Polyester Diol Research Articles

Preparation and properties study of waterborne polyurethane synthesized by mixing polyester diols and isocyanates

AbstractIn view of environmental protection requirements, it is an inevitable trend for waterborne coatings to replace traditional coatings. Waterborne polyurethane (WPU), a kind of typical resin used in coatings, has become a research hot topic of waterborne coatings because of its advantages, such as non‐polluting, safe and reliable, excellent properties, good compatibility, and easy modification. In this article, solvent‐free WPU is prepared by mixing 4,4′‐dicyclohexylmethane diisocyanate/ isophorone diisocyanate (HMDI/IPDI) and polycarbonate diol/ Polycaprolactone diol (PCDL/PCL). Through the comparison of the properties of the polymer, the best amount of raw materials was determined. Specifically, R = 1.35 (R is NCO/OH ratio), the content of dimethylolpropionic acid (DMPA) is 5.5%, the content of trimethylol propane (TMP) is 2.5%, the mole ratio of HMDI/IPDI is 2:1, the mole ratio of PCDL/PCL is 2:1, and the preeminent WPU shows the excellent thermal stability, the contact angle of 118.04°, the hardness is H. The chemical structures and rough surface morphologies of the WPU films were characterized by FT‐IR, TG, AFM, and SEM, respectively. Therefore, considering the film properties, and the low cost, simple, and green process, this research will offer the possibility of application of this free‐solvent WPU in industrial production and large‐scale application.

Sequence-Rearranged Cocrystalline Polymer Network with Shape Reconfigurability and Tunable Switching Temperature.

Switching temperature (Tsw) is a key parameter governing the service condition of shape memory polymers (SMPs). However, tuning Tsw of SMPs often requires sophisticated synthesis or intricate processing. Herein, we report a simple yet effective strategy to prepare the SMPs with tunable Tsw and good reconfigurability by using the cocrystalline polyesters as the reversible phase. The cocrystallizable copolyesters with rearranged sequences were prepared by the transesterification of mixed polyester diols and then photo-cross-linked to achieve the SMP networks. Cocrystallization of copolymer blocks endows the SMP networks tunable melting point and relatively high crystallinity, affording the network good shape fixing and recovery ability at body temperature. Besides, the dynamic nature of transesterification, that enables the network to have good shape reconfigurability, allows for the easy processing of SMPs with complicated shapes. The reconfigurable SMPs capable of actuating at the body temperature show great potential for use as biomedical devices.

Synthesis, characterization and properties of biomass and carbon dioxide derived polyurethane reactive hot-melt adhesives

AbstractPolyurethane reactive hot-melt adhesives (PURHs) are frequently employed in industries; however, there is still a need to develop more sustainable and versatile methodologies to expand the functions and fabrication of these important materials. Renewable feedstock can give PURHs with new functions, and reduce environmental impact. This study focuses on synthesizing PURHs using polyols derived from biomass (plants) and greenhouse gas (CO2) resources. These PURHs were characterized by multiple techniques, including solid-state 13C nuclear magnetic resonance (NMR), a dynamic mechanical analysis (DMA), single-lap adhesive joints strength of stainless steel, and hydrolytic ageing. The PURH film based on biomass poly(tetramethylene ether) glycol (bio-PTMEG) exhibited better water vapor permeability, tensile strength, and adhesive joints properties than PURHs based on cashew nutshell liquid (CNSL) polyester diol and poly(propylene carbonate)-poly(propylene glycol) (PPC-PPG) copolymer diol. The polyols blend of bio-PTMEG with biomass and CO2 based polycarbonate diols respectively provided PURHs films excellent hydrolysis resistance and adhesive strength on single-lap adhesively bonded stainless steel specimens. The work herein demonstrates that various renewable polyols can be employed in a sustainable fashion to optimize the structures and properties of PURHs for important applications.

