Convenient post-curing reactions for aqueous-based polyurethane anionomers

Self Cite

ABSTRACT:The carboxyl group containing aqueous-based polyurethane (PU) dispersions were prepared from isophorone diisocyanate, poly(propylene glycol)-1000, and 2,2-dimethylol propanic acid via a PU prepolymer process. The amino content of this amino-terminated aqueous-based PU system was determined by a styrene oxide titration method. Glycidyl methacrylate (GMA) copolymer emulsions were prepared by an emulsion polymerization of GMA and other alkyl acrylates. The curing behavior of the GMA copolymer was demonstrated by a model reaction of the GMA copolymer with ethylenediamine. In the same token, the reaction took place between the PU amino groups and the GMA copolymer epoxides at ambient temperature and resulted in the formation of a hybridized homogeneous copolymer. This hybridized copolymer also consisted of carboxylic acid on the PU fraction after drying. Carboxylic acids of the copolymer were exchanged with calcium ion and this ionic coordination resulted in a calcium ion-crosslinked copolymer. The physical and mechanical properties and the thermal behaviors of the hybridized copolymers were evaluated.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Hybridization of aqueous-based polyurethane with glycidyl methacrylate copolymer

Chen¹,

Chen²

1999

Self Cite

“…Besides, these ionic groups provided surface charges and stabilized aqueous PU dispersions; the carboxylic ions are also the curing sites that reacted with a multi-aziridinyl compound for the aqueous-based PU curing system. 2,4 A compound with high phosphorus and nitrogen content could produce a synergistic effect on the flame retardation for polymeric materials, [7][8][9] due to the formation of a condensed phase and a nonflammable gas phase, which are formed, respectively, by their phosphorus and nitrogen compositions and which, in turn, promote the char formation. 16 A series of aziridinyl and phosphorus-containing compounds were synthesized from the substitution reactions of POCl 3 with phenol or ethylene glycol and aziridine, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…The postcuring reaction is the method used to improve on these shortcomings. [1][2][3][4][5][6] The aqueous-based PU dispersions were prepared from isophorone diisocyanate, polypropylene glycol-1000, and dimethylolpropanic acid (DMPA). The carboxylic group on the PU molecule is an ionic center for a self-emulsified aqueous-based PU system and it is the group that is reactive toward the compound containing the aziridinyl group.…”

Section: Introductionmentioning

confidence: 99%

“…Multi-aziridinyl compound serves as a PU latent curing agent and its curing reaction took place either on drying or when its pH value dropped below 6.0. 2,4 A phosphorus-containing compound could be a flame retardant for polymeric material. [7][8][9][10][11][12][13][14][15] Furthermore, when a compound contains both phosphorus and nitrogen, it performs a synergistic flame-inhibition function.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Introduction of covalently bonded phosphorus into aqueous-based polyurethane system via postcuring reaction

Wang

Chen

1999

Self Cite

Anionic aqueous-based polyurethane (PU) dispersions were derived from a water dispersion process of carboxylic groups containing PU prepolymers together with a neutralization and a chain extension. These PU prepolymers were prepared from a conventional polyaddition of isophorone diisocyanate, polypropylene glycol-1000, and dimethylolpropanic acid. A covalently bonded phosphorus was introduced into PU by a phosporus-containing curing agent. A series of phosphorus and multi-aziridinyl groups containing curing agents were synthesized for this purpose. Each of them served in a dual-function capacity as a postcuring agent for the anionic aqueous-based PU system. The resulting postcured PU exhibited improvements in its mechanical, physical, and thermal properties; furthermore, postcured PU synergistic flame inhibition was also observed due to the presence of nitrogen and phosphorus content in the process.

Flame retardation improvement of aqueous-based polyurethane with aziridinyl phosphazene curing system

Huang

Yeh

Chen

et al. 2000

Self Cite

Aziridinyl phosphazene (NPAZ) was introduced to aqueous‐based polyurethane (PU) as a flame retardant and a postcuring agent, mainly because of the presence of phosphorus compositions, as well as the reactive aziridinyl groups on NPAZ. This dual‐function NPAZ was prepared from the substitution reaction of hexachlorocyclotriphosphazene with aziridine. Aqueous‐based PU was treated with NPAZ and its curing reaction took place upon drying. The performance properties of this NPAZ cured PU (NPAZ‐PU) were improved and better than those of the original PU. The phosphorus composition from NPAZ was evenly distributed on this NPAZ‐PU film, which was identified by the phosphorus mapping on the energy dispersion spectrum. The physical and mechanical properties of NPAZ‐PU were evaluated by the measurements of the gel content, water uptake, ethanol swelling, and tensile stress. The thermal properties of NPAZ‐PU were investigated by thermogravimetric analysis (TGA), TG analyzer‐interfaced FTIR, and dynamic mechanical thermal analysis. Furthermore, its combustion behaviors were demonstrated with the data of a cone calorimeter measurement. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 662–673, 2001