Poly Tetramethylene Glycol Research Articles

Influence of β-cyclodextrin on morphologies and chemical, thermal, and mechanical properties of non-chain extended polyurethane elastomers

A series of polyurethane elastomers (PUEs) were synthesized from an aromatic diisocyanate (4,4′-diphenylmethane diisocyanate (MDI)), a polyether polyol (polytetramethylene glycol; molecular weight: 1000 Da (PTMG1000)), and using β-cyclodextrin (β-CD) as the cross-linker. In this study, we investigated the effects of the addition of β-CD on the morphologies and chemical, thermal, and mechanical properties. The introduction of β-CD in the main chain of PUEs was verified using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and swelling test. The morphology was analyzed through SEM and confocal laser scanning microscopy (CLSM). The results show that the PUEs containing β-CD units exhibited an incompatible microstructure that was improved by the addition of β-CD. The tensile strength of PUEs decreased with the addition of β-CD; however, the elasticity was maintained for <5 % β-CD content. The dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) were used to prove the existence of a chemically cross-linked structure and evaluate the thermal stability of PUEs having different β-CD content.

Polyurethane gas separation membranes with ethereal bonds in the hard segments

Polyurethanes (PUs) and polyurethane-ureas (PUUs), with good mechanical stability and the possibility of tuning the gas transport properties are promising materials for selective gas separation membranes. Here, we synthesized various types of PUs and PUUs with polytetramethylene glycol (PTMG), isophorone diisocyanate (IPDI) and different ethereal chain extenders (1:3:2M ratio). FTIR and DSC results showed that the phase separation would vary in PUs and PUUs structures by changing the length and functionality of the chain extenders. More mixing was inferred for PUs and PUUs with high ethereal content. In contrast, phase separation was more likely with increases in the chain extender length. Pure (CO2, CH4, O2 and N2) and mixed gas (CO2:N2 (50:50vol%) and CO2:CH4 (50:50vol%)) permeation measurements correlated well with the phase separation in the polymer structure. The octanediamine-based PUU with the highest amount of phase separation showed the highest permeability (160 barrer for CO2 and CO2/N2 selectivity of 30). On the other hand, the 3,6-dioxa- 1,8-octanediol- based PU, despite having the same chain extender length as octanediamine-based PUU, presented the lowest phase separation and gas permeability (62 barrer for CO2 and CO2/N2 selectivity of 29).

Properties and paper sizing application of waterborne polyurethanemicroemulsions: Effects of extender, cross‐linker, and polyol

ABSTRACTA series of waterborne polyurethane (WPU) microemulsions were synthesized through self‐emulsification methodology, using toluene‐2,6‐diisocyanate, polytetramethylene glycol (PTMG), poly‐caprolactonediol (PCL), and dimethylol propionic acid (DMPA) as monomers; isophorone diamine (IPDA) as chain extender; and aziridine as cross‐linking agent. The resultant WPU microemulsions were utilized as surface‐sizing agents for cellulose fiber paper. The influences of IPDA content, PTMG/PCL molar ratio, and aziridine content on the physicochemical properties of the resultant emulsions and sized paper have been investigated in detail. The WPU microemulsion displayed better surface sizing properties when it was prepared under the following conditions: the IPDA content of 2.96%, PTMG/PCL molar ratio of 0:4, and aziridine content of 2.0 wt %. The relationships between the WPU structure and properties of WPU films and sized paper were clearly illustrated. The mechanical properties and water resistance of sized paper were not only depended on the interactions, chain entanglements, and cross‐linking density among the WPU chains, but also relied on the interactions among polymers and fibers, as well as the polarity and stiffness of surface sizing agent. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43211.