Highly effective flame‐retarded polyester diol with synergistic effects for waterborne polyurethane application

ABSTRACTIn this article, a novel bi‐reactive flame retardant (FRD) was successfully synthesized for waterborne polyurethane (WPU). The chemical structures of FRD were characterized by Fourier‐transform infrared spectra and 1H and 31P nuclear magnetic resonance. Then, the FRD was incorporated into polyurethane backbone to prepare a series of flame‐retarded WPU (FRWPU). The flammability characteristics of FRWPU were measured by limited oxygen index (LOI), UL‐94, and cone calorimeter (CCT) tests. The FRPWU‐7 had a high LOI value of 30.5% with UL94 V‐0 rating. Moreover, the CCT values indicated that FRD induced the gaseous phase quenching effect of phosphorus‐containing free radicals derived from the decomposed phosphaphenanthrene group on the gas‐phase flame retardancy. Scanning electron micrographs and Raman spectra exhibited that FRD promoted the charring formation of phosphorus‐rich char layer with graphitized surface and honeycomb‐like intumescent structure in WPU matrix during burning. This study provides a new way to design a novel reactive P–P flame retardant consisted of the phosphaphenanthrene group and intumescent flame retardant for WPU application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48444.

Fabrication and Properties of a Bio-Based Biodegradable Thermoplastic Polyurethane Elastomer.

Using the melt polycondensation of five bio-based aliphatic monomers (succinic acid, sebacic acid, fumaric acid, 1,3-propanediol, and 1,4-butanediol), we first synthesized the more flexible and biodegradable polyester diols (BPD) with an average molecular weight of 3825. Then, the BPD was polymerized with excessive 4,4′-diphenylmethane diisocyanate (MDI). Finally, the molecular chain extender of 1,4-butanediol (BDO) was used to fabricate the biodegradable thermoplastic polyurethane elastomer (BTPU), comprising the soft segment of BPD and the hard segment polymerized by MDI and BDO. Atomic force microscope (AFM) images showed the two-phase structure of the BTPU. The tensile strength of the BTPU containing 60% BPD was about 30 MPa and elongation at break of the BTPU was over 800%. Notably, the BTPU had superior biodegradability in lipase solution and the biodegradation weight loss ratio of the BTPU containing 80% BPD reached 36.7% within 14 days in the lipase solution.

Blending Polymer Labile Elements at Differing Scales to Affect Degradation Profiles in Heart Valve Scaffolds.

After more than 22 years of research challenges and innovation, the heart valve tissue engineering paradigm still attracts attention as an approach to overcome limitations which exist with clinically utilized mechanical or bioprosthetic heart valves. Despite encouraging results, delayed translation can be attributed to limited knowledge on the concurrent mechanisms of biomaterial degradation in vivo, host inflammatory response, cell recruitment, and de novo tissue elaboration. This study aimed to reduce this gap by evaluating three alternative levels at which lability could be incorporated into candidate polyurethane materials electroprocessed into a valve scaffold. Specifically, polyester and polycarbonate labile soft segment diols were reacted into thermoplastic elastomeric polyurethane ureas that formed scaffolds where (1) a single polyurethane containing both of the two diols in the polymer backbone was synthesized and processed, (2) two polyurethanes were physically blended, one with exclusively polycarbonate and one with exclusively polyester diols, followed by processing of the blend, and (3) the two polyurethane types were concurrently processed to form individual fiber populations in a valve scaffold. The resulting valve scaffolds were characterized in terms of their mechanics before and after exposure to varying periods of pulsatile flow in an enzymatic (lipase) buffer solution. The results showed that valve scaffolds made from the first type of polymer and processing combination experienced more extensive degradation. This approach, although demonstrated with polyurethane scaffolds, can generally be translated to investigate biomaterial approaches where labile elements are introduced at different structural levels to alter degradation properties while largely preserving the overall chemical composition and initial mechanical behavior.

Emulsion stability and water tolerance of cationic waterborne polyurethane with different soft segment ratios between trifunctional polyether and bifunctional polyester

A series of cationic waterborne polyurethanes (WPU) was prepared using isophorone diisocyanate (IPDI) as the hard segment and polyester diol (PE2348), polyether triol (ZC330) or their mixture as the soft segment. The effects of the content of PE2348 and ZC330, crosslinking density on the particle size and its distribution, stability of WPU emulsion and the thermosstability, mechanical properties of WPU membrane were investigated. The results indicated that the increase of PE2348 in the mixed soft segment contributes to inhibiting the hydration, and the average particle size of the emulsion decreased because of the same cause. However, the stickiness of the corresponding film was increased and the elasticity deteriorated too. Structure uniform and suitable hydrophilicity of soft segment contributed to the stability, and higher crosslinking degree will contribute to the water-impregnation resistance of cationic waterborne polyurethanes membrane. Moderate hydrophilicity of polyurethane molecules and uniform distribution of hydrophilic structure are beneficial to uniform dispersion of polyurethane and better emulsion stability. If the miscibility between soft segments and hard segments and between the different soft segments is better, water resistance of the membrane will be improved significantly.

