Polyurethane elastomers based on amphiphilic poly(caprolactone)‐b‐poly(butadiene)‐b‐poly(caprolactone) triblockcopolyols

Abstract

Hydroxyl-terminated poly(butadiene) (HTPB; M n 5 2100 g mol 21 ) was capped with 30 and 60 wt % of E-caprolactone to reach amphiphilic triblock copolymers in form of capped poly(butadiene) CPB. The former (CPB30; M n 5 3300 g/mol) is amorphous with a glass temperature of 256 8C. CPB60 (M n 5 4000 g mol 21 ) is semi-crystalline with a melting point of 50 8C and a glass transition at 247 8C. The CPBs, HTPB and polycaprolactone diol (M n 5 2000 g mol 21 ) were used as soft segment components in the preparation of polyurethane elastomers (PUE), using a 1/1 mixture of an MDI prepolymer and uretonimine modified MDI, and hard phase components in form of 1,3-propane diol, 1,4butane diol, and 1,5-pentane diol. CPB-based elastomers with 1,4 butane diol (8 wt %) show hard domains as fringed aggregates with a better connection to the continuous phase than the HTPBbased PUE. The soft segment glass transition temperature (T g ) is at 228 8C for HTPB-based PUE and at 243 8C for those of CPB. The tensile strength of the CPB30&60-based PUE is found between 20 and 30 MPa at an elongation at break of 400% and 550%, respectively.

Hydrolysis‐resistant polyurethane elastomers synthesized from hydrophobic bio‐based polyfarnesene diol

“…Moreover, the unique "bottle brushes" structure of PFD makes PUEs exhibit a lower T g, SS than that of most HTPB-based PUEs with similar HS composition and HSC. 35,39 As shown in Figure 4 and Table III, △H MMT and △H M increased with the increasing of HSC. This indicated that the increase of average HS length favors the formation of mixed phase and well-ordered HS phase.…”

“…Prominent extent of phase separation might be the main reason that causes virtually constant values of T g , SS and T g , HS . Moreover, the unique “bottle brushes” structure of PFD makes PUEs exhibit a lower T g , SS than that of most HTPB‐based PUEs with similar HS composition and HSC . As shown in Figure and Table , ▵ H MMT and ▵ H M increased with the increasing of HSC.…”

Super stretchable chromatic polyurethane driven by anthraquinone chromogen as a chain extender

“…Shore A hardness of PUEs corresponding to different contents of chromogen is largely inuenced by the content and the morphology of the hard phase, and the values are consistent with so rubbers. 34 The hardness of the PUE lms are affected by many factors such as H-bonding, phase separation and crosslink density. In contrast, the Shore A hardness for BPUE 10 (10% molar ratio chromogen) is much lower (Shore A 61.7), which may be caused by an overdose of chromogen affecting hydroxyl activity.…”

Synthesis and properties evaluation of quaternized polyurethanes as antibacterial adhesives

“…Polyurethane is an interesting polymer applied for a range of applications in different forms as elastomer, thermoplastic, sponges, and foams . For most of the applications in the biomedical field, textile, shoe sole, mattresses, adhesives, and so on, antibacterial property adds on to its properties profile …”

“…9,10 Polyurethane is an interesting polymer applied for a range of applications in different forms as elastomer, thermoplastic, sponges, and foams. [11][12][13][14][15][16] For most of the applications in the biomedical field, textile, shoe sole, mattresses, adhesives, and so on, antibacterial property adds on to its properties profile. 17,18 The metal and metal oxide nanoparticles, such as silver, copper, Ni, and ZnO can be either extruded with PU or used during in situ formation of PU to achieve antibacterial activity.…”