Modified Polyetheramines in RIM

Abstract

Polyurea RIM, because of its production speed, internal release characteristics, high temperature dimensional stability, and increased resistance to water absorption is finally coming to the forefront as a better route to producing automotive body panels and fascia. One of the barriers that held back the rapid replacement of polyurethane-urea RIM by this new technology has been the increased reaction rate typically exhibited by polyurea RIM. The throughputs of existing RIM equipment were not high enough to produce some of the larger fascia and body panel parts.To address this need of some molders to process polyurea RIM in lower throughput RIM machines, we have investigated various modifications of our polyetheramines. Among the modifications investigated were the recently introduced ketimine technology, N-alkyl substituted polyetheramines and polyether amines having aromatic amine termination. The processing characteristics and physical properties of some of these slower polyether amines in polyurea RIM formulations will be discussed.

Single-Step Synthesis and Characterization of Non-Linear Tough and Strong Segmented Polyurethane Elastomer Consisting of Very Short Hard and Soft Segments and Hierarchical Side-Reacted Networks and Single-Step Synthesis of Hierarchical Hyper-Branched Polyurethane

“…The tertiary oligo-uret carbonyl-stretching absorbances accurately and consistently appear at 1688 cm −1 in all the spectra and are perfectly aligned with connecting red dashed line, annotated in Figure 15-these resonances are strongly consistent, with the exact same location of the tertiary oligo-uret FTIR carbonyl-stretching absorbance previously reported in polyurethanes, polyureas, hyper-branched polyurea [35][36][37][38], and in poly(hexamethylene oligo-uret) [38]. When viewing the adjacent urethane carbonylstretching absorbance, a shift from 1717 cm −1 (Figure 15b,c) to around 1710 cm −1 (with a slight shoulder/thickening at around 1717 cm −1 ) is observed, which most probably occurs due to hydrogen bonding, which is consistent with and within the very recently reported range for the hydrogen bonding-related shift of the urethane carbonyl-stretching absorbance [60]. The urethane carbonyl-stretching absorbance in the spectrum is observed to shift within this range (Figure 15a)-but no splitting is observed (Figure 15a-c).…”

“…The industrial synthesis of the polymer in appropriately shaped molds may provide further optimization, which will most probably lead to even higher tensile strength. A wellknown and commonly used industrial processing method for crosslinked polyurethanes and poly(urethane urea)s is reaction injection molding (RIM) [59,60]. Nevertheless, the occurrence of some flaws, imperfections, and internal stresses in the final product polymer is practically inevitable, even in highly optimized industrial injection molding processes [61].…”

Chemical Structure and Side Reactions in Polyurea Synthesized via the Water–Diisocyanate Synthesis Pathway

“…Due to the high nucleophilicity of the primary amines, the reactivity of isocyanates with primary amines to form polyureas is orders of magnitude faster than the reactivity of the isocyanates with primary alcohols to form polyurethanes [2,3]. Consequently, the diamine-diisocyanate polyurea synthesis readily occurs at room temperature and does not require the use of a catalyst [4,5]. The very fast kinetics of these reactions enable the development of industrial reaction injection molding (RIM) processing, which is of particularly high significance in the automotive industry [5,6].…”

“…Consequently, the diamine-diisocyanate polyurea synthesis readily occurs at room temperature and does not require the use of a catalyst [4,5]. The very fast kinetics of these reactions enable the development of industrial reaction injection molding (RIM) processing, which is of particularly high significance in the automotive industry [5,6]. Also well-known are the reactive spray-coating applications, which exhibit enhanced properties such as high ballistic impact resistance [6][7][8][9][10].…”