Dangling Chains Research Articles

Controllable wide temperature range and high damping polyurethane elastomer based on disulfide bond and dangling chain

AbstractAiming at the common problems of weak controllability of damping temperature range and poor mechanical properties in damping elastomer materials. Herein, we design a polyurethane‐containing dynamic disulfide bonds and dangling chains to address this dilemma. The as‐prepared polyurethane exhibits an unprecedented damping range of 182°C (−62 to 120°C), and the tensile strength reaches 6.8 MPa, which is at the forefront of the same type of research. We innovatively introduce aromatic disulfides to the system, in which disulfide bonds can be spontaneously exchanged dynamically at room temperature, making the damping performance of the elastomer above room temperature improved, and a small amount of hydroxyl‐terminated polydimethylsiloxane (OH‐PDMS) is used as a dangling chain to promote the damping property of the elastomer between the glass transition temperature and room temperature. The synergistic effect of disulfide bonds and dangling chains makes the controllability of polyurethane damping temperature range realized. Furthermore, polyurethane elastomer is equipped with good thermal stability duo to the introduction of OH‐PDMS. And, the high‐performance polyurethane elastomer has great potential in practical application.

Library of Derivatizable Multiblock Copolymers by Nucleophilic Substitution Polymerization and Targeting Specific Properties.

Multiblock copolymers (MBCs) are fascinating in the field of biology-polymer chemistry interfaces. Synthesizing libraries of MBCs with tailor-made functionality is challenging as it involves multiple steps. Herein, a simple synthesis, analogous to polyurethane/Michael addition reactions, has been introduced to obtain a library of derivatizable MBCs. Nucleophilic substitution polymerization (SNP) of poly(ε-caprolactone) and poly(ethylene glycol) blocks containing activated halide termini by primary mono/di/coamines or clickable amines provides functional MBCs. The structure of amines directs the properties of the MBCs. The self-assembly of small molecular weight primary diamine-based MBCs shows controlled release of hydrophobic model guest molecules and therapeutics. The primary diamine (no dangling chain) helps to form MBC micelles having a relatively tight core with a low diffusion property. Antimicrobial property in the MBCs has been introduced by separating the cationic centers from the lipophilic groups using a coamine as a nucleophilic agent and a small molecular weight dihalide as a chain extender. Clickable MBCs were synthesized by changing the structure of the nucleophile to obtain degradable amphiphilic conetworks and hydrogels. Varieties of macromolecular entities could be obtained by switching the nucleophilic agent and introducing a small molecular weight chain extender. This synthesis approach provides an opportunity to tune the chemical functionality, topological structure, and biological properties of macromolecular entities.

Microstructure-driven self-assembly and rheological properties of multi-responsive soft microgel suspensions

HypothesesThe deformation and swelling ability of microgels is influenced by the crosslinking distribution. Varying microgels microstructure is expected to obtain suspensions with different flow behavior and thereby, different rheological properties. ExperimentsDifferent multi-responsive microgels were synthesized using two different crosslinkers and varying their amounts: N,N-methylene bis-acrylamide (MBA) and oligo(ethylene glycol) diacrylate (OEGDA). The rheological results were obtained by zero-shear viscosity and long-time creep measurements on concentrated microgel suspensions Microgel microstructure was analyzed by 1H nuclear magnetic resonance transverse relaxation measurements. FindingsAt a constant crosslinking rate, we show that the viscosity of OEGDA-crosslinked microgels diverges at a higher concentration than MBA ones, suggesting a looser shell and less restricted dangling chains at the periphery for the later. By scaling with the effective volume fraction, the viscosity curves of the different microgel suspensions reduce into a single curve and closely follow hard sphere models up to ϕeff < 0.45. The results from creep tests revealed a much higher yield stress for MBA-crosslinked microgels, strengthening the hypothesis of a looser shell for the later. Finally, transverse relaxation (T2) NMR measurements demonstrated that, although all microgels exhibit a core–shell microstructure, MBA samples present a less crosslinked shell corroborating with the rheological results.

Hydrophilic dangling chain interfacial segregation in polyurethane networks at aqueous interfaces and its underlying mechanisms: molecular dynamics simulations.

