Study on siloxane‐modified polyurethane dispersions from various polydimethylsiloxanes

Abstract

In this work, various polydimethylsiloxanes (PDMS) are incorporated with isophorone diisocyanate (IPDI), 2,2-bis(hydroxymethyl)propionic acid (DMPA), and poly(tetramethylene oxide) (PTMO) by the prepolymer process to synthesize a series of siloxane-modified polyurethane dispersions (PUDs) with 35 wt % solid content, viscosities of 20-100 cps, and particle sizes of 40-130 nm. Hydrophobic PDMS was introduced into the PU chain either based on random distribution or through the block segment arrangement. We also establish the composition-property relationship of PDMS-PUD, which includes PDMS's type and molecular weight and PDMS-PUD film's contact angle and mechanical property. The tensile strength of PDMS-PUD film is decreased with increasing amount of PDMS. Scanning electron microscopy for chemical element analysis indicated that PDMS migrated to the surface much more easily in the block arrangement than in the random distribution. Also, some PDMS-PUD films show a peau-like surface, so their PUDs are considered promising to be used in processes for textiles. V V C 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3482-3490, 2005

Effect of different polyethers on surface and thermal properties of poly(urethane-siloxane) copolymers modified with side-chain siloxane

“…The largest R a = 0.844 lm and R z = 4.0 lm reveals unmodified sample T1. For the coatings containing siloxane both parameters are lower which may results from the migration of siloxane chains toward the film surface as described in [16]. This production of smoother surface may be additionally confirmed by the lowest R a and R z for S1S copolymer with the largest siloxane amount.…”

“…This kind of PU anionomers, which were cross-linked with N-methylmonoethanolamine, compared to main-chain siloxane PU films, showed larger advancing contact angles but lower gloss and poorer tensile strength at the same amount of PDMS and similar molecular mass [15]. Chen et al [16] compared the properties of PU-Si anionomers in which polydimethylsiloxane was introduced into the PU chain either based on random distribution or through the block segment arrangement. The contact angle of the PU-Si film increased rapidly and reached a maximum at a siloxane amount of about 7 %.…”

“…Owing to its structure, this siloxane was inbuilt as a pendant chain into main polyurethane backbone [14][15][16][17].…”

A facile dip-coating process for preparing highly durable superhydrophobic surface with multi-scale structures on paint films

“…PDMS has a very low surface energy with a water contact angle of 109° [39]. Its segments in the coating layer have high tendency to enrich on the surface to promote the hydrophobicity because of its incompatibility with the epoxy matrix [40,41]. The influence of the M2 coating on both of the apparent contact angle and the sliding angle has been studied, and the results were illustrated in Fig.…”

Modification of Thermoplastics with Reactive Silanes and Siloxanes

“…These disadvantages can be eliminated by using a different mixing composition of soft segments. Chen et al (2005) prepared the anionic WPUs from hydroxyl-terminated PDMS, poly(tetramethylene oxide) (PTMO) as the soft segments, IPDI as the hard segment, and 2,2-bis(hydroxymethyl)-propionic acid (DMPA) as the ionic centre. DMPA was used to form a water-dispersible urethane prepolymer.…”