Polymer Relaxation Research Articles

Techniques of Mucilage and Gum Modification and their Effect on Hydrophilicity and Drug Release.

The manuscript aims to describe the techniques of modification of gums and mucilages and their effect on hydrophilicity and drug release. The interest is increased in the fields of polymers which are obtained from natural origin and used in the preparation of pharmaceuticals. Mucilage and gum are natural materials widely used in the preparation of novel dosage and conventional dosage forms. They are used in the pharmaceutical industry for various purposes like suspending, emulsifying, bio-adhesive, binding, matrix-forming, extended release and controlled release agent. Gum and mucilage are biodegradable, less toxic, cheap and easily available. Moreover, mucilage and gum can be changed to acquire tailored materials for the delivery of drugs and allow them to compete with commercially available synthetic products. These polysaccharides have unique swellability in an aqueous medium that can exert a retardant effect on drug release or act as a super disintegrant, depending on the concentration utilized in the preparation. Drug release mechanism from hydrophilic matrices consisting of gums and mucilages is based on solvent penetration-induced polymer relaxation, diffusion of entrapped drug followed by degradation or erosion of the matrix. The present manuscript highlights the advantages, modifications of gum and mucilage, their effects on hydrophilicity and drug release as well as aspects of the natural gums which can be assumed to be bifunctional excipient because of their concentration-dependent effect on drug release and their high degree of swellability.

A lattice Boltzmann modeling of viscoelastic drops’ deformation and breakup in simple shear flows

The deformation and breakup of viscoelastic drops in simple shear flows of Newtonian liquids are studied numerically. Our three-dimensional numerical scheme, extended from our previous two-dimensional algorithm, employs a diffusive-interface lattice Boltzmann method together with a lattice advection–diffusion scheme, the former to model the macroscopic hydrodynamic equations for multiphase fluids and the latter to describe the polymer dynamics modeled by the Oldroyd-B constitutive model. A block-structured adaptive mesh refinement technique is implemented to reduce the computational cost. The multiphase model is validated by a simulation of Newtonian drop deformation and breakup under an unconfined steady shear, while the coupled algorithm is validated by simulating viscoelastic drop deformation in the shear flow of a Newtonian matrix. The results agree with the available numerical and experimental results from the literature. We quantify the drop response by changing the polymer relaxation time λ and the concentration of the polymer c. The viscoelasticity in the drop phase suppresses the drop deformation, and the steady-state drop deformation parameter D exhibits a non-monotonic behavior with the increase in Deborah number De (increase in λ) at a fixed capillary number Ca. This is explained by the two distribution modes of the polymeric elastic stresses that depend on the polymer relaxation time. As the concentration of the polymer c increases, the degree of suppression of deformation becomes stronger and the transient result of D displays an overshoot. The critical capillary number for unconfined drop breakup increases due to the inhibitive effects of viscoelasticity. Different distribution modes of elastic stresses are reported for different De.

Alginate-chitosan/MWCNTs nanocomposite: a novel approach for sustained release of Ibuprofen

The use of alginate as excipient in dosage formulation is a common trend due to mild gelling ability, biocompatibility, biodegradability, non-toxicity, and mucoadhesive properties. However, these formulations possess major disadvantages, such as rapid hydration, burst release, and difficulty in controlling the process. Hence, this study presents a novel water-insoluble alginate-chitosan/MWCNTs formulation having greater porosity (Surface area 7.854 m2/g) with mechanical (Youngs Modulus 249.17 N/mm) and thermal stability (stable up to 570 ℃). Ibuprofen was selected as a model drug to evaluate the entrapment efficiency and sustained delivery from synthesized excipients. The structure of successfully prepared nanocomposite is characterized by FTIR, SEM, TEM, TGA/DSC, XRD, BET, and tensile testing. It was observed that ibuprofen was successfully encapsulated (88%) in CD90 formulation. COOH-MWCNTs nanofillers improved the releasing capacity of alginate-based formulation (CD90) and prolonged the sustained delivery (68%, obtained in 6 h). It is explored that polymer nanocomposite composed of alginate-chitosan/MWCNTs are sensitive to temperature and pH. The kinetic processes followed by ibuprofen to diffuse from the synthesized formulations are first-order, non-Fickian, and intraparticle diffusion in which the rate of ibuprofen diffusion is greater than the polymer relaxation.