Preparation and characterization of biodegradable polyurethanes composites containing thermally treated attapulgite nanorods

In this study, polyurethane (PU) was synthesized using 4,4,-diphenylmethane diisocyanate as a hard segment, polytetramethylene glycol and polycaprolactone diol as soft segments, and 1,4-butanediol (1,4-BD) as a chain extender. Thermally treated attapulgite (TAT) was added to the PU matrix to prepare TAT/PU nanocomposites. The TEM, FT-IR, XRD and EDS were used to characterize the structure and morphology of the TAT/PU nanocomposites. The TEM results show that TAT maintains its rod-like structure in the PU matrix. The results showed that the addition of a small content of TAT resulted in no obvious changes in the Fourier transform infrared (FT-IR) spectra. XRD results showed that the main crystalline peak of TAT became more pronounced with increasing content of TAT, and EDS showed that the content of Si increased with increasing content of TAT in the TAT/PU nanocomposites. The thermal and mechanical properties were optimal at 2 wt% TAT. When TAT was added at 5 wt%, agglomeration occurred, resulting in a decrease in the thermal and mechanical properties of the TAT/PU nanocomposites. Contact angle and AFM results showed that the hydrophobicity and surface roughness increased with increasing content of TAT. SEM showed that the hydrolytic degradation was affected by the test temperature, test time, and the content of TAT. Moisture absorption tests showed that the moisture absorption of TAT/PU nanocomposites increased with increasing content of TAT and higher environmental humidity.

Preparation and Characterization of Biodegradable Polyurethane Composites Containing Attapulgite Nanorods

ABSTRACTIn this study, polyurethane (PU) is synthesized using 4,4,‐diphenylmethane diisocyanate as the hard segments and polytetramethylene glycol and polycaprolactone diol as the soft segments. In addition, attapulgite (AT)/PU nanocomposites are prepared by adding AT into PU matrix.The structure and morphology of AT/PU nanocomposites are examined using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), and energy dispersive X‐ray spectroscopy (EDS). The TEM results show that AT maintains its rod‐like structure in the PU matrix. The FT‐IR results show that there is no significant change in the FT‐IR spectrum after a small amount of AT is added into the PU matrix. The XRD results show that the main crystallization peaks of AT become more apparent with increasing AT content, and the EDS results show that the intensity of the Si peak also increases with increasing AT content. In addition, the mapping shows that AT nanorods are poorly dispersed when the AT content reaches 5 wt%. The thermal and mechanical properties of the AT/PU nanocomposite with an AT content of 2 wt% are optimal, and when the AT content surpasses 5 wt%, an aggregation phenomenon occurs, resulting in reductions in the thermal and mechanical properties of the AT/PU nanocomposite. The contact angle test and atomic force microscopy results show that the surface of the nanocomposite becomes more rough and hydrophobic with increasing AT content. The scanning electron microscopy observations of the hydrolytic degradation of the AT/PU nanocomposites show that their hydrolytic degradation was affected by the test temperature, test time, and AT content. The moisture absorption test shows that the moisture absorption of the AT/PU nanocomposite increases with increasing AT content and ambient humidity.

Synthesis and Properties of Polyurethane Elastomers with Trehalose Units

In recent years, sugar-derived polymer materials have been actively investigated. In research of polyurethane (PU), sugar has been used as a raw material because it has properties similar to polyol. However, the elastic property of the obtained PU is substantially lost. Hence, the introduction of a sugar unit to PU while maintaining the elastic property remains a challenge in polymer chemistry. Here, we report the synthesis of a polyurethane elastomer (PUE) with a trehalose unit using raw materials such as an aromatic diisocyanate (4,4’-diphenylmethane diisocyanate), polyols including a polyether polyol (polytetramethylene glycol), two polyester polyols (polycaprolactone and polycarbonate diol), and trehalose. Novel PUEs with trehalose units are synthesized by a one-shot method. Trehalose, which has non-reducing properties, is used as sugar. The use of trehalose, which has been scarcely applied to PUE, is essential to obtain the desired PUEs with sugar units.

