Glass Transitions of the Poly-(n-Alkyl Methacrylates)

Rogers, Senta S.; Mandelkern, L.

doi:10.1021/j150553a033

Cited by 312 publications

(178 citation statements)

References 25 publications

Supporting

Mentioning

153

Contrasting

Unclassified

Order By: Relevance

“…and second, to those already published in the literature [8,9] Side-chain liquid crystalline polymers have been described as presenting first-order transitions between mesophases and the isotropic melt, and also glass transitions frequently occurring in the temperature range of the mesomorphic phases [12]. To detect these, DSC measurements were carried out systematically on all of the PM-n and PM-m-EO polymers, and on the MC-n model compounds, from below room temperature to generally at least thirty degrees above the clearing temperature.…”

mentioning

confidence: 84%

Thermal properties of a series of side-chain liquid crystalline poly(methacrylates)

et al. 1988

View full text Add to dashboard Cite

Résumé. 2014 Abstract. 2014 The thermal behaviour of a series of side-chain liquid crystalline poly(methacrylates) has been investigated by thermogravimetry, differential scanning calorimetry, polarizing optical microscopy, and dilatometry. The DSC study has shown that long times are required to reach equilibrium even at temperatures above the glass transition. The thermotropic polymorphism has been determined as a function of the length of the flexible spacer. Glass transitions in the mesomorphic state have been discussed. Dilatometry has shown that, for the « glassy » mesomorphic phases, the partial specific volume of the flexible spacer is close to that corresponding to the crystalline state ; that, for the normal liquid crystalline phases, it is intermediate between those corresponding to the crystal and the isotropic liquid ; and that, for the isotropic polymer, it is close to that of a liquid.

show abstract

mentioning

confidence: 84%

Thermal properties of a series of side-chain liquid crystalline poly(methacrylates)

et al. 1988

View full text Add to dashboard Cite

show abstract

“…32 It has been observed that the size and flexibility of side groups can alter the T g of polymers. 33,34 As a result, a high-T g polymer was obtained by introducing trans-stilbene units into the side chain, because the trans-stilbene units inhibit the motions of the molecular chains and reduce chain mobility. We estimated that high-T g polymer could be obtained by introducing anisotropic molecule having a rod-like form of a size that is similar to or larger than that of trans-stilbene into the side chain.…”

Section: Discussionmentioning

confidence: 99%

Design and synthesis of a zero-photoelastic birefringence polymer with a high glass-transition temperature by a random copolymerization method

Shafiee

Tagaya

Koike

2011

Polym J

View full text Add to dashboard Cite

We designed and synthesized a zero-photoelastic birefringence polymer that had a high glass-transition temperature (T g ) by introducing trans-stilbene units into the side chains of the copolymer by a random copolymerization method. The concentration of the trans-stilbene units required to compensate for photoelastic birefringence in the random copolymer was lower than that required in a polymer prepared by an anisotropic molecule dopant method, because the presence of an anisotropic moiety in the side chain of the polymer has a greater effect than an anisotropic molecule doped in the polymer. Furthermore, the polymer with trans-stilbene units in side chains showed a higher T g than the polymer containing an anisotropic dopant. We conclude that the introduction of an anisotropic molecule of a similar or larger size to trans-stilbene into the side chain gives a polymer with a high T g .

show abstract

“…The presence of long flexible n-alkyl substituents has a significant effect on flexibility of macromolecules, including poly (alkylstyrenes) [32], polyacrylates [33] and polymethacrylates [34]. As the length of the n-alkyl side chain increases, flexibility increases within each of these families of polymers.…”

Section: Elasticity Of Cema-oda Networkmentioning

confidence: 99%

“…In other words, the flexibility of the network increases with incorporation of MM rather than AM crosslinker. Polymethacrylates have a total of four flexible bonds per monomer unit, polyacrylates three while polystyrene has only two since the rotation of the benzene ring (CEMA) about the bond connecting it to the polymer backbone does not give a configurationally distinguishable position [34]. Given the chemical structures of MM and AM crossklinkers, the crosslinker based on methacryl groups leads to more flexible networks than that based on acrylate.…”

Section: Elasticity Of Cema-oda Networkmentioning

confidence: 99%

Synthesis and Characterization of Porous Crosslinked Copolymers for Oil Spill Sorption

et al. 2007

View full text Add to dashboard Cite

Cinnamoyloxy ethyl methacrylate (CEMA) was copolymerized with different monomer feed ratios of octadecyl acrylate (ODA) and crosslinked using azobisisobutyronitrile (AIBN) as the initiator and N,N',N"-trisacryloyl melanine (AM) or N,N',N",-trismethacryloylmelanine (MM) crosslinkers. The networks are characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). For crosslinked CEMA/ODA copolymer sol fraction values are lower when MM is used rather than AM. The thermal stability of crosslinked network increases with increasing ODA concentration and also in the presence of MM crosslinker, a consequence of higher crosslinking density. SEM results show a porous structure; micropores are formed when ODA contents increases. According to DMA results, the flexibility of the network is enhanced by incorporation of MM rather than AM. Since our crosslinked networks are both flexible and porous, they are applicable as oil sorber networks to alleviate pollution from oil spills.

show abstract

Glass Transitions of the Poly-(n-Alkyl Methacrylates)

Cited by 312 publications

References 25 publications

Thermal properties of a series of side-chain liquid crystalline poly(methacrylates)

Thermal properties of a series of side-chain liquid crystalline poly(methacrylates)

Design and synthesis of a zero-photoelastic birefringence polymer with a high glass-transition temperature by a random copolymerization method

Synthesis and Characterization of Porous Crosslinked Copolymers for Oil Spill Sorption

Contact Info

Product

Resources

About