Effect of hard segments content on the properties, structure and biodegradation of nonisocyanate polyurethane

Abstract

The present study investigates the biodegradation of synthesized condensation nonisocyanate polyurethanes (NIPUs). It was prepared by reacting phenol sulphonic acid and oligooxypropylene diol and formaldehyde and contained different amounts of hard segments (HSs). Polyurethane samples were submitted to biodegradation with microorganisms R-14 and in garden soil. The tensile strength (TS), relative elongation at break and weight loss of the prepared samples were evaluated and their structure and morphology analysed. It was found that maximum decrease of the TS of all tested NIPU samples occurred only after 7 days of biodegradation. Maximum TS decrease attained was approximately 70% and 75%, respectively, for NIPU based on 0.8-mol and 1-mol HS. Moreover, significant decrease of relative elongation at break and weight loss values after biodegradation in culture R-14 for NIPU samples based on 0.9-mol HS and 1-mol HS was observed. Fourier transform infrared and scanning electron microscopic results confirmed that biodegradation occurred in urea or urethane groups. The glass transition of HSs decreased by at least 20°C due to biodegradation, suggesting that this later took place almost only in the crystalline region of NIPU samples.

Greener Nanocomposite Polyurethane Foam Based on Sustainable Polyol and Natural Fillers: Investigation of Chemico-Physical and Mechanical Properties

“…As described before, in both cases, the produced PUs are partially renewable, because for PUs with bio-based polyols there is the isocyanate (synthetic precursor) and in the case of NIPU there are organic polyamines (synthetic precursor) [9,15,16].…”

“…Generally, the preparation of NIPU [15] occurs through a reaction (i.e., an environmental friendly polyaddition process or un-sustainable polycondensation or ring opening polymerization) of a polyamine with a cyclic carbonate, in which typically the amine comes from a petrochemical source and cyclic carbonate from sustainable sources (such as biomass, soybean and rapeseed oils, etc.) [9,16].…”

Biobased Polyurethane Foams Based on New Polyol Architectures from Microalgae Oil

“…For example, PU foams (PUFs) are mainly obtained from a blowing agent expansion during the polyaddition between a polyisocyanate and a polyol. The nonisocyanate PU is shown the interest by the scientific community for the elaboration of sustainable foams despite a slow process and low mechanical properties. − However, the substitution of fossil-based polyols in PUFs has received significant attention because of environmental and economic concerns. − The synthesis of polyols for PUFs derived from MAO has been only scarcely explored via two main pathways: (i) epoxidation and ring-opening by methanol, , ethylene glycol, and lactic acid and (ii) hydroformylation . The high potential of this bioresource for PUFs has mainly been demonstrated through these preliminary studies.…”

Upgrading Sustainable Polyurethane Foam Based on Greener Polyols: Succinic-Based Polyol and Mannich-Based Polyol

“…Sustainable resources such as biomasses can be used as a valuable and inexhaustible feedstock to produce several chemicals, as they are naturally renewable. In this context, the production of polyols from biomasses has been widely investigated worldwide in both academic institutions and industries, since they represent, along with polyisocyanates, the main components for the manufacturing of sustainable polyurethanes [ 1 , 2 , 3 , 4 , 5 ]. These polyols, obtained from biomass through fine chemical processes, represent an environmentally friendly alternative to the continuous depletion of fossil resources [ 6 , 7 ].…”