Synthesis of a novel UV crosslinking waterborne siloxane–polyurethane

Abstract A novel UV crosslinking waterborne siloxane–polyurethane (UV-WPU) was synthesized using isophorone diisocyanate (IPDI), glycidyl azide polymer (GAP), polytetramethylene glycol (PTMG), dihydroxybutyl terminated polydimethylsiloxane (DHPDMS), dimethylol propionic acid (DMPA) as main materials. The structure of UV-WPU was verified using Fourier transform infrared spectroscopy (FTIR). Attenuated total reflectance (ATR) was used to study the UV crosslinking reaction kinetics of UV-WPU under UV irradiation. The properties of UV-WPU coatings by UV and thermal curing was comparatively analyzed by thermal gravimetric analysis (TGA), as well as gel fraction, water resistance and water contact measurements. The gel fraction and TGA analyses also confirmed the formation of crosslinking structure in the UV-WPU structure after UV curing process. UV-WPU cured by UV showed good thermal stability, surface properties and water resistance.

Preparation and Characterization of Thermoplastic Elastomer Based on Amino-terminated Polyamide-6 and Diisocyanate-terminated Polytetramethylene Glycol

ABSTRACTPolyamide thermoplastic elastomers are successfully synthesized by adding polycondensation of amino-terminated polyamide-6 (with a molecular weight of 1000 and 2000 g/mol) and diisocyanate-terminated polytetramethylene glycol (with molecular weight of 1500 and2500 g/mol) with dimethylacetamide as solvent at 140°C. The structures of oligomers and polyamide thermoplastic elastomers are characterized by Fourier transform infrared. The thermogravimetry analysis result shows that the product displays good thermostability. Differential scanning calorimetry curves of polyamide thermoplastic elastomers exhibit two melting temperatures indicating phase separation of polyamide thermoplastic elastomers. Besides, the polyamide thermoplastic elastomers display excellent mechanical properties of high tensile strength (33–61 MPa) and high elongation at break (384–1220%).

Study of the synthesis and properties of polyurethane containing pyridyl units for shape memory

In this study, 4,4′-diphenylmethane diisocyanate and polytetramethylene glycol were used to prepare a prepolymer, and 2,6-pyridinedimethanol (2,6-PDM) was then used as a chain extender to prepare a novel polyurethane (PDM/PUs). Gel permeation chromatography analysis shows that the molecular weight of PDM/PUs increases as the 2,6-PDM content increases. Fourier transform infrared spectroscopy analyses demonstrate that by increasing the 2,6-PDM content, PDM/PUs will form strong hydrogen bonds. The thermal analysis of PDM/PUs indicates that the initial decomposition temperature of PDM/PUs-03 is approximately 10 °C higher than that of PDM/PUs-01. Differential Scanning Calorimetry and Dynamic Mechanical Analysis analyses indicate that increases in the 2,6-PDM content produce significant enhancements in the glass transition temperature (T g) and the dynamic T g of PDM/PUs. Stress–strain tests indicate that 2,6-PDM can increase the maximum stress and Young’s modulus of PDM/PUs while reducing the elongation rate at break. The results of moisture absorption rate test indicate that when the 2,6-PDM content and ambient humidity increase, the water absorption rate of PDM/PUs increases. Moreover, PDM/PUs exhibits good shape recovery (>90 %).

Synthesis, Characterization, and Electrospinning of Calcium-Containing Polyurethane Urea

Calcium-containing segmented polyurethane urea was synthesized using a calcium salt of p-aminobenzoic acid, polytetramethylene glycol, and 4,4′-methylene bis(cyclohexyl isocyanate) and thereafter fabricated into three-dimensional scaffolds for the use in biomedical applications. Biocompatibility evaluation of the polymer showed that this newly developed metal-containing polyurethane urea demonstrated good cytocompatibility and hemocompatibility. The fabricating ability of the metal-containing polymer was studied by the electrospinning process. The effect of various parameters such as polymer concentration, applied voltage, and flow rate on the electrospinning process, morphology, and diameter of the resultant fibers was investigated. The findings indicate that increasing the concentration and flow rate of the solution increases the fiber diameter. It was also demonstrated that increasing the applied voltage decreases the fiber diameter. Mechanical property evaluation of the scaffolds showed that the strength of the scaffold depends on both the diameter and morphology of the fibers. As the fiber diameter increases from 1.6 to 3.02 μm, the tensile strength enhanced from 3 to 7 MPa.

