Morphological features and flammability of MDI/HMDI-based segmented polyurethanes containing 3-chloro-1,2-propanediol in the main chain

Pielichowski, Krzysztof; Słotwińska, Dominika

doi:10.1016/s0141-3910(03)00016-8

Cited by 15 publications

(5 citation statements)

References 13 publications

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“…This method was developed independently by Ozawa 18 and Flynn and Wall. 19 Another isoconversional procedure, introduced by Friedman, 20 uses as its basis the following relationship: ln ͩ d␣ dt ͪ ϭ ln f͑␣͒ ϩ ln A Ϫ E RT (9) which makes it possible to find the activation energy value from the slope of the line (m ϭ ϪE/R) when ln(d␣/dt) is plotted against 1/T for isoconversional fractions.…”

Section: Resultsmentioning

confidence: 99%

Segmented MDI/HMDI‐based polyurethanes with lowered flammability

Pielichowski¹,

Słotwińska²,

Dziwiński

2004

J of Applied Polymer Sci

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A series of segmented polyurethanes (PUs) based on 4,4Ј-diphenylmethane diisocyanate and 1,6-hexamethylenediisocyanate; polyoxypropylenediol (POPD); and low-molecular chain extenders, 1,2-propanediol or 3-chloro-1,2-propanediol was obtained by solution polymerization and characterized by GPC and microscopic methods. Spherical aggregates with diameter of about 200 nm, arranged in a quasi-linear mode, were observed by SEM technique; further investigations by the TEM method revealed hard-segment domains of longitudinal shape, with length of about 5-10 nm, showing some features of the arrangement along a "director" axis. The process of thermal decomposition was monitored by thermogravimetric analysis in both dynamic and isothermal mode; to gain a deeper look into the mechanism of decomposition, kinetic analysis was performed. First, isoconversional methods showed a multistep decomposition route, as the value of (apparent) energy of activation changes from about 150 kJ/mol in the first step up to about 350 kJ/mol in the third step, which corresponds to the energy of dissociation of COC bonds and leads to a char (carbonaceous) residue. Further calculations by means of the linear regression method revealed that kinetic model functions describing the degradation process of PU that does not contain chlorine were Bna 3 An 3 Fn, whereby for chlorine-containing polyurethanes the CnB 3 An 3 An model was applied as best fit. Volatile products were investigated by pyrolysis-gas chromatography/mass spectrometry method at 770°C; the low molecular weight decomposition products, which were identified, indicate that the depolymerization process, yielding mainly diols and isocyanates through breakage of urethane bonds, prevailed during the thermal treatment under pyrolytic conditions. Finally, the mechanism of thermal degradation of modified polyurethanes with lowered flammability was proposed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3214 -3224, 2004

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Section: Resultsmentioning

confidence: 99%

Segmented MDI/HMDI‐based polyurethanes with lowered flammability

Pielichowski¹,

Słotwińska²,

Dziwiński

2004

J of Applied Polymer Sci

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“…14 The hard segments, generated from isocyanates and chain extenders, are dispersed in the soft phase and can self-assemble between chains to enhance mechanical properties. 15 Notably, the interchain interactions, such as polar aggregation by hard segments and physical crosslink by hydrogen bonds, also contribute to the primary driving force for microphase separation. Such microphase separation may be the key to improving the mechanical properties of TPU elastomers at room temperature while maintaining excellent lowtemperature resistance.…”

Section: Introductionmentioning

confidence: 99%

The reinforcing effect of cyclic binary secondary amine chain extenders on the cryogenic performance of thermoplastic polyurethane elastomers

Geng

Wang

et al. 2022

J of Applied Polymer Sci

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The poor cryogenic performance of thermoplastic polyurethanes (TPU) severely restricts their extensive application in low‐temperature fields as elastomers. Chain extenders are one of the adjustable items for TPUs to optimize cryogenic performance. In this contribution, three cyclic amine homologs of imidazoline, piperazine and 2‐methylpiperazine are selected as bi‐functional chain extenders. The corresponding TPU elastomers, TPU‐IM, TPU‐PP, and TPU‐2P with identical soft segments, are synthesized by the prepolymer method. All TPUs' structure, morphology and thermodynamic properties were investigated. The results showed that the cyclic amine structure embedded in TPU hard segment can effectively promote microphase separation through hydrogen‐bonded crosslink and polar aggregation on the molecular scale, achieving a glass transition temperature (Tg) as low as −103.9°C for resisting low temperatures. The mechanical properties also demonstrated a 23‐fold improvement compared to the control TPU‐BD. The elastomer TPU‐PP possessed the best all‐around performance with an ideal Tg of −98.4°C and tensile strength of 18.1 MPa. We believe that these TPUs will have potential applications in cryogenic engineering.

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“…Reactive flame retardants, beside the atoms of phosphorus and halogens, contain functional groups, which can react with the functional groups of polyol or isocyanate and directly take part in the formation of the structure of polyurethane. Because the use of reactive flame retardants in polyurethanes is more preferable, a whole range of new phosphorus-and halogen-containing reactive compounds have been synthesized in recent years [6][7][8][9][10]. The thermal stability and combustibility of the polyurethanes on their basis, as well as based on other compounds, have been considered in detail [11].…”

Section: Introductionmentioning

confidence: 99%

Properties of Polyurethanes Based on Tall Oil Fatty Acids Ester with Different Types of Flame Retardants

Yakushin

Stirna

Sevastyanova

et al. 2013

KEM

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To decrease the combustibility of polyurethanes based on tall oil fatty acids ester, additives of five different halogen- and phosphorus-containing flame retardants were used. The efficiency of the flame retardants was evaluated from the change in the thermal, mechanical and combustibility characteristics of the obtained polyurethanes. It has been found that the phosphorus-containing flame retardant Levagard 4090 N decreases the combustibility of polyurethane to the greatest extent.

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Morphological features and flammability of MDI/HMDI-based segmented polyurethanes containing 3-chloro-1,2-propanediol in the main chain

Cited by 15 publications

References 13 publications

Segmented MDI/HMDI‐based polyurethanes with lowered flammability

Segmented MDI/HMDI‐based polyurethanes with lowered flammability

The reinforcing effect of cyclic binary secondary amine chain extenders on the cryogenic performance of thermoplastic polyurethane elastomers

Properties of Polyurethanes Based on Tall Oil Fatty Acids Ester with Different Types of Flame Retardants

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