Thermal behavior and molecular simulation of liquid crystalline polymers containing a pentamethylenic spacer

Damian, Cristina; Hurduc, Nicolae; Shanks, Robert A.; Yarovsky, Irene; Pavel, Dumitru

doi:10.1016/s0927-0256(03)00036-3

Cited by 10 publications

(7 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, it plays a crucial role in thermotropic materials due to the liquid crystal ordering that occurs in a certain temperature range. There are several publications on the thermal stability of the polymeric liquid crystals [69][70][71][72][73][74][75]. They allow better understanding of the degradation processes due to their simpler molecular structure, and their systematic study may contribute important information [76,77].…”

Section: Ferrocene-containing Liquid Crystalline Polymersmentioning

confidence: 99%

Organometallic Ferrocene- and Phosphorus-Containing Polymers: Synthesis and Characterization

Hussein

Asiri

2012

Designed Monomers and Polymers

View full text Add to dashboard Cite

The inclusion of organometallic units into polymeric structures has attracted much attention in different fields according to the nature and behaviour of the inserted metal. Moreover, the discovery of organometallic polymers and their structural characterization initiated an explosive rebirth of organometallic chemistry. Organometallic moieties are in or pendent to the polymer backbone and examine some of the uses of the emergent metallocene polymers, and new uses are still being found for these remarkable organometallic moieties. This review gives a simple introduction to variable organometallic molecules and their characteristics. This review will focus on the syntheses and characterization of organometallic polymers, including ferrocene-and phosphorus-containing polymers. A general overview on ferrocene polymers with a special attention to ferrocene-containing liquid crystalline polymers (including a ferrocene moiety in the main chain, side-chain or dendrimers) and fullerene-ferrocene liquid crystalline polymers is presented. In addition, more details for synthesis and properties of phosphorus-containing polymers are illustrated.

show abstract

Section: Ferrocene-containing Liquid Crystalline Polymersmentioning

confidence: 99%

Organometallic Ferrocene- and Phosphorus-Containing Polymers: Synthesis and Characterization

Hussein

Asiri

2012

Designed Monomers and Polymers

View full text Add to dashboard Cite

show abstract

“…In most cases the mesophase range was quite large, being about 50 2 C or more. As all the polymers containing DHAB segments began to decompose above 250 2 C, a very careful thermogravimetric study was necessary [17][18][19]. Figure 1 presents the DSC thermograms of samples 1, 2, 3, 5 and 13.…”

Section: Aromatic Polyethers Containing Different Spacers 153mentioning

confidence: 99%

“…However, all the samples containing DHAB and DHD units (16)(17)(18)(19)(20)(21) showed liquid crystalline properties, the transition temperatures decreasing with the increase of DHD content.…”

Section: Aromatic Polyethers Containing Different Spacers 153mentioning

confidence: 99%

“…For samples [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] in which the spacer had eight methylene units we continued the study of the influence of the length of the spacer and structure of the bisphenols over the capacity of generating a mesophase. We used the same combination of bisphenols as in the case of the hexamethylene spacer, with the exception of TDP which was replaced by KDP, a less flexible bisphenol, but with a slightly higher polarity.…”

Section: Aromatic Polyethers Containing Different Spacers 153mentioning

confidence: 99%

See 1 more Smart Citation

Liquid Crystalline Polymers. 15. Synthesis and Thermal Behavior of Some Aromatic Polyethers Containing Different Spacers

Alazaroaie¹,

Catanescu²,

Pavel

et al. 2005

High Performance Polymers

Self Cite

View full text Add to dashboard Cite

A series of aromatic homo-and copolyethers containing 6, 7 or 8 methylenic groups as spacers are presented. The polymers were synthesized by phase-transfer catalysis and they were characterized by using 1 H-NMR, polarized light microscopy, differential scanning calorimetry and thermogravimetric analyses. All copolymers have low molecular weight, situated within the oligomer domain. They have high transition temperatures except for the case when bent or semi-flexible bisphenols were used as comonomers. Only 4,4 1 -dihydroxyazobenzene-based polymers showed liquid crystalline properties with a mesophase range over 50 2 C, and with the clearing temperatures situated near their thermal decomposition limit. The insertion of kink or flexible bisphenols was not favorable to mesophase formation (it induced too high a disorder in the system), but it lowered the transition temperatures, as expected. Few exceptions occurred in the case of bisphenol A and 4,4 1 -dihydroxybenzophenone. The biphasic nature of these copolyethers is most probably due to both the polydispersity and the chemical heterogeneity of the samples. Some of the semi-crystalline copolymers may exhibit virtual mesophase that can be uncovered by increasing their molecular weight or by raising the free energy of the isotropic liquid state.

show abstract

“…And the predicted values of T g 's slightly departed from the experimental results. Damian et al 6 also studied the thermal stability of some aromatic polyethers containing a pentamethylenic spacer by molecular simulation. Computersimulated properties of the investigated polymers, such as order parameter and polarity of polymers, were all in good agreement with the experimental values.…”

Section: Introductionmentioning

confidence: 99%

Effect of molecular structures on polyimide properties: Comparison between estimations and experiments

Chen

Zhang

et al. 2006

J of Applied Polymer Sci

View full text Add to dashboard Cite

The density and glass transition temperature (T g ) of 11 polyimides were investigated by experiments and predictions using the connectivity indices method to explore the structure-property relationships. The predicted results are in good agreement with the experimental data. The mean interchain spacings (d-spacings) of polyimides increase with the introduction of bridging groups, i.e., following the order: PDA < BZD < ODA < MDA < BDAF, while the densities increase in the order of MDA < BZD < PDA, and cohesive energy densities (CEDs) of polyimides change following the order of BDAF < MDA < ODA < BZD < PDA. In addition, the glass transition temperatures (T g 's) increase as the CEDs increase for the polyimides prepared from the same dianhydride and different diamines, whereas no certain correlation exists between T g 's and the values of the characteristic ratio (C 1 ). This indicates that the strength of interchain interaction influences the T g 's of polyimides much stronger than the chain flexibility.

show abstract

Thermal behavior and molecular simulation of liquid crystalline polymers containing a pentamethylenic spacer

Cited by 10 publications

References 21 publications

Organometallic Ferrocene- and Phosphorus-Containing Polymers: Synthesis and Characterization

Organometallic Ferrocene- and Phosphorus-Containing Polymers: Synthesis and Characterization

Liquid Crystalline Polymers. 15. Synthesis and Thermal Behavior of Some Aromatic Polyethers Containing Different Spacers

Effect of molecular structures on polyimide properties: Comparison between estimations and experiments

Contact Info

Product

Resources

About