ScienceAsia 25 (1999) : 035-041 |doi: 10.2306/scienceasia1513-1874.1999.25.035

Chemical Constituents of Fissistigma polyanthoides

A Kongkaew^a,b and J Wootthikanokkhan^a,*

ABSTRACT: The polymerization of isoprene through the use of benzyl N,N-diethyldithiocarbamate (BDC) as an iniferter was investigated. The monomer concentration used was kept constant at 2.8 mol/L while the BDC concentration was varied. The polymer product was characterized by Fourier Transform Infrared Spectroscopy (FTIR), Proton Magnetic Resonance (¹H-NMR), and Differential Scanning Calorimetry (DSC) and the results showed that the product was mainly 1,4-polyisoprene. The molecular weight, polydispersity, and percentage yield of the polyisoprene obtained were affected by the BDC concentration. The percentage yield did not increase linearly with the BDC concentration but increased initially and then decreased after a critical BDC concentration was reached. The molecular weight of the polyisoprene decreased with BDC concentration. The polydispersity ranged between 1.8 and 4.7 and decreased with increasing BDC concentration.

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a Division of Materials Technology, School of Energy and Materials, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
b Department of Science Service, Ministry of Science, Technology and Environment, Bangkok 10400, Thailand.

* Address for Correspondence.

Received 5 Mar 1999