Comparison of the characteristics of polyurethane elastomers based on DMC- and traditional polyethers

Korotkova, N. P.; Mishchenko, A. A.; Antipova, E. A.; Lebedev, V. S.

doi:10.1134/s1995421213010097

Cited by 4 publications

(2 citation statements)

References 2 publications

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“…Polyether polyols are widely used as the soft component in the production of polyurethanes (PUs) as foams, for coatings, adhesives, sealants, and elastomers (CASE polymers). − Historically, polyether polyols were produced by ring-opening polymerization (ROP) of epoxidesmainly propylene oxide (PO) and ethylene oxide (EO)with an alcoholic or acid di- or multifunctional starter in combination with alkaline catalysts, like KOH. − Today, double metal cyanide (DMC) solids have become an effective alternative for the chain transfer PO polymerization, also using hydroxyl-containing-molecules as a starter, i.e., as chain transfer agents (Scheme ). ,− …”

Section: Introductionmentioning

confidence: 99%

DMC-Mediated Propoxylation in Semibatch with an External Loop: Insights into the Catalytic Action

Stahl,

Wietzer,

Luinstra

2023

Ind. Eng. Chem. Res.

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The importance of mixing in a semibatch propoxylation for controlling the distribution width of poly(propylene glycol) (PPG) products using double metal cyanide (DMC) catalysis is demonstrated. A loop comprising a static mixer with Kenics elements was incorporated into a reactor setup, enabling propylene oxide to be added to the circulating reaction mixture shortly before the mixer. The analysis shows that when “catch-up kinetics” is operative, i.e., at higher catalyst particle concentrations and low molecular masses, improved mixing results in a PPG with a lower PDI and a higher steady-state PO conversion. Propoxylation of PPG with higher molecular masses and fewer catalyst particles per volume leads to products with a higher PDI or even bimodal distributions irrespective of improved mixing due to an imbalance between diffusion of the chain ends and propoxylation rate.

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Section: Introductionmentioning

confidence: 99%

DMC-Mediated Propoxylation in Semibatch with an External Loop: Insights into the Catalytic Action

Stahl,

Wietzer,

Luinstra

2023

Ind. Eng. Chem. Res.

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“…The second method was the preparation of polyurethanes by ester exchange reaction of di-carbamates with diols. This method does not use solvents, and was a green synthetic route derived from green materials [ 20 , 21 , 22 ]. The dicarbamates are mainly synthesized from cyclic carbonate and dimethyl carbonate (DMC).…”

Section: Introductionmentioning

confidence: 99%

A Non-Isocyanate Route to Poly(Ether Urethane): Synthesis and Effect of Chemical Structures of Hard Segment

et al. 2022

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A series of non-isocyanate poly(ether urethane) (PEU) were prepared by an environmentally friendly route based on dimethyl carbonate, diols and a polyether. The effect of the chemical structure of polyurethane hard segments on the properties of this kind of PEU was systematically investigated in this work. Polyurethane hard segments with different structures were first prepared from hexamethylene di-carbamate (BHC) and different diols (butanediol, hexanediol, octanediol and decanediol). Subsequently, a series of non-isocyanate PEU were obtained by polycondensation of the polyurethane hard segments with the polyether soft segments (PTMG2000). The PEU were characterized by GPC, FT-IR, 1H NMR, DSC, WAXD, SAXS, AFM and tensile testing. The results show that the urea groups generated by the side reaction affect the degree of crystallization of hard segments by influencing the hydrogen bonding of the hard segments molecular chains. The degree of hard segment crystallization, in turn, affects the thermal and mechanical properties of the polymer. The urea group content is related to the carbon chain length of the diol used for the synthesis of hard segments. When butanediol is applied to synthesize hard segment, the hard segment of the resulting PEU is unable to crystallize. Therefore, the tensile strength and modulus of elasticity of butanediol-based PEU is lowest among three, though it possesses the highest urea group content. When longer octanediol or decanediol is applied to synthesize the hard segment, the hard segments in the resulting polyether-based polyurethane are crystallizable and the resulting PEU possesses higher tensile strength.

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Properties and application of rubber-based sealants

Syao

Malysheva

2014

Polym. Sci. Ser. D

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Comparison of the characteristics of polyurethane elastomers based on DMC- and traditional polyethers

Cited by 4 publications

References 2 publications

DMC-Mediated Propoxylation in Semibatch with an External Loop: Insights into the Catalytic Action

DMC-Mediated Propoxylation in Semibatch with an External Loop: Insights into the Catalytic Action

A Non-Isocyanate Route to Poly(Ether Urethane): Synthesis and Effect of Chemical Structures of Hard Segment

Properties and application of rubber-based sealants

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