Preparation and properties of poly(urethane-imide)s derived from amine-blocked-polyurethane prepolymer and pyromellitic dianhydride

Preparation and characterization of PEG-modified polyurethane pressure-sensitive adhesives for transdermal drug delivery

“…Adhesive properties, particularly 180° peel strength and holding power, could be improved by the increase of PU crystallinity 9 . Crystallinity of PEG-PU-PSAs was highly affected by the ratio of PEG/PPG/PTMG.…”

“…The hard monomer is one that would give rise to a polymer with a high glasstransition temperature such as diisocyanates and the chain extender 8 . PU-PSAs with expected properties could be prepared by controlling the ratio of two monomers 9 . The application of traditional PU-PSAs for TDDS is limited for some reasons such as low moisture permeability, adhesive properties, and drug loading 10,11 .…”

Calix[4]arenes Used as a New Type of Chain Extender in the Preparation of Polyurethanes

“…(Fig. 1) 5,11,17,27-di(hydroxyethoxy)-26,28-dihydroxycalix [4]arene (CA [4]-OH) 1 [31] A mixture of CA [4] (calixarene/toluene, 2.96 g, 4.0 mmol), K 2 CO 3 (5.52 g, 40 mmol), and KI (9.0 g, 54.2 mmol) in dry acetonitrile (150 mL) was heated at reflux for 1 h under an argon atmosphere. 2-Chloroethanol (4 mL, 60.5 mmol) was added and the mixture was heated at reflux for another 72 h. After the solvent was distilled under reduced pressure, the residue was extracted with CHCl 3 ( [4]arene 3 [32] A mixture of CA [4] (calixarene/toluene, 5.0 g, 6.7 mmol), K 2 CO 3 (4.3 g, 31.2 mmol), chloroacetonitrile (2 mL, 31.5 mmol), and NaI (4.9 g, 32.7 mmol) in acetone (125 mL) was stirred and heated under reflux for 6 h. The suspension was cooled to room temperature and filtered.…”

“…[3] Incorporation of a silicon chain extender resulted in biostable PUs with low modulus and high elongation, [4] and the thermal stability of PU was significantly increased by the introduction of an imide component while the PU prepolymer reacted with pyromellitic dianhydride. [5] Calixarenes are known as molecular hosts and consist of an array of phenol and methylene groups alternately arranged within a macrocyclic ring, which can be easily modified. The introduction of suitably derivated calixarenes to a polymer backbone can be a substantial advancement for the practical application of the intrinsic receptor properties of the macrocyclic system in a solid support.…”

Preparation of Poly(p‐phenylenepyromelliteimide) Microspheres with Rugged Surfaces Using Crystallization During Isothermal Polymerization

“…In order to prepare the PPPI microspheres with rugged surface, crystallization of oligomers is desirable rather than liquid-liquid phase separation. It has been known that the polyimides are not formed via the formation of poly(amic acid) by reaction of either aromatic dianhydrides with aromatic diisocyanates [28][29][30][31] or of aromatic dithioanhydrides and aromatic diamines. [32][33][34][35][36] These reactions undergo without the formation of oligo(amic acid)s, and hence it is expected that the oligoimides is precipitated by crystallization.…”