Properties of waterborne polyurethane films: effects of blend formulation with hydroxyl telechelic natural rubber and modified rubber seed oils

Abstract

A series of new waterborne polyurethanes (WPUs) was successfully prepared by the prepolymer process from the bio-renewable sources hydroxytelechelic natural rubber (HTNR with MW 3000 g mol −1 ) and hydroxylated rubber seed oil (HRSO), with DMPA fixed at 5.6 wt%. The effects of ratio of HTNR and HRSO (ranging from 1.00/0 to 0.10/ 0.90) and of hydroxyl value (OHV) of HRSO (200 or 270 mgKOH/g) on final properties were studied. It was found that the particle size of WPU increased significantly with both HRSO/HTNR ratio and OHV of HRSO. Chemical structure of the WPU films was confirmed by FT-IR. The water uptake, mechanical, dynamic mechanical properties and thermal stability of WPU film improved with both HRSO content and OHV of HRSO, while swelling in THF decreased. All these WPU films had similar Tg. This article reports novel green biobased WPU with promising applications as adhesive for shoe industries.

Future opportunities for bio-based adhesives – advantages beyond renewability

“…A similar result was obtained by Saetung et al, who made a polyurethane dispersion to be used as an adhesive for shoes. 74 The dispersion was made from mixtures of hydroxytelechelic natural rubber (HTNR) and hydroxylated rubber seed oil (HRSO), dimethylolpropionic acid (DMPA) and toluene-2,4-diisocyanate (TDI), shown in Fig. 14. It was then tested for water uptake in film form.…”

A Review of the Sustainable Approaches in the Production of Bio-based Polyurethanes and Their Applications in the Adhesive Field

“…Water-based polyurethane dispersions, also known as waterborne polyurethanes (WPU), allow for the replacement of the traditional solvent-borne polyurethanes, thus reducing the environmental impact, as revealed by the comprehensive approach of the life cycle assessment conducted by Maciel et al [144], besides exhibiting some beneficial advantages, inter alia versatile structure-properties relationship and good processability and elasticity [145,146].…”

“…9 Soybean oil-based diisocyanates synthesis reported by Hojabri et al a [141] and b [44] The significant impact of the design of such sustainable synthetic route becomes noticeable in studies as that conducted by Li et al [14], revealing the preparation of polyurethane systems with around a 90% of renewable content, owing to the combination of WPU synthesis procedure with the utilization of renewable resources, namely isosorbide polyol and fatty acid-based isocyanate. Additionally, Zhou et al [131] and Cakić et al [130], for their part, properly incorporated recycled PET bottles in the polyurethane structure via glycolysis, whereas Saetung et al [146] used polyols based on natural rubber and rubber seed oil acting as the starting materials for renewable WPU for application in the footwear industry.…”

A new UV‐curable biodegradable waterborne polyurethane‐acrylate based on natural rubber blended with cassava starch

“…The recent trends and development of biobased WPU from renewable resource has a growing tendency to produce green polyurethane materials. Many studies have reported the successful synthesis of WPU based on bio‐polyol from vegetable oils, including soybean oil, 7,8 castor oil, 9 jatropha oil, 10 rapeseed oil, 11 and rubber seed oil 12 . In addition, these bio‐polyols exhibit biodegradability due to ester bonds of triglycerides which readily catalyze hydrolysis by the esterase enzymes 13 .…”