Polymer networks with hydrophilic dangling chains are ideal candidates for many submerged applications, e.g., protein non-adhesive coatings with non-fouling behavior. The dangling chains segregate from the polymer network towards the water and form a brush-like structure at the interface. Several factors such as the polymer network structure, dangling chain length, and water/dangling chain interaction may all affect the interfacial performance of the polymer. Therefore, we employed a Martini based coarse-grained (CG) molecular dynamics (MD) simulation to elucidate the influences of the abovementioned parameters on dangling chain interfacial segregation. We built up several polyurethane (PU) networks based on poly(tetra methylene glycol) (PTMG), as a macrodiol, and methoxy poly(ethylene glycol) (mPEG), as a dangling chain, with varying molecular weights. We found out that the macrodiol/dangling chain length ratio considerably smaller than one impedes the migration of dangling chains towards the water interface, while the dangling chain hydrophilicity and length determine the polymer interfacial layer density/thickness. Then, we artificially changed the dangling chain affinity to water from an intermediate to a very attractive water/dangling chain interaction. We justified that a brush-like structure forms in two consecutive steps: first, a longitudinal, and then a lateral migration of dangling chains in water. The latter step results in a uniform interfacial layer over the polymer interface that mainly occurs in the case of the attractive water/dangling chain interaction.

Preparation of polyurethanes with broad damping temperature range and self-healing properties

It is urgent for polyurethane (PU) damping materials to broaden the effective damping range. Based on the designability of PU, this study is focused on the role of long dangling chain, wherein prepared by the reaction of polyethylene glycol monomethyl ether with toluene-2,4-diisocyanate. Notably, the introduction of long dangling chain not only makes the dangling chain longer and enhances the intermolecular interaction but also equips the dangling chain with strong polar carbamate group, bringing about more excellent compatibility of the soft and hard segments and lower degree of microphase separation under the condition of hydrogen bonding. The results show that the damping performance increases with the synergistic effect of significant hydrogen bonding and decreased degree of microphase separation, and the effective damping temperature range (tan δ ≥ 0.3) can exceed 150°C (−50°C to 100°C). Simultaneously, the addition of long dangling chains endows PU with self-healing property, the self-healing rate of system reaches maximum 70% with shore A hardness of 15 because of the synergistic effect above with the addition of 60% dangling chain, which extends the service life of PU damping materials.

Design of dual hydrophobic–hydrophilic polymer networks for highly lubricious polyether-urethane coatings

Bio-lubricated surfaces found in nature have inspired the design of low friction polymer coatings for biomedical applications. This work presents a systematic study of the relation between the network structure parameters and the macroscopic friction properties of highly lubricious dual hydrophobic/hydrophilic polyurethane (PU) coatings in an aqueous environment. Chemically cross-linked PU coatings were prepared by adding poly(ethylene glycol) mono-methyl ether (mPEG) as hydrophilic dangling chains, or poly(ethylene glycol) (PEG)-diol as hydrophilic elastically active network chains, to poly(propylene glycol) (PPG)-PU coating formulations. The friction behaviour of the water swollen coatings was measured using a custom-made water immersed tribology setup. Addition of the PEG segments or mPEG dangling chains to hydrophobic PPG coatings greatly enhances the lubricious properties of the coatings. These dual hydrophobic/hydrophilic diol PU network exhibit a surface with a lower coefficient of friction compared to reference coatings from either individual precursors, demonstrating a large synergistic effect between the hydrophobic PPG and the hydrophilic PEG in the coatings. Based on network structure and surface chain considerations it is hypothesized that the existence of a thin and softer hydrated surface layer on top of a less hydrated, more rigid, coating bulk layer gives rise to the observed enhanced lubricious properties, hereby mimicking to some extent bio-lubricated systems, such as cartilage.

Inner relationship between the damping property and the sand‐fixing durability of polymer materials

