Surface Response Methodology-Based Mixture Design to Study the Influence of Polyol Blend Composition on Polyurethanes’ Properties

Abstract

Polyurethanes are materials with a strong structure-property relationship. The goal of this research was to study the effect of a polyol blend composition of polyurethanes on its properties using a mixture design and setting mathematic models for each property. Water absorption, hydrolytic degradation, contact angle, tensile strength hardness and modulus were studied. Additionally, thermal stability was studied by thermogravimetric analysis. Area under the curve was used to evaluate the effect of polyol blend composition on thermal stability and kinetics of water absorption and hydrolytic degradation. Least squares were used to calculate the regression coefficients. Models for the properties were significant, and lack of fit was not (p < 0.05). Fit statistics suggest both good fitting and prediction. Water absorption, hydrolytic degradation and contact angle were mediated by the hydrophilic nature of the polyols. Tensile strength, modulus and hardness could be regulated by the PE content and the characteristics of polyols. Regression of DTG curves from thermal analysis showed improvement of thermal stability with the increase of PCL and PE. An ANOVA test of the model terms demonstrated that three component influences on bulk properties like water absorption, hydrolytic degradation, hardness, tensile strength and modulus. The PEG*PCL interaction influences on the contact angle, which is a surface property. Mixture design application allowed for an understanding of the structure-property relationship through mathematic models.

Influence of Polyol/Crosslinker Blend Composition on Phase Separation and Thermo-Mechanical Properties of Polyurethane Thin Films

“…In this study, PEG and PCL were used as polyols, PE was used as the crosslinker, and IPDI was used as the isocyanate. PUs were synthetized by two-step polymerization as reported in previous work [2]. Briefly, PCL and PEG were dissolved in 10 mL of DMF, and the calculated amount of IPDI was added to the mixture.…”

“…Eight polyol/crosslinker blends were studied, and their composition was defined by a mixture design detailed in previous research [2]. The blend compositions are presented in Table 1.…”

“…PUs can be easily synthetized by the reactions of polyol with isocyanate and chain extenders or crosslinkers, creating a segmented structure composed of soft polyol chains and hard segments (HS), urethane bonds, isocyanate, and a chain extender or crosslinker. Physio-chemical and mechanical properties can be tuned based on the nature and structure of monomers [2]. Furthermore, microphases or domains composed by HS and soft segments (SS) are driven by thermodynamic incompatibility resulting in insolubility between HS and SS [3].…”

“…Also, mixing polyhydroxyalkanoates (PHA) diol and polyethylene glycol (PEG) produce a change in the crosslinking and the increase of PHA produces a crystalline region on Pus [8]. While, PEG incorporation in Poly(tetra-methylene glycol) (PTMG) PUs drive different phenomena according to the molecular weight, PEG of 200 g/mol did not differs from pure PTMG based PUs, while 2000 g/mol produces the best phase separation.In the past, we studied the influence of polyol crosslinker composition on polyurethane properties through a mixture design coupled with a surface response analysis [2]. There, we studied the physic-chemical and mechanical properties of PUs based on polycaprolactone diol and polyethylene glycol, as polyols, and pentaerythritol, as crosslinkers.…”

“…In the past, we studied the influence of polyol crosslinker composition on polyurethane properties through a mixture design coupled with a surface response analysis [2]. There, we studied the physic-chemical and mechanical properties of PUs based on polycaprolactone diol and polyethylene glycol, as polyols, and pentaerythritol, as crosslinkers.…”