Replacement of petroleum-derived diols by sustainable biopolyols in one component polyurethane foams

This work reports on the development of eco-innovative and high performance one component polyurethane foams, originated from biopolyols, which were obtained from liquefaction of biomass, industry by-products, namely cork powder and eucalyptus bark. This effort consists of a cleaner production method to enable more sustainable materials and industry by-products valorisation, but also a reduction of the dependency on fossil oil derivatives. Low-value industrial cork powder and eucalyptus bark shreds were successfully liquefied into polyols, by a process based on acid-catalysed liquefaction, at atmospheric pressure, with conversion ratios up to 79%. The obtained biopolyols exhibited low acid values (1 mg KOH/g) and relatively high hydroxyl numbers (197–272 mg KOH/g) and were introduced into one component polyurethane formulations, fully replacing the petroleum-derived polyether and polyester diols in the formulation. The resultant rigid polyurethane foams exhibited a high output (16 g/s) and acceptable physical quality, assessed by optical and scanning electron microscopy. Their chemical structure, mechanical and thermal properties were evaluated through Fourier Transformed infrared spectroscopy, compression mechanical testing and thermogravimetric analysis, respectively.

Bio-polyols synthesized from bio-based 1,3-propanediol and applications on polyurethane reactive hot melt adhesives

Since polyol is one of the major components in the preparation of polyurethane adhesive, bio-based polyols applied in the adhesive can make them sustainable and environmentally friendly. Regarding of these properties, a series of new bio-based aliphatic poly(1,3-propylene dicarboxylate) diols were synthesized by bio-based 1,3-propanediol (bio-PDO) and aliphatic dicarboxylic acids with different chain lengths. These bio-based polyester diols combined with 100% renewably-sourced poly(trimethylene ether) glycol (PO3G) further reacted with 4,4′-diphenylmethane diisocyanate (MDI) to form polyurethane reactive hot melt adhesives (PURHMAs). The thermal and physical properties of sustainable PURHMAs were characterized by differential scanning calorimetry (DSC), X-Ray diffraction (XRD), dynamic mechanical thermal analyzer (DMA) and thermogravimetric analysis (TGA). Finally, the adhesion properties of PURHMAs on four different substrates were measured, in order to investigate the influence of carbon numbers in the repeating unit of bio-based polyester diols on the morphology and adhesive properties of PURHMAs. It was found that with increasing carbon numbers in the repeating unit, the compatibility between the bio-based polyester and PO3G chains in the PURHMAs was enhanced, the open time of PURHMAs became shorter, and the green strength was also improved. The adhesion performance of bio-based PURHMAs on different substrates was tested, and the results showed that all bio-based PURHMAs had good adhesion to PC, nylon 6 and stainless steel substrates. Furthermore, the bio-based PURHMAs also exhibited excellent bonding strength on PC substrates after the bonded PC/PC joints were aged under the condition of hot water or alkaline solution. All these results suggests that the bio-based PURHMAs can be used in automobile applications.

Synthesis, characterization, and mechanical performance of various functionalized carbon nanotubes‐polyurethanes nanocomposites

ABSTRACTNanocomposites of functionalized carbon nanotubes (CNTsf) used as a reinforcement agent, and a polyurethane (PU), as a polymeric matrix were synthesized via in situ polymerization. Carbon nanotubes (CNTs) were chemically functionalized using four different chemical treatments to obtain (1) oxidized CNTs (CNTsOH, COOH), (2) CNTs containing aliphatic amine groups (CNTset diam), (3) CNTs attached to an aromatic amine group (CNTs4AB), and (4) CNTs containing a combination of aromatic amine, hydroxyl, and carboxyl functional groups (CNTs4AB, OH, COOH). The nanocomposites (prepared using 0.25, 0.5 or 1.0 wt % CNTsf) were synthesized by two processes: (1) one‐step using a PU made from PCL‐diol (α‐ω‐telechelic polyester diol) obtained by biocatalysis from ε‐caprolactone (ε‐CL) and diethylene glycol (DEG) and 4,4′‐methylenebis (cyclohexyl isocyanate) (H12MDI) in stoichiometric amounts, (2) two‐step process (chain extended PU) using hexamethylene diamine (HMDA). Depending on the chemical route used to synthesized the nanocomposites, CNTsf form, in some cases, covalent bonds and hydrogen bonding with the soft and/or hard segments of the PU matrix. Also, the presence of CNTsf improves the thermal stability of the nanocomposites and some of their mechanical properties, compared to the pure PU properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47319.

