Synthesis of poly(urethane-imide) using aromatic secondary amine-blocked polyurethane prepolymer

Gnanarajan, T. Philip; Nasar, A. Sultan; Iyer, N. Padmanabha; Radhakrishnan, Ganga

doi:10.1002/1099-0518(20001115)38:22<4032::aid-pola30>3.0.co;2-r

Cited by 58 publications

(15 citation statements)

References 16 publications

(8 reference statements)

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“…The de-blocking reaction of Nmethylaniline from polyurethane prepolymer occurs at 120 8C. [23] The isocyanate groups that were generated by the removal of blocking agent, N-methylaniline, react with phenolic groups in linear poly(urethane-imide)s, giving crosslinked polymers.…”

Section: Synthesismentioning

confidence: 99%

“…Recently our group has studied aromatic secondary amines as blocking agent for isocyanates [22] and found that particularly N-methylaniline was superior to phenol, a popular blocking agent for isocyanate, in the preparation of poly(urethane-imide) copolymer using blocked polyurethane prepolymer. [23] Reports on the reaction of aliphatic anhydrides with isocyanates are very scarce. In this article we report the preparation of crosslinked poly(urethane-imide)s via a simple reaction between N-methylaniline blocked polyurethane prepolymer and aliphatic heterocyclic dianhydrides.…”

Section: Introductionmentioning

confidence: 99%

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Mechanical and Thermal Properties of Networks Prepared from Reactive Poly(urethane-imide)s and Blocked Polyurethane Prepolymer

Iyer¹,

Gnanarajan²,

Radhakrishnan³

2002

Macromol. Chem. Phys.

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Section: Synthesismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mechanical and Thermal Properties of Networks Prepared from Reactive Poly(urethane-imide)s and Blocked Polyurethane Prepolymer

Iyer¹,

Gnanarajan²,

Radhakrishnan³

2002

Macromol. Chem. Phys.

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“…They are (a) by reacting isocyanate terminated PU prepolymer with dianhydride. [25,26] (b) reacting isocyanate terminated PU with diols or diacids containing imide groups, [27] (c) reacting blocked PU prepolymer with dianhydride [28] and (d) reacting blocked PU prepolymer with poly(amic acid) (PAA). [19] In this work, we have prepared PUI according to method (d).…”

Section: Introductionmentioning

confidence: 99%

Preparation of Nanoporous Polyimide Films from Poly(urethane‐imide) by Thermal Treatment

Krishnan

Cheng

et al. 2003

Macro Materials & Eng

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Nanoporous polyimide films were prepared in two steps. The first step is the preparation of poly(urethane‐imide) films by casting blend solutions containing various weight percentages of poly(amic acid) and phenol blocked polyurethane prepolymer (from 1,6‐hexamethylene diisocyanate and poly(ethylene glycol)). Three poly(amic acid)s were obtained from biphenyltetracarboxylic dianhydride (or) 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride with 1,4‐phenylenediamine (or) 2,5‐dimethyl‐1,4‐phenylenediamine. Poly(urethane‐imide) films were characterized by density and surface energy measurements, AFM, DSC, TMA, mechanical properties and TGA. In the second step, these films were thermally treated above 300 °C to give nanoporous polyimide films. During thermal treatment, less thermally stable urethane domains decomposed, leaving porous polyimide films. The presence of pores was confirmed by scanning electron microscopy (SEM). The dielectric constant of the polyimide film was found to decrease with increasing amounts of urethane content.A nanoporous polyimide film.magnified imageA nanoporous polyimide film.

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“…Polyurethanes are a very large and varied family of incredibly versatile and useful engineering materials due to their versatile properties, which stem not only from their excellent properties, but also because of their easily tailor-made nature (1)(2)(3)(4). Polyurethanes can be tailored by chemistry and processing to produce a wide range of products namely elastomers, coatings, foams, textiles, membranes, sealants, adhesives etc.…”

Section: Introductionmentioning

confidence: 99%

Preparation and Properties of Non-ionic Polyurethane Crosslinkers from 2-Ethoxyethanol/ϵ-caprolactam-Blocked Diisocyanate

Shen

Liang

2012

Journal of Macromolecular Science, Part A

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A series of novel water-based non-ionic blocked polyurethane crosslinker (n-BPUC) dispersions have been synthesized by the reaction of toluene 2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), polyethylene glycol (PEG), 1,1,1-trimethylolpropane (TMP), 2-Ethoxyethanol (2-Et) and ε-caprolactam (CL). The physical properties of prepared n-BPUC dispersions such as viscosity, pH, and storage stability are measured and compared. The chemical structure of the prepared n-BPUC dispersions is confirmed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). Deblocking temperatures of the n-BPUC dispersions are analyzed by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) techniques. The thermal analysis reveals that deblocking temperature obtained by DSC and TGA techniques is compared and found to be in the order DSC < TGA. Based on DSC and TGA data, it is shown that deblocking of n-BPUC dispersions based on 2-Et start at lower temperatures compared to that of the ones based on CL. The TDI-based n-BPUCs show higher reactivity than the ones based on IPDI. Hydroxyl-terminated polyurethane (HPU) is introduced to estimate the crosslinking effect of the prepared n-BPUCs. The better tensile properties and water resistance of n-BPUC modified HPU films compared to pure HPU film demonstrate the good crosslinking effect of the prepared n-BPUCs.

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Synthesis of poly(urethane-imide) using aromatic secondary amine-blocked polyurethane prepolymer

Cited by 58 publications

References 16 publications

Mechanical and Thermal Properties of Networks Prepared from Reactive Poly(urethane-imide)s and Blocked Polyurethane Prepolymer

Mechanical and Thermal Properties of Networks Prepared from Reactive Poly(urethane-imide)s and Blocked Polyurethane Prepolymer

Preparation of Nanoporous Polyimide Films from Poly(urethane‐imide) by Thermal Treatment

Preparation and Properties of Non-ionic Polyurethane Crosslinkers from 2-Ethoxyethanol/ϵ-caprolactam-Blocked Diisocyanate

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