ABSTRACTThis article for the first time reveals the impact of the damping property of materials on its sand‐fixing durability. Based on the turbulence of wind, it could be regarded as a kind of periodic mechanical force. So, when polymers are used to fix sand, they would constantly perceive a periodic force of wind. And, this force would give rise to yielding fracture and fatigue of polymer, so that the sand‐fixing durability of material could be weakened significantly. To impair the periodic force of wind and extend the durability of sand‐fixation polymer materials, we, for the first time, introduce the designing principle of macromolecular damping material, that can transform external mechanical force into own thermal energy, into the preparation of sand‐fixing materials. In this work, poly(vinyl acetate) (PVAc) emulsions with different dangling chain have been synthesized successfully in order to improve their damping properties. The effects of the prepared PVAc with gradually growing dangling chain length have been investigated on their damping properties, on the sand stabilization strengths and sand‐fixing durability. And the relationship between the damping property and the sand‐fixing property of PVAc was built by simulating wind tunnel test. The experimental results show that, introducing the dangling chain could significantly improve the damping temperature range and extend the anti‐wind erosion time of PVAc. It has to be noticed that, introducing the dangling chain, will provide a double effects for the sand stabilization strength of materials, i.e., it can improve both the flexibility of the side‐chain and the internal friction of the molecular chains. Wind tunnel test verified that introducing the dangling chain can raise the damping performance of material and convert more periodic force of wind into the friction heat of molecular chain, and thus impair the damage of wind on the materials and improve their anti‐wind erosion properties. These findings suggest that the damping material applied in sand fixation is a bright idea and successful method for improving the sand‐fixing durability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47208.

Hydrophilic Self-Replenishing Coatings with Long-Term Water Stability for Anti-Fouling Applications

Hydrophilic coatings have recently emerged as a new approach to avoiding the adhesion of (bio)organisms on surfaces immersed in water. In these coatings the hydrophilic character is crucial for the anti-fouling (AF) performance. However, this property can be rapidly lost due to the inevitable damages which occur at the surface, reducing the long-term effectiveness of the AF functionality. We report hydrophilic polycarbonate-poly(ethylene glycol) methyl ether (mPEG) polyurethane coatings with tunable hydrophilic properties as well as an excellent and long-term stability in water. The coatings exhibit low protein adhesion values and are able to self-replenish their hydrophilicity after damage, due to the existence of a reservoir of hydrophilic dangling chains incorporated in the bulk. The combination of low Tg and sufficient mobility of the mPEG dangling chains (enabled by chains with higher molecular weight) proved to be crucial to ensure autonomous surface hydrophilicity recovery when the coatings were immersed in water. This coatings and design approach offers new possibilities towards high-performance AF coatings with an extended service life-time which can be used in several major applications areas, such as marine and biomedical coatings, with major economic and environmental benefits.

Mechanical response of transient telechelic networks with many-part stickers.

A central question in soft matter is understanding how several individual, weak bonds act together to produce collective interactions. Here, gel-forming telechelic polymers with multiple stickers at each chain end are studied through Brownian dynamics simulations to understand how collective interaction of the bonds affects mechanical response of the gels. These polymers are modeled as finitely extensible dumbbells using an explicit tau-leap algorithm and the binding energy of these associations was kept constant regardless of the number of stickers. The addition of multiple bonds to the associating ends of telechelic polymers increases or decreases the network relaxation time depending on the relative kinetics of association but increases both shear stress and extensional viscosity. The relationship between the rate of association and the Rouse time of dangling chains results in two different regimes for the equilibrium stress relaxation of associating physical networks. In case I, a dissociated dangling chain is able to fully relax before re-associating to the network, resulting in two characteristic relaxation times and a non-monotonic terminal relaxation time with increasing number of bonds per polymer endgroup. In case II, the dissociated dangling chain is only able to relax a fraction of the way before it re-attaches to the network, and increasing the number of bonds per endgroup monotonically increases the terminal relaxation time. In flow, increasing the number of stickers increases the steady-state shear and extensional viscosities even though the overall bond kinetics and equilibrium constant remain unchanged. Increased dissipation in the simulations is primarily due to higher average chain extension with increasing bond number. These results indicate that toughness and dissipation in physically associating networks can both be increased by breaking single, strong bonds into smaller components.

Highly Responsive Hydrogel Prepared Using Poly(N-isopropylacrylamide)-Grafted Polyrotaxane as a Building Block Designed by Reversible Deactivation Radical Polymerization and Click Chemistry

We prepared building blocks with the ability to form a polymer network, a polyrotaxane (PR) structure that enhances the flexibility of the polymer network, and thermosensitive dangling chains that impart the polymer network with rapid sensitivity. First, thermosensitive poly(N-isopropylacrylamide) (PNIPA) was grafted from α-cyclodextrin, a cyclic molecule of PR, via controlled radical polymerization. The terminal chlorinated alkyl group of the grafted PNIPA was then modified with azide or alkyne. As a result, we obtained two types of PNIPA-grafted PR molecules with different terminations of PNIPA as building blocks. We then prepared a polymer network in which PR molecules with several dangling PNIPA chains were connected by PNIPA chains using a click reaction. Because of the presence of the dangling PNIPA chains, the obtained hydrogel exhibits rapid responses to changes in water temperature; it also exhibits flexibility due to the presence of the PR structure.