Synthesis and properties of high-functionality hydroxyl-terminated polyurethane dispersions

High-functionality hydroxyl-terminated polyurethane aqueous dispersions (OH-PUDs) were synthesized with sulfonic polyester diol as hydrophilic chain extender, and alcohol-amine compounds as end-cappers. Two-component waterborne polyurethane (2K-WPU) films based on OH-PUDs were prepared and characterized by ultraviolet-visible spectrophotometer and surface contact angle measurement. The effects of synthesis process, molar ratio of NCO/OH, type and molecular weight of macro-diol, and the category of alcohol-amine capping agents on the properties of OH-PUDs and 2K-WPU films were investigated. OH-PUD obtained from “first dispersing then blocking PU prepolymer” preparation process displayed the best storage stability. The water-resistance of 2K-WPU film was greatly improved with increasing the average functionality of OH-PUDs, and then OH-PUDs displayed good comprehensive properties with PCL220 as the soft segment, trometamol (Tris) as the end-capper and with 1.5 of NCO/OH molar ratio. The 2K-WPU film prepared from OH-PUD-3 exhibited good water-resistance, good transparency and high hardness.

Impact of Polymerization Protocol on Structure-Property Relationships of Entirely Lipid-Derived Poly(ester urethane)s

The impact of polymerization protocol on phase structure and properties of entirely lipid-derived thermoplastic poly(ester urethane)s (TPEU)s was investigated. The TPEUs were synthesized from 1,7-heptamethylene diisocyanate, polyester diols and 1,9-nonanediol (ND) as chain extender. A two-stage polymerization method was used to prepare two TPEUs; one in which ND was added in the first stage of polymerization as part of the prepolymer and another in the second stage after the prepolymer was formed. Two very different morphologies exhibiting different degrees of phase separation were obtained, driven by the sequence of addition of the chain extender. The incorporation of the chain extender in the prepolymer resulted in a TPEU with a narrow hard segment distribution, enhanced urethane-urethane hydrogen bonding and higher molecular weight. The hydrogen bond density, degree of crystallinity, glass transition temperature and mechanical properties of the TPEUs were directly related to the degree of phase separation and hence polymerization protocol.

Synthesis and characterization of a novel biodegradable elastomer based on citric-acid-crosslinked polyesters

ABSTRACTIn this study, poly(monoethylene diglycol sebacate) with a low molecular weight was synthesized from the reaction of ethylene diglycol and sebacic acid. The melt condensation reaction of the prepared polyester diol with citric acid produced a bioelastomer material comprising a network of transparent and flexible polyether esters. This material was amorphous, with a glass transition temperature of lower than 0°C. Its mechanical properties (tensile strength, 1.92–4.61 MPa; elongation at break, 201.9–348.9%) and degradation performance could be tuned by changing the molar ratio of the reacting monomers and controlling the crosslink curing time of the pre-polymer. As a biological material, the as-synthesized elastomer showed good hydrophilicity, water-absorption capability, and dimensional stability.

The effect of multiwalled carbon nanotube and crosslinking degree on creep–recovery behavior of PET waste originated‐polyurethanes and their nanocomposites

The polyester diol obtained from the glycolysis of the recycled PET flakes was used to synthesize the polyurethanes of PU‐1, PU‐1.7, and PU‐2 that the numbers indicate the isocyanate to hydroxyl groups (NCO/OH) molar ratios. The nanocomposites of PUs with hydroxylated multiwalled carbon nanotube (MWCNT) (PUCNT‐1.7 and PUCNT‐2) were synthesized via in situ polymerization, while the PUCNT‐1 was not synthesized due to the steric hinderance effect of MWCNT. It was shown that the NCO/OH molar ratios and the added MWCNT govern the crosslink degree of the samples. Because, the good creep–recovery behavior of the under‐loaded polymers in long time applications has remarkable importance for polymer engineers, the creep–recovery behavior of PUs and their nanocomposites was studied by dynamic mechanical analysis (DMA). Nevertheless, there has been no report on the creep–recovery behavior of these PET originated polyurethanes. The well‐known models of Power law and Burgers (for fitting the creep experimental data), and Weibull model (for fitting the recovery experimental data) showed the good agreements with the empirical data. The creep strain of the samples was in the order PU‐1 > PUCNT‐1.7 > PU‐2 > PU‐1.7 > PUCNT‐2. It was found that the crosslink‐degree of the samples and also the opposing effects of MWCNT (the reinforcing and hindrance effects) are the important parameters that govern Young modulus, creep, and recovery of the samples. PU‐1.7 due to its higher crosslink‐degree showed the lower creep–recovery strain in comparison to PU‐2 and PU‐1. The lower creep–recovery strain of PUCNT‐2 as compared to other samples can be attributed to the dominant reinforcing effect of MWCNT in this sample, whereas the high creep–recovery strain of PUCNT‐1.7 was assigned to the dominant hindrance effect of MWCNT. POLYM. COMPOS., 39:E1013–E1024, 2018. © 2017 Society of Plastics Engineers

