Moisture-curing polyurethane resins modified by multi-hydroxymethylated phenol

Abstract

Purpose

The purpose of this paper is to investigate the effects of multi-hydroxymethylated phenol (MHMP) on the properties of moisture-curing polyurethane (PU) resin, especially on the heat resistance.

Design/methodology/approach

The MHMPs with various active sites from 2.52 to 3.91 were synthesised and used as a modifier. The bond test (according to the JIS K6806-2003 standard) and thermogravimetric analysis (TGA) were used, respectively, to characterise the bond durability and heat resistance of MHMP-modified PU resin.

Findings

The MHMP with various F/P mole ratios had great effects on the properties of resultant PU resins. The increase of active sites of MHMP can improve the water resistance of resin due to the more cross-linking densities, while the decrease of active sites of MHMP can improve heat resistance of resin because more stable benzene ring introduced into the PU backbone.

Research limitations/implications

In cases where heat resistance of the PU resin is of primary concern, the use of MHMP with fewer active sites or a lower F/P ratio is recommended. In other cases where bond durability is focussed, the modifier MHMP shall be synthesised with higher F/P ratio.

Practical implications

MHMP as a modifier can be used to improve the heat resistance of PU resin.

Originality/value

The MHMPs with various hydroxymethyl groups were synthesised and used as modifier of moisture-curing PU resins to improve their heat resistance.

Citation

Zhang, X., Wei, S. and Gao, Z. (2014), "Moisture-curing polyurethane resins modified by multi-hydroxymethylated phenol", Pigment & Resin Technology, Vol. 43 No. 2, pp. 69-74. https://doi.org/10.1108/PRT-12-2012-0087