Bioinspired Self-Assembled 3D Patterned Polymer Textures as Skin Coatings Models: Tribology and Tactile Behavior

It is well known that during evolution, specific surface patterns emerged (e.g., on lotus leaves and butterfly wings) endowed with many remarkable surface properties (superhydrophobicity, vibrant structural color, delicate textures, etc.). In order to obtain these natural effects in cosmetics, we look for ways to transfer topographic patterns in coatings and treatments. Textured polymer surfaces were studied to explore their friction properties on the microscale and possible correlations with human tactile friction on the macroscale. We have chosen self-assembling block and random copolymers as model systems to prepare reliable biomimetic films with different micrometer and nanometer scale randomly patterned and randomly rough surfaces. The surface texture of the films was characterized by atomic force microscopy (AFM), and their tribological (friction) properties were studied with a surface forces apparatus (SFA) at a low sliding speed of 3 μm/s and at a speed of 10 cm/s relevant to realistic applications. The results are evaluated in terms of polymer segment mobility, interpenetration, entanglement and relaxation at interfaces, surface texture as described by roughness parameters, and interlocking of asperities. A stiction spike (static friction) was commonly found for the randomly patterned glassy polymer films. Random roughness patterns made from semi-crystalline polymers above their Tg gave high friction at low speed, but their friction coefficients were reduced at high speed due to less time for local entanglement and relaxations. The friction response of one of them was also affected differently by humidity than that of glassy polymer films. Tactile friction measurements with a human finger sliding against the polymer films revealed that the textures also provided differences at the macroscale, although the dynamic changes possibly due to lipid transfer, occlusion of moisture and/or damage of the films makes it difficult to draw robust conclusions. Finally, as an example, it is shown that these textures can be transferred to a soft elastomeric skin mimic substrate. This study introduces the concept of surface patterning by self-assembly to deliver tactile sensorial properties in coatings.

Interplay of the Assembly Conditions on Drug Transport Mechanisms in Polyelectrolyte Multilayer Films.

The layer-by-layer film deposition is a suitable strategy for the design and functionalization of drug carriers with superior performance, which still lacks information describing the influence of assembly conditions on the mechanisms governing the drug release process. Herein, traditional poly(acrylic acid)/poly(allylamine) polyelectrolyte multilayers (PEM) were explored as a platform to study the influence of the assembly conditions such as pH, drug loading method, and capping layer deposition on the mechanisms that control the release of calcein, the chosen model drug, from PEM. Films with 20–40 bilayers were assembled at pH 4.5 or 8.8, and the drug loading process was carried out during- or post-film assembly. Release data were fitted to three release models, namely, Higuchi, Ritger–Peppas, and Berens–Hopfenberg, to investigate the mechanism governing the drug transport, such as the apparent diffusion and the relaxation time. The postassembly drug loading method leads to a higher drug loading capacity than the during-assembly method, attributed to the washing out of calcein during film assembly steps in the latter method. Higuchi’s and Ritger–Peppas’ model analyses indicate that the release kinetic constant increased with the number of bilayers for the postassembly method. The opposite trend is observed for the during-assembly method. The Berens–Hopfenberg release model enabled the decoupling of each drug transport mechanism’s contribution, indicating the increase of the diffusion contribution with the number of bilayers for the postassembly method at pH 4.5 and the increase of the polymer relaxation contribution for the during-assembly method at pH 8.8. Deborah’s number, which represents the ratio of the polymer relaxation time to the diffusion time, follows the trends observed for the relaxation contribution for the conditions investigated. The deposition of the capping phospholipid layer over the payload also favored the polymer relaxation contribution in the drug release, featuring new strategies to investigate the drug release in PEM.

Dynamic Bonds Mediate π-π Interaction via Phase Locking Effect for Enhanced Heat Resistant Thermoplastic Polyurethane

Stimulus-responsive polymers containing dynamic bonds enable fascinating properties of self-healing, recycling and reprocessing due to enhanced relaxation of polymer chain/network with labile linkages. Here, we study the structure and properties of a new type of thermoplastic polyurethanes (TPUs) with trapped dynamic covalent bonds in the hard-phase domain and report the frustrated relaxation of TPUs containing weak dynamic bond and π-π interaction in hard segments. As detected by rheometry, the aromatic TPUs with alkyl disulfide in the hard segments possess the maximum network relaxation time in contrast to those without dynamic bonds and alicyclic TPUs. In situ FTIR and small-angle scattering results reveal that the alkyl disulfide facilitates stronger intermolecular interaction and more stable micro-phase morphology in π-π interaction based aromatic TPUs. Molecular dynamics simulation for pure hard segments of model molecules verify that the presence of disulfide bonds leads to stronger π-π stacking of aromatic rings due to both enhanced assembling thermodynamics and kinetics. The enhanced π-π packing and micro-phase structure in TPUs further kinetically immobilize the dynamic bond. This kinetically interlocking between the weak dynamic bonds and strong molecular interaction in hard segments leads to much slower network relaxation of TPU. This work provides a new insight in tuning the network relaxation and heat resistance as well as molecular self-assembly in stimulus-responsive dynamic polymers by both molecular design and micro-phase control toward the functional applications of advanced materials.