Comparison of AdipicVersusRenewable Azelaic Acid Polyester Polyols as Building Blocks in Soft Thermoplastic Polyurethanes

AbstractIn this study, novel polyester diols of 2000 molecular weight (MW) were synthesized by reacting azelaic acid (AZ) with 1,3‐propanediol (1,3‐PDO) and diethylene glycol (DEG) in the esterification reaction catalyzed with a small amount of butyltintris(2‐ethylhexanoate). As a reference, polyester polyols of 2000 MW were synthesized from adipic acid (AA) with 1,3‐PDO and DEG. The properties of polyester polyols were evaluated. The polyester polyol based on AZ and 1,3‐PDO is 100 % renewable polyol; 1,3‐PDO used in the syntheses is renewable product produced by fermentation process of sugar. Both 1,3‐PDO‐polyester polyols exhibited crystalline transition above room temperature, while DEG‐polyester polyols were liquid at room temperature. The polyester polyols were chain‐extended with 4,4′‐diphenylmethane diisocyanate (Mondur M) and 1,4‐butanediol (BDO) to form thermoplastic polyurethanes (TPU). TPU were evaluated for mechanical and water resistance properties, and their morphology were studied via differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and atomic force microscope (AFM). TPU based on azelate and adipate polyols were relatively soft elastomeric materials with high melting temperatures. AFM analyses of TPU indicated better phase separation in 1,3‐PDO polyester polyols with the highest phase separation observed in TPU based on 1,3‐PDO/azelaic acid polyols. Water resistance of TPU based on azelate polyols was improved as compared to TPU based on adipate polyols.

Artificial extracellular matrix for biomedical applications: biocompatible and biodegradable poly (tetramethylene ether) glycol/poly (ε-caprolactone diol)-based polyurethanes

The cells as a tissue component need to viscoelastic, biocompatible, biodegradable, and wettable extracellular matrix for their biological activity. In this study, in order to prepare biomedical polyurethane elastomers with good mechanical behavior and biodegradability, a series of novel polyester–polyether- based polyurethanes (PUs) were synthesized using a two-step bulk reaction by melting pre-polymer method, taking 1,4-Butanediol (BDO) as chain extender, hexamethylene diisocyanate as the hard segment, and poly (tetramethylene ether) glycol (PTMEG) and poly (ε-caprolactone diol) (PCL-Diol) as the soft segment without a catalyst. The soft to the hard segment ratio was kept constant in all samples. Polyurethane characteristics such as thermal and mechanical properties, wettability and water adsorption, biodegradability, and cellular behavior were changed by changing the ratio of polyether diol to polyester diol composition in the soft segment. Our present work provides a new procedure for the preparation of engineered polyurethanes in surface properties and biodegradability, which could be a good candidate for bone, cartilage, and skin tissue engineering.

Reactive processing of thermoplastic elastomers based on polyamide-6: preparation and characterization

A new class of thermoplastic polyamide elastomers was successfully synthesized by polyaddition reactions between amino-terminated polyamide-6 and different diisocyanate-terminated polyether diols or polyester diols in a Haake torque rheometer. The chemical structure, phase separation, static and dynamic mechanical properties, thermal stability and hydrophilicity of TPAEs were characterized by Fourier transform infrared spectroscopy, differential scanning calorimeter (DSC), tensile tests and dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and water contact angle test methods, in the order given. DSC results showed that these synthesized TPAEs exhibited two obvious endothermic peaks associated with melting transition of soft segments and hard segments. The mechanical results revealed that TPAEs possess outstanding mechanical properties with tensile strength of 22.2–35.9 MPa and the elongation-at-break of 360–467 %. TGA results showed TPAEs can be fabricated by traditional thermoplastic processing method without any decomposition once the processing temperature is below 300 °C. Furthermore, the TPAEs only dissolved in acetic acid and methanoic acid at room temperature, showing TPAEs can be applied to some harsh environment due to excellent organic solvent resistance. Especially, this friendly reactive processing can also be used to handle the environmental problems associated with volatile organic compound emission.

