Properties Of Polyurethane Acrylates Research Articles

UV‐curable polyurethane acrylate resin containing multiple active terminal groups for enhanced mechanical properties

ABSTRACTIn this article, aiming to develop the high performance ultraviolet (UV)‐curable resin used in the polymer matrix composite, a series of polyurethane acrylate (PUA) resins with the different numbers of allyl terminal groups were elaborately designed and synthesized, in which the contents of hard segments and soft segments were also adjusted simultaneously. The effects of allyl number on properties of PUA were systemically investigated. It was found that allyl number had the negligible effect on the processability as well as positive effect on thermal performances, and all PUA resins exhibited the low viscosity and rapid UV polymerization. Besides, with the change of allyl number in the range of 2–4, PUA resin casting with three allyls possessed the preferable mechanical properties such as 85.1 MPa tensile strength, 3.94 GPa tensile modulus, and 20.7 kJ m−2 impact strength. More importantly, the high strength and high modulus of the composite further demonstrated the wide potentials of the as‐prepared PUA resin as the ideal resin matrix candidate for the fiber reinforced polymer composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48147.

Influence of the Nature of Acrylates on the Reactivity, Structure, and Properties of Polyurethane Acrylates

Polyurethanes (PUs) are one of the most versatile classes of polymers, and their demand as high-performance industrial materials continues to grow. In this work, new polyurethane acrylates were prepared from diglycidyl ether bisphenol A (DGEBA), substituted acrylic acids, and 4,4′-diphenylmethane diisocyanate using a two-step polymerization methodology. The polymers were characterized by infrared spectroscopy, 1H NMR spectroscopy, gel permeation chromatography, thermogravimetry, and X-ray diffraction. The influence of the structure of the acrylic acid on the reactivity with DGEBA was investigated. Density functional theory and canonical structures supported the reactivity order of the substituted acrylic acids toward DGEBA in both the gas and solution phases. All of the polyurethane acrylates investigated were found to have a high thermal stability.

Characterization of waterborne polyurethane for ecofriendly functional floor plate

Three types of nonmetallic mineral particles (CaCO 3, TiO 2 and loess) were incorporated into waterborne polyurethane acrylate (PUA) to improve the surface properties of ecofriendly floor tiles. Several properties of PUA containing nonmetallic mineral materials were measured by Fourier transform infrared spectroscopy (FT-IR), a dynamic mechanical thermal analyzer (DMTA), swelling tests, and contact angle measurement. Upon decreasing the molecular weight between crosslinks (variation of molecular weight of the polyol), the modulus and glass transition temperature ( T g) of the PUA film increased because of the increase in crosslinking density. Resistance properties such as swelling and contact angle against water were enhanced with the addition of nonmetallic mineral particles because of the increase in the hydrophobic nature of the polymer matrix.

Characterization of waterborne polyurethane for ecofriendly functional floor plate

Three types of nonmetallic mineral particles (CaCO 3, TiO 2 and loess) were incorporated into waterborne polyurethane acrylate (PUA) to improve the surface properties of ecofriendly floor tiles. Several properties of PUA containing nonmetallic mineral materials were measured by Fourier transform infrared spectroscopy (FT-IR), a dynamic mechanical thermal analyzer (DMTA), swelling tests, and contact angle measurement. Upon decreasing the molecular weight between crosslinks (variation of molecular weight of the polyol), the modulus and glass transition temperature ( T g) of the PUA film increased because of the increase in crosslinking density. Resistance properties such as swelling and contact angle against water were enhanced with the addition of nonmetallic mineral particles because of the increase in the hydrophobic nature of the polymer matrix.

Influence of initiator on synthesis and properties of polyurethane-acrylate hybrid emulsion

The prepolymer polyurethanes (PUs) based on isophorone diisocyanate (IPDI), poly(propylene glycol) (PPG), 1,4-butanediol (BDO) and dimethylopropionic acid (DMPA) were synthesized at 75–80 °C for 7–8 hours, using dibutyltin dilauate (DBTDL) as catalyzer, and polyurethane-acrylate hybrid emulsion was prepared after methyl methacrylate (MMA) was polymerized, using potassium persulfate and azobisisobutyronitrile (AIBN) as initiator, respectively. The influences of these factors such as the kind of initiator, the feed method of initiator and the addition of initiator on properties of polyurethane-acrylate were studied. The FTIR and GPC of aqueous polyurethane were analyzed. The FTIR spectra show that the degree of microphase-separate between the soft segments and rigid segments is high. The analysis of molecular weights stated that molecular weights increased most significantly after amine was added. The experimental results reveal that the appearance of emulsion is excellent, the film is harder and the water absorption radio of the film is less when oil-solubility AIBN is used as initiator. The semi-continuous can increase the molecular weight of polymer and the optimum amount of the initiator was 3% for MMA.

Effect of the diisocyanate on the structure and properties of polyurethane acrylate prepolymers

In this study, we investigated the role of diisocyanate on the properties of polyurethane acrylate (PUA) prepolymers based on polypropylene oxide (Mn = 2000 g · mol−1). The diisocyanates studied were isophorone diisocyanate, 4-4′dicyclohexylmethane diisocyanate, and toluene diisocyanate (pure 2,4-TDI, pure 2,6-TDI, and a TDI mixture, TDItech). The molecular structure of the diisocyanate had a major role on the course of the polycondensation and, more precisely, on the sequence length distribution of the final prepolymer. Moreover, the structural organization of the prepolymer also strongly depended on the nature of the diisocyanate. Two types of behaviors were particularly emphasized. On the one hand, the PUA synthesized from 2,4-TDI displayed an enhanced intermixing between soft polyether segments and hard urethane groups, as revealed by the analysis of hydrogen bonding in Fourier transform infrared. Consecutively, the glass transition shifted to higher temperatures for these polymers. On the other hand, strong hard–hard inter-urethane associations were observed in 2,6-TDI-based prepolymers; these led to microphase segregation between polyether chains and urethane groups, as revealed by optical microscopy. This inhomogeneous structure was thought to be responsible for the unusual rheological behavior of these PUA prepolymers. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2750–2768, 2000