Stress relaxation, creep, and recovery of carbon fiber non-crimp fabric composites

Considering that structural composites are typically composed of off-axis plies, i.e. quasi-isotropic stacking sequence, their strength and stiffness are time-dependent due to the viscoelastic character of polymer matrices. This work consists of determining creep, recovery, and stress relaxation of carbon fiber-reinforced polymer (CFRP) composites. Long-term experimental analyses are conducted via dynamic mechanical analysis under several temperatures and stress levels. From the experimental observations, the changes in the relaxation mechanisms are predicted using Fancey's latch model. The rate of relaxation at different temperatures is also covered. Since at certain strain levels the viscoelastic behavior cannot be properly determined, the stress-relaxation is determined using the time-temperature superposition (TTS) principle, considering nine temperatures at three strain levels in order to cover the three main regions of the composite system (glassy, glass transition and rubbery regions). The models and experiments herein presented can be extended to any polymeric system.

Evaluation of chitosan-ferulic acid microcapsules for sustained drug delivery: Synthesis, characterizations, and release kinetics in vitro

Herein, bovine serum albumin (BSA) as model protein drug was loaded on chitosan-ferulic acid (CS-FA) conjugants as protein drug carrier through the spray drying technique. The successful graft copolymerization of chitosan with ferulic acid was confirmed with FT-IR and XRD analyses. Additionally, the results of UV–Vis confirmed that the bovine serum albumin loading in the chitosan-ferulic acid-bovine serum albumin microcapsule was about 15.93%, respectively. The thermal properties of the conjugates were evaluated by means of thermogravimetric analysis and differential scanning calorimetry. The results revealed that the chitosan-ferulic acid conjugates exhibited low crystallinity but high thermal stability compared with that of chitosan. The pharmacokinetic study demonstrated that the chitosan-ferulic acid conjugates could provide a significantly higher swelling ratio and superior in vitro sustained release property. Furthermore, the results of drug release mechanism exhibited the corrode model was more accurately described the drug release behaviour involving a combination of drug diffusion and polymer relaxation. All these properties made chitosan-ferulic acid conjugates have potential to be developed as an oral carrier in functional foods and drug delivery systems.

Slow Magnetic Relaxation in a One-Dimensional Coordination Polymer Constructed from Hepta-Coordinate Cobalt(II) Nodes

A one-dimensional coordination polymer was synthesized employing hepta-coordinate CoII as nodes and dicyanamide as linkers. Detailed direct current (DC) and alternating current (AC) magnetic susceptibility measurements reveal the presence of field-induced slow magnetic relaxation behavior of the magnetically isolated seven-coordinate CoII center with an easy-plane magnetic anisotropy. Detailed ab initio calculations were performed to understand the magnetic relaxation processes. To our knowledge, the reported complex represents the first example of slow magnetic relaxation in a one-dimensional coordination polymer constructed from hepta-coordinate CoII nodes and dicyanamide linkers.

Chitosan polyvinyl alcohol blend films for ibuprofen encapsulation: Fabrication, characterization and kinetics

Hereby, the effectiveness of ibuprofen release from chitosan/polyvinyl alcohol blend films prepared by solvent casting method was studied as a function of blend composition and cross-linking density. Genipin was used as the cross-linker. Miscibility of blend components was verified by FTIR and SEM analyses. Based on the results of ninhydrin assay, optimal genipin concentration was determined as 0.25 mM. Genipin induced inter and intramolecular hydrogen bonding aided in the enhancement of tensile strength and mechanical stability as shown with swelling tests. Concordantly, burst release was hindered and more efficient release profile was obtained for crosslinked blend. The kinetics of ibuprofen release was best described by Korsmeyer Peppas model implying that diffusion and polymer relaxation were the underlying mechanisms for either non-crosslinked or genipin cross-linked blends. Over 96% of cell viability was recorded in WST-1 assay. All these results suggested that ibuprofen encapsulated chitosan polyvinyl alcohol blends crosslinked by genipin could be used as pain suppressing wound dressing material.