Preparation and characterization of nanocomposites made from chemoenzymatically prepared polyester urethanes and functionalized multiwalled carbon nanotubes

Multiwalled carbon nanotubes (MWNTs) were functionalized with four different functional groups and used as nanofillers to reinforce biodegradable polyurethanes (PU), in an effort to explore their effect on the thermal and mechanical properties of the obtained nanocomposites. The PU were synthesized via one step process, by the reaction between a αω‐telechelic polyester diol (obtained by biocatalysis from ε‐caprolactone and diethylene glycol), and hexamethylene diisocyanate. The MWNTs were synthesized via a chemical vapor deposition process using ethanol as a carbon source. Functionalization with (i) hydroxyl and carboxyl groups OH‐COOH; (ii) aliphatic amine: ethylene diamine; (iii) aromatic amine: 4‐amine benzoic acid (4AB); or (iv) aromatic amine and carboxyl acid: 4‐amine benzoic acid, hidroxyl, and carboxyl groups (4AB‐OH‐COOH) were achieved. Nanocomposites were obtained by adding functionalized CNTs during the polymerization reaction between αω‐telechelic diol and the isocyanate. Three different percentages of functionalized CNTs were tried: (a) 0.25; (b) 0.5; or (c) 1%wt. The structural, morphological, and mechanical features of MWNTs/PU nanocomposites were studied by FT‐IR, differential scanning calorimetry, field emission scanning electron microscopy, TGA, wide angle X‐ray diffraction, solid‐state NMR, and mechanical properties. A better interfacial adhesion was observed for nanocomposites containing 0.5% wt of filler, compared to the neat PU. POLYM. COMPOS., 39:E697–E709, 2018. © 2016 Society of Plastics Engineers

Imparting elastomeric properties to entirely lipid-derived thermoplastic poly(ester urethane)s: Molecular weight control

High molecular weight, thermoplastic poly(ester urethane) (TPEU) elastomers were synthesized from oleic-acid derived polyester diols (PED)s and 1,7 heptamethylene diisocyanate (HPMDI). Functional group stoichiometry and polymerization time were used to control molecular weight and optimize thermal and mechanical properties. A targeted range of PEDs with controlled molecular weights and consistent dispersity were obtained in high yields using an induced stoichiometric imbalance method. The PEDs were reacted with HPMDI with different NCO:OH ratios (1.1–2.1) and polymerization times (2–24 h) to obtain high molecular weight TPEUs. Solvent-resistant TPEUs, displaying polyethylene-like behavior were obtained and characterized by GPC, FTIR, DSC, XRD, TGA, DMA and tensile tests in order to reveal the structure-property relationships. Melting temperatures, tensile strength and maximum strain scaled with molecular weight approaching saturation values, demonstrating a plateau effect of molecular weight on physical properties. The entirely lipid-derived TPEUs exhibited thermal and mechanical properties comparable to commercial, petroleum-based analogues.

Synthesis and characterization of permanently antistatic polyurethanes containing ionic liquids

An in situ embed ionic liquid method is designed and employed in thermoplastic polyurethanes (PUs). Unlike the traditional physically incorporated antistatic polymers where conductive fillers do not firmly combined with the matrix. This permanently antistatic PUs are successfully synthesized by using a novel polyester diol bonded with ionic liquids (ILs), which are obtained by an esterification. The ILs and novel polyester polyol are successfully synthesized and subsequently characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectrum (1H NMR), respectively. The effects of ILs content, temperature, and relative humidity (RH) on the surface resistivity of PUs are studied by surface resistivity tests. It is found that the surface resistivity of PUs dramatically decreases with the increment of ILs and are insensitive to surrounding environment. The surface resistivity of PUs with 5.96 wt% ILs reaches 1010 Ω cm−2 order of magnitude. The crystalline properties, thermal decomposition behaviors and mechanical properties of synthesized PUs are investigated by X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and tensile test respectively. The crystallinity of PUs with ILs is lower than that of pure PUs. Moreover, we also investigate the effect of ILs on the surface morphology of the PUs. POLYM. ENG. SCI., 2016. © 2016 Society of Plastics Engineers