Raman spectroscopy study on influence of network architecture on hydration of poly(2‐(2‐methoxyethoxy)ethyl methacrylate) hydrogels

Thermo‐responsive polymer hydrogels attract a great attention because of their unique behavior in response to changes in the thermal environment. It is related to metastable intermolecular interactions resulting in volume phase transitions (VPT). The hydration of poly(2‐(2‐methoxyethoxy)ethyl methacrylate) (PMEO2MA)‐based materials was studied by Raman spectroscopy and further supported by density functional theory calculations. Hydrogels based on random networks prepared via radiation‐induced free radical polymerization and cross‐linking were compared with hydrogels with more regular structure formed by atom transfer radical polymerization. Two types of regular networks were studied: bare one and decorated by linear dangling chains. It was found that both, the total bound water surrounding the polymer chains (~11 H2O per polymer unit) and accessibility of CO groups for water molecules, are independent of topology of PMEO2MA network. Contrarily, network architecture strongly influences CO–water complex stability, which decreases in a following order: regular bare network, irregular bare network, regular decorated network. It was also shown that the stability of CO–water complex is correlated with VPT temperature in PMEO2MA hydrogels. These studies prove a key role of polymer hydration in its thermo‐responsive properties. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Scaling laws of gelatin hydrogels for steady dynamic friction

In this article, we use population balance based dynamic friction model for steady sliding to develop scaling laws in the terms of mesh size of gelatin hydrogels. First of all, it is observed in the sliding experiments that shear modulus of gelatin hydrogels depends on sliding velocity. This dependence is more evident in the case of low sliding velocity. Moreover, relaxation time constant of a dangling chain at the sliding interface scales with the same exponent as its stiffness. The scaling law is also developed for chain density and viscous retardation at the sliding interface. It is also established that the Hookean-based dynamic friction model is sufficient to study frictional behaviour of hydrogels. The reason for this observation is attributed to the weak bonding between a gelatin hydrogel and glass interface.

Structure, morphology and properties of epoxy networks with dangling chains cured by anhydride

A series of epoxy networks containing side aliphatic dangling chains were prepared by the curing reaction of bisphenol F diglycidyl ether (DGEBF), the monofunctional epoxy (including n-butyl, dodecyl, cetyl) and the anhydride.

Morphology and high-performance of in-situ self-assemble epoxy resin with side aliphatic dangling chains

A series of epoxy resins containing side aliphatic pendant chains (abbreviated as EPC-04, EPC-08, EPC-12 and EPC-18) were prepared by the reaction between the diglycidyl ether of bisphenol F (DGEBF) and the single-ended fatty amine with a chain length ranging from C4 to C18. Studies on the film morphology and the physical performance demonstrate that the cured EPC-04, EPC-08, EPC-12 and EPC-18 composites possess excellent mechanical and thermal properties, which are originated from the micro-, submicro- and nano-structured phases distributed in the epoxy matrix. In addition, by adjusting the lengths of the dangling aliphatic chains, the mechanical properties of the cured resins can be tuned in different scales. Consequently, by prolonging the pendant chain length to C18, the cured resin exhibits a striking tensile strength of 90.65MPa, an elongation of 6.1% and a modulus of 2.55GPa.

Surface peeling of cellulose nanocrystals resulting from periodate oxidation and reductive amination with water-soluble polymers

Cellulose nanocrystals (CNCs) were first submitted to periodate oxidation for increasing reaction times and subsequently to reductive amination with water-soluble amine-terminated polymers. The morphology and chemical properties of the samples were characterized by imaging (TEM), spectroscopic (FTIR and 13C solid-state NMR), and scattering techniques (DLS and WAXS). The data revealed that the periodate oxidation of CNCs resulted in an increase in the degree of oxidation (DO) with reaction time and that most of the created carbonyls were converted into hemiacetals as a result of their interaction with vicinal hydroxyl groups. Like in the case of cellulose microfibrils, CNCs were oxidized from the surface to the core of the particles. For low reaction times and concomitant low DOs, the morphology and crystallinity of the CNCs were mildly altered. A prolonged oxidation resulted in the separation of the originally laterally assembled crystallites and the data are consistent with the presence of dangling chains resulting from the cleavage of glucosyl units at the surface of the thin elongated cellulose nanoparticles. A comparison with literature data further showed that the oxidation reaction was not primarily governed by the degree of crystallinity. Remarkably, after reductive amination with water-soluble polymer chains, thin unoxidized crystalline cellulose nanoparticles were recovered. This situation seems to result from the surface peeling of the CNCs due to reaction of surface-oxidized dangling chains with water-soluble polymers and their subsequent solubilization.

