Exfoliation of layered silicate facilitated by ring-opening reaction of cyclic oligomers in PET–clay nanocomposites

Lee, Sang Soo; Tae, Young; Rhee, Hee Woo; Kim, Junkyung

doi:10.1016/j.polymer.2005.01.006

Cited by 53 publications

(55 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[7]). Few reports are even available in the open literature on the polymerization of CBT or similar cyclic polyesters in presence of organoclays [8][9]. Further information about the feasibility of this approach can be taken from the patent literature (e.g.…”

Section: Introductionmentioning

confidence: 99%

Melting and crystallization of in-situ polymerized cyclic butylene terephthalates with and without organoclay: a modulated DSC study

Karger‐Kocsis¹,

Shang²,

Ishak³

et al. 2007

Express Polym. Lett.

View full text Add to dashboard Cite

Abstract. The polymerization of cyclic butylene terephthalate oligomers (CBT) were studied in presence (in 5 wt.%) and absence of an organoclay (Cloisite ® 30B) by modulated DSC (MDSC). The organoclay containing samples were produced by dry and melt blending, respectively. The first heating, causing the polymerization of the CBT catalyzed by an organotin compound, was followed by cooling prior to the second heating. The MDSC scans covered the temperature interval between 0 and 260°C. The aim of this protocol was to study the crystallization and melting behavior of the resulting polybutylene terephthalate (pCBT) and its organoclay modified nanocomposites. It was found that the thermal behaviors of the polymerizing and polymerized CBT (pCBT) were strongly affected by the sample preparation. The organoclay suppressed the crystallization of the pCBT produced during the first heating. However, results from the second heating suggest that more perfect crystallites were formed in the organoclay modified pCBT variants. The organoclay also affected the conversion and mean molecular mass of the resulting pCBT which were slightly lower than those of the plain pCBT polymerized under identical conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

Melting and crystallization of in-situ polymerized cyclic butylene terephthalates with and without organoclay: a modulated DSC study

Karger‐Kocsis¹,

Shang²,

Ishak³

et al. 2007

Express Polym. Lett.

View full text Add to dashboard Cite

show abstract

“…Huang et al [23] reported the preparation of partially exfoliated PC/clay nanocomposites using cyclic carbonate oligomers. It is well known [24,25] that the migration of low molecular weight cyclic carbonate oligomers into the clay galleries favor the exfoliation of the clay and also in this case a partially exfoliated morphology was obtained. Suin and coworkers [26,27] have recently reported a method to produce optically transparent polycarbonate nano composites by solvent casting and melt blending.…”

mentioning

confidence: 73%

Effect of telechelic ionic groups on the dispersion of organically modified clays in bisphenol A polycarbonate nanocomposites by in-situ polymerization using activated carbonates

Colonna¹,

Acquasanta²,

Gioia³

et al. 2017

Express Polym. Lett.

View full text Add to dashboard Cite

Polymer layered nanocomposites (polymeric matrixes filled with particles that have one of their dimension in the nanometer range) [1,2] often have superior physical and mechanical properties over their microcomposites counterparts, including improved modulus [3], reduced gas permeability [4], increased flame retardantcy [5,6] and lower thermal expansion [7]. A considerable amount of the work in this area has been focused on polymeric nanocomposites containing layered silicates such as montmorillonite clay (MMT) [8][9][10]. A large number of papers have reported the preparation of well-exfoliated polymer/clay nanocomposites [9][10][11][12][13][14]. However, several problems have been encountered in the preparation of bisphenol A polycarbonate (PC) nanocomposites. For example, Paul [15] reports that only a small fraction of the clay platelets are exfoliated while the main part of the PC/clay composites has an intercalated morphology. The reason of this low degree of dispersion has been ascribed to the poor compatibility between the clay surface and the polymer. Moreover, the PC/clay composites prepared by melt blending of PC with montmorillonite modified with ammonium clays [15] are always dark colored and the molecular weight of the PC matrix consistently (30-40%) drops after extrusion. This issue has been ascribed to the use of ammonium salts for the modification of the clay (which are used in order to increase its compatibility of the clay with the polymer matrix).Indeed, ammonium modified clays are not stable in the standard polycondensation and processing conditions of PC that can exceed 300°C. Abstract. Nanocomposites of bisphenol A polycarbonate with organically modified clays have been prepared for the first time by in-situ polymerization using bis(methyl salicyl) carbonate as activated carbonate. The use of the activated carbonate permits to conduct the polymerization reaction at lower temperature and with shorter polymerization time with respect to those necessary for traditional melt methods that uses diphenyl carbonate, affording a nanocomposite with improved color. Moreover, an imidazolium salt with two long alkyl chains has been used to modify the montmorillonite, providing an organically modified clay with high thermal stability and wide d-spacing. The addition of ionic groups at the end of the polymer chain increases the interaction between the clay surface and the polymer producing a better dispersion of the clay. The presence of the clay increases the thermal stability of the polymer.

show abstract

“…13 Similarly, the low viscosity of the melted oligomers is advantageous for the production of polymer nanocomposites with improved properties since nanofiller distribution and dispersion is typically enhanced by reducing the matrix viscosity. 14 Moreover, the intercalation and exfoliation of layered nanofillers such as organoclay or graphene is also enhanced if the matrix viscosity is decreased. [15][16] In this review article the recent advances in the processing-structure- …”

Section: / 107mentioning

confidence: 99%

“…[134][135][136][137][138] An increasing amount of reports on pCBT/organoclay nanocomposites can also be found. 14,65,[139][140][141][142][143][144][145][146] The low viscosity of molten or dissolved oligomers is utilized to obtain a CBT-intercalated organoclay. Subsequent ROP causes then an increase in interlayer distance along with the disintegration of the layered clay structure, as shown in figure 22.…”

Section: Physical Blendingmentioning

confidence: 99%

A Review of the Recent Advances in Cyclic Butylene Terephthalate Technology and its Composites

Abt

Sánchez‐Soto

2016

Critical Reviews in Solid State and Materials Sciences

View full text Add to dashboard Cite

Exfoliation of layered silicate facilitated by ring-opening reaction of cyclic oligomers in PET–clay nanocomposites

Cited by 53 publications

References 42 publications

Melting and crystallization of in-situ polymerized cyclic butylene terephthalates with and without organoclay: a modulated DSC study

Melting and crystallization of in-situ polymerized cyclic butylene terephthalates with and without organoclay: a modulated DSC study

Effect of telechelic ionic groups on the dispersion of organically modified clays in bisphenol A polycarbonate nanocomposites by in-situ polymerization using activated carbonates

A Review of the Recent Advances in Cyclic Butylene Terephthalate Technology and its Composites

Contact Info

Product

Resources

About