Synthesis of polyisoprene-grafted silicas by free radical photopolymerisation of isoprene initiated from silica surface

Chi N.H.T., . and Daniel D., . Synthesis of polyisoprene-grafted silicas by free radical photopolymerisation of isoprene initiated from silica surface. pp. 78-96. ISSN 1511-1768

Synthetic silicas are used increasingly in tyre tread compounds. However their use as fillers for hydrophobic rubbers (synthetic polydienes natural rubber) is questionable unless a silane-coupling agent is introduced to bind the silica to the rubbers and to prevent it from interfering with the reaction mechanism of the sulphur-cure system. In order to improve the interphase strengths between silica and hydrophobic rubber as well as to suppress the effects of silanol groups on sulphur-cured systems polyisoprene-grafted silicas were synthesised. The principle of the synthesis was based on the living radical photopolymerisation initiated from the silica surface. For that a two-step procedure was adopted. First silica particles were functionalised with N N-diethyldithiocarbamate iniferter groups by using a SN2 substitution of chlorine atoms previously bound on silica surface. Following this photopolymerisation of isoprene was carried out from the N N-diethyldithiocarbamate iniferter groups and the polymerisation progress was simultaneously followed by HPLC and NMR. Functionalised silicas and polyisoprene-grafted silicas were characterised by solid-state 13C and 29Si CP/MAS NMR.

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Abstract

Synthetic silicas are used increasingly in tyre tread compounds. However their use as fillers for hydrophobic rubbers (synthetic polydienes natural rubber) is questionable unless a silane-coupling agent is introduced to bind the silica to the rubbers and to prevent it from interfering with the reaction mechanism of the sulphur-cure system. In order to improve the interphase strengths between silica and hydrophobic rubber as well as to suppress the effects of silanol groups on sulphur-cured systems polyisoprene-grafted silicas were synthesised. The principle of the synthesis was based on the living radical photopolymerisation initiated from the silica surface. For that a two-step procedure was adopted. First silica particles were functionalised with N N-diethyldithiocarbamate iniferter groups by using a SN2 substitution of chlorine atoms previously bound on silica surface. Following this photopolymerisation of isoprene was carried out from the N N-diethyldithiocarbamate iniferter groups and the polymerisation progress was simultaneously followed by HPLC and NMR. Functionalised silicas and polyisoprene-grafted silicas were characterised by solid-state 13C and 29Si CP/MAS NMR.

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Item Type:	Article
AGROVOC Term:	Isoprene
AGROVOC Term:	Synthetic polymers
AGROVOC Term:	Natural rubber
AGROVOC Term:	Polymerization
AGROVOC Term:	Mechanical properties
AGROVOC Term:	Thermal properties
AGROVOC Term:	Cross-linking
AGROVOC Term:	Silica
Depositing User:	Ms. Suzila Mohamad Kasim
Last Modified:	24 Apr 2025 06:28
URI:	http://webagris.upm.edu.my/id/eprint/23062

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