In Situ Investigation on the Formation Mechanism of MCM-41 Mesoporous Silica by Microcalorimetry

Abstract The preparation method of a polymer composite and the filler loading are amongst the factors that influence the properties of the final composites. This article studies the effect of these factors on the thermal stability and thermal degradation kinetics of poly(methyl methacrylate) (PMMA)/mesoporous silica (MCM-41) composites filled with small amounts of MCM-41. The PMMA/MCM-41 composites were prepared through in situ polymerisation and melt mixing methods, with MCM-41 loadings of 0.1, 0.3, and 0.5 wt.%. The presence of MCM-41 increased the thermal stability of PMMA/MCM-41 composites prepared by melt mixing, but in the case of the in situ polymerised samples, the MCM-41 accelerated the degradation of the polymer. As a result, the activation energy was low and less energy was required to initiate and propagate the degradation process of these composites. The small-angle X-ray scattering (SAXS) measurements showed that the preparation method of the composites had no influence on the pore size of MCM-41, but the PMMAs used in the two methods both had shorter chains than the MCM-41 pore size. This allowed the polymer chains to be trapped inside the pores of the filler and be immobilised, as was observed from nuclear magnetic resonance (NMR) spectroscopy. The immobilisation of the polymer chains was more significant in the in situ polymerised samples.

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Investigation on Mn-loaded mesoporous silica MCM-41 prepared via reducing KMnO4 with in situ surfactant

Microporous and Mesoporous Materials ◽

10.1016/j.micromeso.2005.02.006 ◽

2005 ◽

Vol 81 (1-3) ◽

pp. 235-240 ◽

Cited By ~ 26

Author(s):

Xiaoping Dong ◽

Weihua Shen ◽

Yufang Zhu ◽

Liangmin Xiong ◽

Jinlou Gu ◽

...

Keyword(s):

Mesoporous Silica ◽

Mcm 41

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The use of in situ and ex situ techniques for the study of the formation mechanism of mesoporous silica formed with non-ionic triblock copolymers

Chemical Society Reviews ◽

10.1039/c2cs35298b ◽

2013 ◽

Vol 42 (9) ◽

pp. 3777-3791 ◽

Cited By ~ 21

Author(s):

Tomas Kjellman ◽

Viveka Alfredsson

Keyword(s):

Mesoporous Silica ◽

Formation Mechanism ◽

Triblock Copolymers ◽

Ex Situ

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Photoluminescence of Poly(P-Phenylene Vinylene) Encapsulated in Mesoporous Silica

MRS Proceedings ◽

10.1557/proc-558-319 ◽

1999 ◽

Vol 558 ◽

Cited By ~ 1

Author(s):

Andras G. Pattantyus-Abraham ◽

Michael O. Wolf

Keyword(s):

Thermogravimetric Analysis ◽

Mesoporous Silica ◽

In Situ Polymerization ◽

Nitrogen Adsorption ◽

Phenylene Vinylene ◽

Polymer Loading ◽

Nitrogen Adsorption Isotherms ◽

Spectrum Matching ◽

Mcm 41

ABSTRACTThe preparation of poly(p-phenylene vinylene) (PPV) encapsulated in a mesoporous silica, MCM-41, is reported. In situ polymerization of xylylene bis(tetrahydrothiophenium chloride) yields a highly luminescent, yellow powder with a fluorescence spectrum matching that of unencapsulated PPV. Nitrogen adsorption isotherms show that the pore size of the PPV- loaded MCM-41 is significantly smaller than that of empty MCM-41 and a polymer loading of ca. 8% by weight is obtained by thermogravimetric analysis. Photoluminescence data for the encapsulated PPV are presented.

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