Characterization and Gas Permeation Properties of Synthesized Polyurethane-Polydimethylsiloxane / Polyamide 12-b-Polytetramethylene Glycol Blend Membranes

Blend membranes of synthesized polyurethane (PU) based on toluene diisocyanate (TDI), polydimethylsiloxane (PDMS) and polytetramethylene glycol (PTMG) with polyamide 12-b- polytetramethylene glycol (PA12-b-PTMG) were prepared by a solution casting technique. The heterogeneous microstructures of the blend membranes (PU /PA12-b-PTMG) were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Gas transport properties were determined for O2, N2, CH4, and CO2 gases and the obtained permeabilities were correlated with polymer properties and morphology of the membranes. Comparison of the results with that of the pure PU membrane indicates that the blend membranes had higher permeability to CO2, but lower permeability to O2, N2 and CH4 gases, and, therefore, had higher values of CO2/N2 and CO2/CH4 ideal gas pair selectivities. The blend membrane with 20 % (wt) PA12-b-PTMG showed the highest CO2 permeability (≈105 Barrer) compared to the PU and other blend membranes. In the blend membranes with 5–20 % (wt) PA12-b-PTMG contents an enhancement of CO2/CH4 (≈10) and CO2/N 2 (≈52) selectivities was observed. The experimental permeabilities of the blend membranes were compared with the calculated permeabilities based on a modified additive logarithmic model.

Silica를 함유하는 Polyurethane dispersion 투습방수 Film의 제조

Silica-polyurethane hybrid breathable films were prepared and their breathabilities were assessed. Appropriately aggregated silica was prepared through sol-gel reaction of water glass and its particle size ranged 360∼500nm. The polyurethane dispersion was prepared by the reaction of isophorone diisocyanate(IPDI) as diisocyanate and polytetramethylene glycol(PTMG) and dimethylol propionic acid(DMPA) as polyol, particle size ranging 30∼120nm. The reaction between isocyanate and hydroxyl group to form urethane bonding was checked by the intensity of the stretch peak of isocyanate at 2270cm -1 in the FT-IR. The silica was incorporated into polyurethane dispersion and casted into film. It was shown that the incorporated silica(1∼5wt.%) increased water vapour permeability of the films by 30∼100%, and decreased the hydrostatic pressure by 10∼40%. From the results, it could be concluded that the appropriate hybridization of silica can increase the breathability of polyurethane dispersion film, while minimizing the loss of hydrostatic pressure.

Synthesis of blocking polyether silicone oil and silicone blocking waterborne polyurethane and application to cashmere knitted fabric finishing

Blocking polyether silicone oil is prepared through a reaction between amino-terminated polyether and epoxide-terminated polyether silicones. A fabric finishing agent made with cationic waterborne polyurethane modified by silicone oil is prepared by using polytetramethylene glycol as the soft segment, N-methyl diethanolamine as the hydrophilic unit, and tailor-made blocking polyether silicone oil as a chain extender for modification purposes. The finishing agent and the blocking polyether silicone oil are jointly used to treat cashmere knitted fabric. It is found that resistance to pilling of the treated cashmere knitted fabric is improved from a scale of 2–3 to 4 and its washing shrinkage rate is reduced from 11.2% to 3.3%. The treated cashmere knitted fabric has good hydrophilic ability, high water vapor and air permeabilities, and a soft handle. Moreover, the color of the fabric remains almost unchanged after finishing and the durability of the finishing properties is excellent.

