fulltext.study @t Gmail

Silica/clay organo-heterostructures to promote polyethylene–clay nanocomposites by in situ polymerization

Paper ID Volume ID Publish Year Pages File Format Full-Text
40389 45852 2013 9 PDF Available
Title
Silica/clay organo-heterostructures to promote polyethylene–clay nanocomposites by in situ polymerization
Abstract

Two clay organo-heterostructures have been prepared and employed as fillers and catalyst supports for the development of polyethylene–clay nanocomposites. The new silica–clay organo-heterostructures have been obtained from two organoclays modified with tetramethoxysilane. In contrast to related heterostructures reported previously the organic moieties are not removed by heating and their presence intends to confer hydrophobicity to the interlayer region of the clay, even after delamination by hydrolysis-polymerization of the alkoxysilane takes place. These organo-heterostructures were used for preparing clay–polyethylene nanocomposites by in situ polymerizations in which the organo-heterostructures were added together with the metallocene catalyst, and by using the silica–clay as support for the metallocene catalysts. The polymers formed when the organo-heterostructures were used as support for the catalyst have higher molecular weights than the standard polyethylene formed under homogeneous conditions. Moreover, the presence of the inorganic silica network developed in the interlayer region of the organoclay favours the existence of a larger organophilic region in which it is possible to accommodate both the catalyst and the monomer, and hence when the polymer grows in this environment it can assist in the exfoliation of the clay layers inside the polyethylene matrix. The polymer particle morphology improved with the presence of the clay in the polymerization. The molecular weight for support systems presented an increasing ca. 40% compared to neat PE, and by TEM it was found that the clay layers were well dispersed in the PE matrix.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (160 K)Download as PowerPoint slideHighlights► Organo-heterostructures were used for preparing clay–polyethylene nanocomposites by in situ polymerizations. ► The catalytic activities of supported systems were comparable to a homogeneous system. ► The polymer particles morphology improved with the presence of the clay in the polymerization. ► The molecular weight of the polymers increase for the supported systems.

Keywords
Metallocene catalysts; Clay-based heterostructures; Polymer–clay nanocomposites; Polyethylene; Support catalysts
First Page Preview
Silica/clay organo-heterostructures to promote polyethylene–clay nanocomposites by in situ polymerization
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 453, 26 February 2013, Pages 142–150
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us