Polyether-polyester and HMDI Based Polyurethanes: Effect of PLLA Content on Structure and Property

Shi, Lei; Zhang, Ruoyu; Ying, Wu-Bin; Hu, Han; Wang, Yubin; Guo, Yu; Wang, Wen-Qin; Tang, Zilong; Zhu, Jin

doi:10.1007/s10118-019-2283-3

Cited by 25 publications

(21 citation statements)

References 31 publications

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“…For that, PLLA existing in the forms of crystalline and amorphous phase in blends was selected as a polymeric ller. The chemical and physical features of PLLA play an important role in the ultimate performance prole of the multiphase blends: (1) the crystalline domains of PLLA with high modulus and their orientation behaviors under applied force can reinforce the blends with increased tensile strength and toughness; [37][38][39] (2) the amorphous parts facilitate the formation of hydrogen bonds with polyurethane and the ordering of the amorphous phase is responsive and tunable under tension, which are effective in toughening polyurethane. 37,40 Translucent polymer blends PU/PLLAs with varied ratios of PLLA from 0 to 20 wt% were prepared via the solution casting method (details of the preparation are described in ESI, Table S1 †).…”

Section: Resultsmentioning

confidence: 99%

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Empowering self-reporting polymer blends with orthogonal optical properties responsive in a broader force range

Mou-cheng

Guo

et al. 2021

Chem. Sci.

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Section: Resultsmentioning

confidence: 99%

“…50 Besides, strain-induced orientation is a well-known characteristic of PLLA reinforced elastomers. 37,38,40 The two factors are kinetically controllable, which is favored under low strain rate, but negligible for ameliorating mechanical properties as well as for bond scission events at high rates. 51 As shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Empowering self-reporting polymer blends with orthogonal optical properties responsive in a broader force range

Mou-cheng

Guo

et al. 2021

Chem. Sci.

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“…The crystallization behavior of PLLA-PUs is summarized in Figure S2 and Table S2. 32 Furthermore, Fourier transform infrared (FTIR) information is provided in Figure S3.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Poly(l-lactic acid) Microdomain as a Nanopolarization Rotator in a Flexible, Elastic, and Transparent Polyurethane

Wang

Ying

et al. 2020

ACS Appl. Polym. Mater.

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Chiral molecules have the ability to rotate the polarization plane of polarized light. Polymers that own a chiral segment are called optically active polymers, and a rigid backbone is usually required to maintain the chiral conformation, which also restricts their application mostly in the solution state. Polylactide acid is one of the most important biobased and biodegradable polymers, and its repeating unit could have left-handed and right-handed conformations. However, the utilization of its optical activity is mainly to improve its mechanical performance by forming a stereocomplex. In this work, we incorporate the poly(l-lactic acid) (PLLA) diol in the soft segment of a polyurethane elastomer with high transparency and good recoverability. During the tensile process of in situ small-angle polarized light scattering, we find that the polarization plane of the incident light will be tuned periodically. The brightening process under the horizontal–vertical (Hv) mode always corresponds to the darkening procedure under the vertical–vertical (Vv) mode and vice versa. As the strain increases, the period where the scattering pattern changes from bright to dark also increases. Small-angle X-ray scattering/wide-angle X-ray scattering results exclude any periodic structural evolution in a length scale of 0.1–100 nm, and we conclude that the chiral PLLA segment induced such a polarization rotation phenomenon. The decrease of effective thickness of PLLA domains along the light path caused the periodic change in the polarization degree. Such a polyurethane elastomer can be used as a component in stretchable electronics and is very useful in tumor imaging and defect detection.

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“…It is due to a higher energy bonding of urethane-ester in comparison to urethane-ether (lower compatibility between soft and hard segments) which means that lower C O groups interact with soft segments, maintaining many C O groups in the free state. [23] Moreover, the increment of ether groups in PU, leads to both a decrease and an increase in the H-bonded C O in the ordered and disordered conformation, respectively. These are the result of higher tendency of ester-ester hydrogen bonds to be generated in comparison to the ether-ether hydrogen bonds, which leads to the hard segments aggregation, and forming hard domains.…”

Section: Ftir Spectra Of Bulk Pumentioning

confidence: 99%

Shape memory thin films of polyurethane: Synthesis, characterization, and recovery behavior

Dehaghani

Kaffashi

2020

J of Applied Polymer Sci

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Polyurethane thin films with inherent two phase segregated characters are exceptional candidates for the development of shape memory materials. However, controlling the phase behavior of such complex structures for decoding their recovery behavior still experiences its early stage of development. In this work, polyurethane thin films were synthesized based on two polyols, ester‐based polyols (ESP), and ether‐based polyols (ETP) together with diphenyl diisocyanate (MDI). The effects of ingredient ratio of PETP (ether‐based prepolymer)/PESP (ester‐based prepolymer) on the chemical structure and final properties of polyurethanes were studied by the Fourier‐transformed infrared spectroscopy (FTIR), the differential scanning calorimetry (DSC), the scanning electron microscopy (SEM), the dynamic mechanical thermal analysis (DMTA), a tensiometer, and the atomic force microscopy (AFM). The shape memory behaviors were explored by the thermomechanical cycles applied by a DMTA device in the controlled force mode. The PU films showed various properties compared with the bulk PU since they formed spherulitic textures with different structures. All the PU films except PU‐0 showed high shape recovery ca. 90% in the first cycle with a large glassy storage modulus in the range of 2,800–4,040MPa, and a recovery ratio enhanced by increasing the number of cycle to a maximum of 95%.

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Polyether-polyester and HMDI Based Polyurethanes: Effect of PLLA Content on Structure and Property

Cited by 25 publications

References 31 publications

Empowering self-reporting polymer blends with orthogonal optical properties responsive in a broader force range

Empowering self-reporting polymer blends with orthogonal optical properties responsive in a broader force range

Poly(l-lactic acid) Microdomain as a Nanopolarization Rotator in a Flexible, Elastic, and Transparent Polyurethane

Shape memory thin films of polyurethane: Synthesis, characterization, and recovery behavior

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