Enhancement of the gas separation properties of polyurethane membranes by alumina nanoparticles

In this work, polyurethane (PU) nanocomposite membranes were prepared using different concentrations of alumina (Al2O3) nanoparticles (0, 2.5, 5, 10, 20, and 30wt%). The main objective of this work is to evaluate the permeability of CO2, CH4, O2, and N2 gases in the polyurethane hybrid membranes at various Al2O3 contents and with two different chain extenders. Polyurethane was synthesized by bulk two-step polymerization based on polytetramethylene glycol (PTMG) and hexamethylene diisocyanate (HMDI). 1,4-butanediol (BDO) and 2-methyl-1,3-propanediol (MPD) were used as chain extenders to complete the conversion of the prepolymers to the final polyurethanes. The prepared polyurethane–Al2O3 membranes were characterized using Fourier Attenuated Total Reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscope (SEM), wide angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC) analyses. The results show a reduction in the gas permeability, but a significant enhancement in the CO2/N2, CO2/CH4, and O2/N2 selectivities with alumina content. The separation performances of the membranes were compared with Robeson׳s upper bound limit. The new modified Higuchi model was applied to predict the permeability of polyurethane–alumina hybrid membranes.

Synthesis and Properties of Polyurethane Elastomers Containing Sucrose as a Cross-Linker

Polyaddition using isocyanate and polyol forms polyurethane elastomer (PUE). However, this method has rarely been applied to the construction of PUEs containing sucrose. Hence, the introduction of sucrose (disaccharide) as a cross-linker via polyaddition remains a challenging subject in polymer chemistry. Here, we report the synthesis of PUEs using an aromatic isocyanate (4,4’-diphenylmethane diisocyanate), polyols including a polyether polyol (polytetramethylene glycol) and two polyester polyols (polycaprolactone and polycarbonate diols), and sucrose as a crosslinker by a one-shot method. The PUEs containing sucrose were successfully produced. The use of sucrose was essential to obtain the desired PUEs containing sucrose units in the main chain.

Intrinsically radiopaque polyurethanes with chain extender 4,4'-isopropylidenebis [2-(2,6-diiodophenoxy)ethanol] for biomedical applications.

Radiopaque polyurethanes are used for medical applications as it allows post-operative assessment of the biomaterial devices using X-ray. Inherently, radiopaque polyurethanes based on polytetramethylene glycol (PTMG), polypropylene glycol, 4,4'-methylenebis(phenyl isocyanate), and a new iodinated chain extender 4,4'-isopropylidenebis[2-(2,6-diiodophenoxy)ethanol] with flexible spacers were synthesized and characterized. The iodinated polyurethanes were clear, optically transparent, and had high molecular weights. The polyurethanes also possessed excellent radiopacity and high thermal stability. The biocompatibility of the most promising iodinated polyurethane was evaluated both in vitro (cytotoxicity evaluation by direct contact and MTT assay, using L929 mouse fibroblast cells) and in vivo (toxicology studies in rabbits and subcutaneous implantation in rats). The material was nontoxic and well tolerated by the animals. Thus, these radiopaque and transparent polyurethanes are expected to have potential for various biomedical applications.

Polyester monomers lack ability to bind and activate both androgenic and estrogenic receptors as determined by In Vitro and In Silico methods

The paper presents results from the screening of seven monomers used by Eastman Chemical to make various polymers. Ethylene glycol, diethylene glycol, polytetramethylene glycol, isophthalic acid, monosodium-5-sulfoisophthalic acid, 1,4-cyclohexanedicarboxylic acid, and dimethylcyclohexanedicarboxylate were screened for potential androgenicity or estrogenicity. The following studies were conducted: QSAR for binding to the AR and ER, in vitro Androgen Receptor Binding Assay, in vitro Estrogen Receptor Binding Assays (alpha and beta isoforms), in vitro Androgen Receptor Transactivation Assay in human cells, and in vitro Estrogen Receptor Transactivation Assay in human cells. None of the QSAR models predicted that any of the monomers possessed appreciable binding affinity for either AR or ER. Binding assays showed no evidence of interaction with either the AR or the alpha or beta ER receptors. Similarly, the AR and ER transactivation assays were negative. Moreover, six of the seven monomers have been subjected to 13-week and developmental toxicity studies in rats with no androgen- or estrogen-related effects being noted. Given the negative results of the in vitro screening assays (except PMG which demonstrated cytotoxicity) as well as available repeated dose and developmental and reproductive studies, the data suggest that none of the monomers tested exhibit androgenic or estrogenic hazards.