Structure and Properties of fac-[Re(I)(CO)3(NTA)](2-) (NTA(3-) = Trianion of Nitrilotriacetic Acid) and fac-[Re(I)(CO)3(L)](n-) Analogues Useful for Assessing the Excellent Renal Clearance of the fac-[(99m)Tc(I)(CO)3(NTA)](2-) Diagnostic Renal Agent.

We previously identified two new agents based on the [(99m)Tc(V)O](3+) core with renal clearances in human volunteers 30% higher than that of the widely used clinical tracer (99m)Tc-MAG3 (MAG3(5-) = penta-anion of mercaptoacetyltriglycine). However, renal agents with even higher clearances are needed. More recently, we changed our focus from the [(99m)Tc(V)O](3+) core to the discovery of superior tracers based on the fac-[(99m)Tc(I)(CO)3](+) core. Compared to (99m)Tc-MAG3, fac-[(99m)Tc(I)(CO)3(NTA)](2-) (NTA(3-) = trianion of nitrilotriacetic acid) holds great promise by virtue of its efficient renal clearance via tubular secretion and the absence of hepatobiliary elimination, even in patients with severely reduced renal function. We report here NMR, molecular (X-ray) structure, and solution data on fac-[Re(I)(CO)3(NTA)](2-) with a -CH2CO2(-) dangling monoanionic chain and on two fac-[Re(I)(CO)3(L)](-) analogues with either a -CH2CONH2 or a -CH2CH2OH dangling neutral chain. In these three fac-[Re(I)(CO)3(L)](n-) complexes, the fac-[Re(I)(CO)3(N(CH2CO2)2)](-) moiety is structurally similar and has similar electronic properties (as assessed by NMR data). In reported and ongoing studies, the two fac-[(99m)Tc(I)(CO)3(L)](-) analogues with these neutral dangling chains were found to have pharmacokinetic properties very similar to those of fac-[(99m)Tc(I)(CO)3(NTA)](2-). Therefore, we reach the unexpected conclusion that in fac-[(99m)Tc(I)(CO)3(L)](n-) agents, renal clearance is affected much more than anticipated by features of the core plus the chelate rings (the [(99m)Tc(I)(CO)3(N(CH2CO2)2)](-) moiety) than by the presence of a negatively charged dangling carboxylate chain.

Reprocessing and Recycling of Highly Cross-Linked Ion-Conducting Networks through Transalkylation Exchanges of C-N Bonds.

Exploiting exchangeable covalent bonds as dynamic cross-links recently afforded a new class of polymer materials coined as vitrimers. These permanent networks are insoluble and infusible, but the network topology can be reshuffled at high temperatures, thus enabling glasslike plastic deformation and reprocessing without depolymerization. We disclose herein the development of functional and high-value ion-conducting vitrimers that take inspiration from poly(ionic liquid)s. Tunable networks with high ionic content are obtained by the solvent- and catalyst-free polyaddition of an α-azide-ω-alkyne monomer and simultaneous alkylation of the resulting poly(1,2,3-triazole)s with a series of difunctional cross-linking agents. Temperature-induced transalkylation exchanges of C-N bonds between 1,2,3-triazolium cross-links and halide-functionalized dangling chains enable recycling and reprocessing of these highly cross-linked permanent networks. They can also be recycled by depolymerization with specific solvents able to displace the transalkylation equilibrium, and they display a great potential for applications that require solid electrolytes with excellent mechanical performances and facile processing such as supercapacitors, batteries, fuel cells, and separation membranes.

Unusual Example of Chelate Ring Opening upon Coordination of the 9-Ethylguanine Nucleobase to [Pt(di-(6-methyl-2-picolyl)amine)Cl]Cl.

