMPDA macrocycles. <br></div><div><br></div><div>Given the structural similarity of these monomers, these findings demonstrate that the stacking processes associated with nanotubes derived from these macrocycles, as well as for the corresponding COFs, are complex and susceptible to kinetic traps, casting doubt on the relevance of thermodynamic arguments for improving materials quality. <br></div>

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