방향족 구조가 포함된 열가소성 탄성체 Poly(ether-b-amide)의 합성 및 특성

방향족 구조를 포함하고 분자량이 조절된 polyamide(PA) 올리고머를 4-aminobenzoic acid와 12-aminododecanoic acid의 축합반응으로 합성하였다. 이 올리고머를 여러 분자량의 polytetramethylene glycol(PTMG)과 축합하여 PA를 hard segment로 하고 PTMG를 soft segment로 하는 열가소성 탄성체로서 poly(ether-b-amide)(PEBA)를 제조하였다. 합성된 PEBA의 구조는 FTIR과 <TEX>$^1H$</TEX> NMR로 확인하였으며 DSC와 UTM을 사용하여 hard segment의 구조변화에 따른 열적특성과 기계적 성질의 변화를 비교해 본 결과 방향족 구조를 30%까지 포함할 때 결정성의 변화 없이 PEBA들의 용융온도는 높아졌고 초기 modulus와 strength는 더 크게 나타났다. Polyamide (PA) oligomers, which are the hard segment of poly(ether-block-amide) (PEBA), presenting thermoplastic and high performance elastomeric properties were prepared by polycondensation between 4-aminobenzoic acid and 12-aminododecanoic acid. Subsequently PEBAs were obtained by addition polymerization of the PA oligomers and various molecular weights of poly(tetramethylene glycol) (PTMG). The structure of the final PEBA was identified by using FTIR and <TEX>$^1H$</TEX> NMR and the thermal properties depending on changes in the structure of hard segment were collected by using DSC and UTM analysis. As the results, the melt temperature (<TEX>$T_m$</TEX>), the initial modulus, and the maximum strength of PEBAs increased with an increase in aromatic moiety up to 30% without reducing crystallinity.

폴리우레탄 코팅제에 있어서 Hard Segment와 Soft Segment의 조성 및 함량변화가 내마모성에 미치는 영향

Abstract : Weatherstrip coatings of urethane and silicon type which are fit to EPDM and thermoplastic materials are used in sealing systems for automotive applications for noise reduction and high slip characteristics for external applications, respectively. Polyurethane binder was successfully synthesized from poly(butyladiphate)diol (PBAD), poly(tetramethylene)glycol (PTMG) and isocyanate as starting materials. Then, polyurethane coating agents were prepared by using various additives. To investigate effects of segment types on the abrasion resistance of polyurethane coating agents, thin films based on polyurethane coating materials were fabricated. With increasing the amount of hard segment in the coating agent, abrasion resistance, modulus and tensile strength of the coating films were improved, but the elongation of the coating films was decreased. Key words : Polyurethane(폴리우레탄), Coating agent(코팅제), Abrasion resistance(내마모성), Anti-vibration rubber (방진고무), Weatherstrip(웨더스트립), Binder(바인더)

Study of nanostructure characterizations and gas separation properties of poly(urethane–urea)s membranes by molecular dynamics simulation

Molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) have been employed for understanding the effect of urethane and urea contents on gas separation properties of poly(urethane–urea)s (PUUs) membranes. Five membranes considered in this study are based on polytetramethylene-glycol (PTMG), isophorone diisocyanate (IPDI), and designed ratios of 1,4-butanediamine (BDA) to 1,4-butanediol (BDO) as chain extenders. The glass transition temperature (Tg), density, fractional free volume (FFV), X-ray diffraction (XRD) pattern and radial distribution function (RDF) were calculated to examine the nanostructure characterizations of the membranes. The permeations of five gas molecules (O2, N2, CO2, CH4, and H2S) through the membranes were investigated. It was found that d-spacing, fractional free volume and phase separation of hard and soft segments increase with increasing urea contents in the membranes. The results indicated that the permeability of the membranes increases with increasing urea linkage in the polymer configuration.