Chemical and Thermo-Mechanical Properties of Waterborne Polyurethane Dispersion Derived from Jatropha Oil.

Sariah Saalah,Syeed Saifulazry Osman Al Edrus,Suhaini Mamat,Emiliana Rose Jusoh,Min Min Aung,Dayang Radiah Awang Biak,Luqman Chuah Abdullah,Mek Zah Salleh,Mahiran Basri

doi:10.3390/polym13050795

Abstract

Nowadays, there is a significant trend away from solvent-based polyurethane systems towards waterborne polyurethane dispersions due to government regulations requiring manufacturers to lower total volatile organic compounds, as well as consumer preference for more environmentally friendly products. In this work, a renewable vegetable oil-based polyol derived from jatropha oil was polymerized with isophorone diisocyanate and dimethylol propionic acid to produce anionic waterborne polyurethane dispersion. Free standing films with up to 62 wt.% bio-based content were successfully produced after evaporation of water from the jatropha oil-based waterborne polyurethane (JPU) dispersion, which indicated good film formation. The chemical and thermo-mechanical properties of the JPU films were characterized. By increasing the OH numbers of polyol from 161 mgKOH/g to 217 mgKOH/g, the crosslinking density of the JPU was significantly increased, which lead to a better storage modulus and improved hydrophobicity. Overall, JPU produced from polyol having OH number of 217 mgKOH/g appears to be a promising product for application as a binder for wood and decorative coatings.

Highlights

Waterborne polyurethane (WBPU) is rapid growing segment of the polyurethane (PU) industry due to the increasing worldwide concern about the environmental conditions caused by the volatile organic compound (VOC) content in traditional polyurethane coatings
The results show excellent colloidal stability of the dispersion and the rheology is comparable to petrochemical-based WBPU [20]
The bio-based polyols with OH numbers ranging from 161 mgKOH/g to 217 mgKOH/g were polymerized with IPDI, dimethylol propionic acid (DMPA) and hydroxyethyl metachrylate (HEMA) to produce jatropha oil-based waterborne polyurethane (JPU) dispersion

Summary

Introduction

Waterborne polyurethane (WBPU) is rapid growing segment of the polyurethane (PU) industry due to the increasing worldwide concern about the environmental conditions caused by the volatile organic compound (VOC) content in traditional polyurethane coatings. WBPU contains hydrophilic ionic centres at its backbone to allow dispersion of hydrophobic PU in water, forming a stable colloid. These products fulfil many of the requirements related to conventional solvent-borne coatings, e.g., low viscosity at a high molecular weight and good applicability [3]. Commercial solvent-based polyurethane creates a yellowish or slightly amber-coloured plastic coating on the wooden surface and requires more time to dry [4]. Coating segments accounted for 47% of the total global consumption of polyurethane dispersion in 2016, and the share is expected to grow at a CAGR of 6.98% by 2023 [5]

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Results

Conclusion