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Self-organizing cyclolinear organosilicon polymers in bulk and on the surface of water.

Makarova NN, Astapova TV, Buzin AI, Polishchuk AP, Chizhova NV, Petrova IM - Int J Mol Sci (2013)

Bottom Line: It was shown that on introduction of CH2 groups into the methylcyclohexasiloxane unit, the polymer retains the ability to self-organize with formation of a mesomorphic state in a wide temperature range, while on introduction of (CH2)2 fragments in a cyclotetrasiloxane unit or in a bridge connecting two methylcyclotetra(hexa)siloxane units it does not.It was revealed that all polymers form monomolecular films at the air/water interface, excluding those having longer hydrophobic fragment than hydrophilic ones.The ability to form multilayers depends on the surroundings of Si atom in the bridge between the cycles.

View Article: PubMed Central - PubMed

Affiliation: Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova str., Moscow 119991, Russian Federation. buzin@cc.nifhi.ac.ru.

ABSTRACT
Cyclolinear organocarbosiloxane polymers with varying content and location of (CH2)n groups in the monomer unit were synthesized by reactions of heterofunctional polycondensation and polyaddition of difunctional organocyclosiloxanes and organocyclocarbosiloxanes. Their bulk properties were studied by differential scanning calorimetry and X-ray structural analysis. It was shown that on introduction of CH2 groups into the methylcyclohexasiloxane unit, the polymer retains the ability to self-organize with formation of a mesomorphic state in a wide temperature range, while on introduction of (CH2)2 fragments in a cyclotetrasiloxane unit or in a bridge connecting two methylcyclotetra(hexa)siloxane units it does not. Comparison of the X-ray data of dihydroxy derivatives of decamethylcyclohexasiloxane and decamethyl-5-carbocyclohexasiloxane with packing of cyclolinear organosilicon polymers in bulk shows that the polymer inherits the layered type of crystalline structure typical for monomers. Langmuir films of cyclolinear polymethylcarbosiloxanes with different design of monomer units were studied as well. It was revealed that all polymers form monomolecular films at the air/water interface, excluding those having longer hydrophobic fragment than hydrophilic ones. The ability to form multilayers depends on the surroundings of Si atom in the bridge between the cycles.

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Synthesis of CL PMCS III–V.
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f12-ijms-14-18215: Synthesis of CL PMCS III–V.

Mentions: Cyclolinear polyorganocarbosiloxanes with ethylene groups instead of oxygen atoms >SiMeOMeSi< as bridges between rings were synthesized by the polyaddition reaction of dihydridocycloorganotetra(hexa,octa)siloxanes with divinylcycloorganotetra(hexa)siloxanes bearing methyl and ethyl substituents in the presence of platinum complex catalysts (the Karstedt and Speier catalysts, dicyclopentadienylplatinum dichloride) and their reduced forms following Scheme 1 [17].


Self-organizing cyclolinear organosilicon polymers in bulk and on the surface of water.

Makarova NN, Astapova TV, Buzin AI, Polishchuk AP, Chizhova NV, Petrova IM - Int J Mol Sci (2013)

Synthesis of CL PMCS III–V.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3794777&req=5

f12-ijms-14-18215: Synthesis of CL PMCS III–V.
Mentions: Cyclolinear polyorganocarbosiloxanes with ethylene groups instead of oxygen atoms >SiMeOMeSi< as bridges between rings were synthesized by the polyaddition reaction of dihydridocycloorganotetra(hexa,octa)siloxanes with divinylcycloorganotetra(hexa)siloxanes bearing methyl and ethyl substituents in the presence of platinum complex catalysts (the Karstedt and Speier catalysts, dicyclopentadienylplatinum dichloride) and their reduced forms following Scheme 1 [17].

Bottom Line: It was shown that on introduction of CH2 groups into the methylcyclohexasiloxane unit, the polymer retains the ability to self-organize with formation of a mesomorphic state in a wide temperature range, while on introduction of (CH2)2 fragments in a cyclotetrasiloxane unit or in a bridge connecting two methylcyclotetra(hexa)siloxane units it does not.It was revealed that all polymers form monomolecular films at the air/water interface, excluding those having longer hydrophobic fragment than hydrophilic ones.The ability to form multilayers depends on the surroundings of Si atom in the bridge between the cycles.

View Article: PubMed Central - PubMed

Affiliation: Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova str., Moscow 119991, Russian Federation. buzin@cc.nifhi.ac.ru.

ABSTRACT
Cyclolinear organocarbosiloxane polymers with varying content and location of (CH2)n groups in the monomer unit were synthesized by reactions of heterofunctional polycondensation and polyaddition of difunctional organocyclosiloxanes and organocyclocarbosiloxanes. Their bulk properties were studied by differential scanning calorimetry and X-ray structural analysis. It was shown that on introduction of CH2 groups into the methylcyclohexasiloxane unit, the polymer retains the ability to self-organize with formation of a mesomorphic state in a wide temperature range, while on introduction of (CH2)2 fragments in a cyclotetrasiloxane unit or in a bridge connecting two methylcyclotetra(hexa)siloxane units it does not. Comparison of the X-ray data of dihydroxy derivatives of decamethylcyclohexasiloxane and decamethyl-5-carbocyclohexasiloxane with packing of cyclolinear organosilicon polymers in bulk shows that the polymer inherits the layered type of crystalline structure typical for monomers. Langmuir films of cyclolinear polymethylcarbosiloxanes with different design of monomer units were studied as well. It was revealed that all polymers form monomolecular films at the air/water interface, excluding those having longer hydrophobic fragment than hydrophilic ones. The ability to form multilayers depends on the surroundings of Si atom in the bridge between the cycles.

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