Anticancer-active monofunctional Pt(II) complexes have bulky carrier ligands and bind to G residues in DNA, causing structural distortions. To gain fundamental chemical information on such monofunctional adducts, we assessed the 9-ethylguanine (9-EtG) adducts formed by [Pt(N(H)6,6'-Me2dpa)Cl]Cl (N(H)6,6'-Me2dpa = di-(6-methyl-2-picolyl)amine). 9-EtG added to [Pt(N(H)6,6'-Me2dpa)Cl]Cl to form not only the expected [Pt(N(H)6,6'-Me2dpa)(9-EtG)](2+) monoadduct having syn and anti conformers but also a [Pt(N(H)6,6'-Me2dpa)(9-EtG)2](2+) bisadduct consisting of ΛHT and ΔHT conformers (HT = head-to-tail). For both adducts, the two conformers exist as a dynamic equilibrium mixture. Concomitant with formation of the bisadduct, the binding mode of the N(H)6,6'-Me2dpa ligand converts from tridentate to bidentate. A Pt(II)-bound 6-methyl-2-picolyl chain and the secondary amine constitute the bidentate chelate ring. The other 6-methyl-2-picolyl chain is dangling. The secondary nitrogen is an asymmetric center, and each conformer exists as a racemic mixture of two enantiomers. For a given configuration at the secondary amine of the [Pt(N(H)6,6'-Me2dpa)(9-EtG)2](2+) adduct, the more abundant HT conformer can form a hydrogen bond between the NH of the bidentate ligand and the cis 9-EtG O6. [Pt(N(H)6,6'-Me2dpa)Cl]Cl forms the monoadduct in ∼1/20 the time for its parent, [Pt(N(H)dpa)Cl]Cl (N(H)dpa = di(2-picolyl)amine), which exhibited typical behavior in forming only a monoadduct. We attribute the unusual new findings for [Pt(N(H)6,6'-Me2dpa)Cl]Cl to Pt-N bond weakening induced by the steric bulk of 6/6'-Me groups. We hypothesize that undetectable intermediates with a dangling 6-methyl-2-picolyl chain facilitate both rapid monoadduct formation and also bisadduct formation. Consistent with the intermediacy of such species with a dangling chain, addition of HCl to a [Pt(N(H)6,6'-Me2dpa)Cl]Cl solution readily produced a dichloro complex with the N(H)6,6'-Me2dpa chelate ligand in the bidentate mode, whereas HCl addition had no effect on [Pt(N(H)dpa)Cl]Cl.

Photopolymerized Network Polysiloxane Films with Dangling Hydrophilic/Hydrophobic Chains for the Biofouling Release of Invasive Marine Serpulid Ficopomatus enigmaticus.

Novel photopolymerized network films based on a polysiloxane matrix containing varied amounts of polyoxyethylene (P3) or perfluorohexylethyl (F) dangling side chains were investigated. For films containing less than 10 wt % P3 and F, the wettability and elastic modulus were similar to those of the photopolymerized network matrix. However, angle-resolved X-ray photoelectron spectroscopy measurements proved that the surface of films with F dangling chains was highly enriched in fluorine depending on both the amount of P3 and F and their relative ratio in the films. The biological performance of the films was evaluated against a new widespread and invasive marine biofoulant, the serpulid Ficopomatus enigmaticus. The diatom Navicula salinicola was also assayed as a conventional model organism for comparison. Films richer in P3 better resisted the settlement and promoted the release of calcified tubeworms of F. enigmaticus.

Effect of the hard segment structure on properties of resorcinol derivatives-based polyurethane elastomers

Two series of polyurethane elastomers were obtained from poly(1,4-butylene adipate) diol and 1,6-diisocyanatohexane, which were then chain extended with resorcinol derivatives such as benzene-1,3-diol, 2,4-dihydroxybenzaldehyde, or 1-(2,4-dihydroxyphenyl) hexan-1-one. This article investigates the effects induced in polyurethane elastomer properties by varying the hard segment composition through changing the amount of aliphatic diisocyanate and through the influence of the chemical structure of the resorcinol derivatives’ chain extenders. The different chemical composition and the presence of different dangling chains on the chain extender structure influenced hard segment cohesion, resulting in important effects on the polyurethane elastomer properties. The incorporation of aliphatic diisocyanate alongside the aromatic chain extender leads to changes in the physical and mechanical properties of the polyurethane elastomers compared with aromatic rigid diisocyanates. These polyurethane elastomers were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and mechanical measurements. We synthesized resorcinol-based polyurethane elastomers with aliphatic–aromatic hard segment structures, with the resorcinol addition making it unnecessary to transform phenolic OH groups into aliphatic OH groups.