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

To investigate the position and amount of the CF 3 group affecting the coloration of polyimides (PIs), we prepared 2,2-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane (2) with four CF 3 groups with 2-chloro-5-nitrobenzotrifluoride and 2,2-bis(4-hydroxyphenol)hexafluoropropane. A series of soluble and lightcolored fluorinated PIs (5) were synthesized from 2 and various aromatic dianhydrides (3a-3f). 5a-5f had inherent viscosities ranging from 0.80 to 1.19 dL/g and were soluble in amide polar solvents and even in less polar solvents. The glass-transition temperatures of 5 were 221-265°C, and the 10% weight-loss temperatures were above 493°C. Their films had cutoff wavelengths between 343 and 390 nm, b* values (a yellowness index) ranging from 5 to 41, dielectric constants of 2.68 -3.01 (1 MHz), and moisture absorptions of 0.03-0.29 wt %. In a comparison of the PI series 6-8 based on 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]propane, and 2,2-bis[4-(4-aminophenoxy)phenyl]propane, we found that the CF 3 group close to the imide group was more effective in lowering the color; this means that CF 3 of 5, 7, and 8f was more effective than that of 6c. The color intensity of the four PI series was lowered in the following order: 5 Ͼ 7 Ͼ 6 Ͼ 8. The PI 5f, synthesized from diamine 2 and 4,4Ј-hexafluoroisopropylidenediphthalic anhydride, had six CF 3 groups in a repeated segment, so it exhibited the lightest color among the four series.

A series of new strictly alternating aromatic poly(ester‐imide)s having inherent viscosities of 0.20–0.98 dL/g was synthesized by the diphenylchlorophosphate (DPCP) activated direct polycondensation of the preformed imide ring‐containing diacid, 3,3‐bis[4‐(trimellitimidophenoxy)phenyl]phthalide (I), with various bisphenols in a medium consisting of pyridine and lithium chloride. The diimide–diacid I was prepared from the condensation of 3,3‐bis[4‐(4‐aminophenoxy)phenyl]phthalide and trimellitic anhydride. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents such as N‐methyl‐2‐pyrrolidone (NMP) and N,N‐dimethylacetamide (DMAc). Transparent and flexible films of these polymers could be cast from their DMAc solutions. The cast films had tensile strengths ranging 66–105 MPa, elongations at break from 7–10%, and initial moduli from 1.9–2.4 GPa. The glass‐transition temperatures of these polymers were recorded between 208–275 °C. All polymers showed no significant weight loss below 400 °C in the air or in nitrogen, and the decomposition temperatures at 10% weight loss all occurred above 460 °C. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1090–1099, 2000

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A dicarboxylic acid {1,1‐bis[4‐(4‐trimellitimidophenoxy)phenyl]‐1‐phenylethane (II)} bearing two performed imide rings was prepared from the condensation of 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐1‐phenylethane and trimellitic anhydride in a 1/2 molar ratio. A novel family of poly(amide‐imide)s with inherent viscosities of 0.83–1.51 dL/g was prepared by triphenyl phosphite‐activated polycondensation from the diimide‐diacid II with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrrolidinone (NMP), pyridine, and calcium chloride. Because the 1,1,1‐triphenylethane group of II was unsymmetrical, most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N‐dimethylacetamide. All the soluble poly(amide‐imide)s afforded tough, transparent, and flexible films, which had tensile strengths ranging from 88 to 102 MPa, elongations at break from 6 to 11%, and initial moduli from 2.23 to 2.71 GPa. The synthesized poly(amide‐imide)s possessed glass‐transition temperatures from 250 to 287 °C. The poly(amide‐imide)s exhibited excellent thermal stabilities and had 10% weight losses from 501 to 534 °C under a nitrogen atmosphere. A comparative study of some corresponding poly(amide‐imide)s is also presented. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 775–787, 2001