Competition between Structural Relaxation and Crystallization in the Glass Transition Range of Random Copolymers.

Structural relaxation in polymers occurs at temperatures in the glass transition range and below. At these temperatures, crystallization is controlled by diffusion and nucleation. A sequential occurrence of structural relaxation, nucleation, and crystallization was observed for several homopolymers during annealing in the range of the glass transition. It is known from the literature that all of these processes are strongly influenced by geometrical confinements. The focus of our work is copolymers, in which the confinements are caused by the random sequence of monomer units in the polymer chain. We characterize the influence of these confinements on structure formation and relaxation in the vicinity of the glass transition. The measurements were performed with a hydrogenated nitrile-butadiene copolymer (HNBR). The kinetics of the structural relaxation and the crystallization was measured using fast differential scanning calorimetry (FDSC). This technique was selected because of the high sensitivity, the fast cooling rates, and the high time resolution. Crystallization in HNBR causes a segregation of non-crystallizable segments in the macromolecule. This yields a reduction in mobility in the vicinity of the formed crystals and as a consequence an increased amount of so-called “rigid amorphous fraction” (RAF). The RAF can be interpreted as self-assembled confinements, which limit and control the crystallization. An analysis of the crystallization and the relaxation shows that the kinetic of both is identical. This means that the Kohlrausch exponent of relaxation and the Avrami exponent of crystallization are identical. Therefore, the crystallization is not controlled by nucleation but by diffusion and is terminated by the formation of RAF.

Modified karaya gum colloidal particles for the management of systemic hypertension

This study undertakes the development of colloidal carriers for the purpose of oral delivery of bosentan and subsequent management of systemic hypertension. Karaya gum, a natural polymer was carboxymethylated to improve its hydrophilic character and then the carboxymethyl gum was hydrophobically modified by forming propyl ethers. The modified polymer acquired amphiphilic property and self-aggregated in water to form amphiphilic colloidal particles (ACPs) at critical concentration of 3.35 mg/L with spherical shape (<200 nm) and smooth surface morphology. The colloidal particles could entrap >90% drug in the lipophilic domain. The ionic crosslinking of the hydrophilic shell of ACPs imparted greater stability to the colloidal system. The crosslinking extended the duration of drug release under simulated gastrointestinal fluids. The crystalline drug physically turned into amorphous state after hosting into the lipophilic cores of ACPs. The entrapment resulted in significant improvement of drug dissolution rate. The polymer relaxation contributed to the diffusion process of drug from ACPs. Pre-clinical testing via oral route demonstrated that the crosslinked colloidal particles could effectively control the systemic hypertension over a period of 12 h. Hence, bosentan-loaded self-assembled colloidal particles may advance the management of systemic hypertension.

Dielectric properties of PVA cryogels prepared by freeze-thaw cycling.

Solutions of polyvinyl alcohol (PVA) in water can form gels upon repeated freezing and thawing. These PVA cryogels have applications as biomaterials, including artificial tissue and drug delivery systems. We have studied the dielectric properties of PVA cryogels within the freeze-thaw cycles as a function of both frequency and temperature in order to understand the physical changes that take place during the thermal cycling process. Our results indicate that most of the changes in dielectric properties occur during the cooling phase of the first cycle and suggest that the solution must be cooled below a critical temperature of about 263 K for the formation of a gel that persists after thawing. The material's dielectric spectrum shows the presence of several relaxation processes. We identify one of these with the dielectric relaxation of ice and two others with motions of the PVA polymer chains. The temperature dependence of the polymeric relaxation times suggests that they are both thermally activated, with an activation energy of roughly 300 kJ/mol.

Wetting and Chain Packing across Interfacial Zones Affect Distribution of Relaxations in Polymer and Polymer-Grafted Nanocomposites

Polymers exhibit deviations from their bulk physical properties in the vicinity of solid interfaces due to changes in configurations, entanglements, and relaxation dynamics at the interfacial regions. By comparing grafted and nongrafted polymer nanocomposite systems based on poly(methyl methacrylate) and silica, we show that the distribution of relaxation times exhibits both commonly reported slower mobility and faster modes that depend on the nature of the interfacial zone, matrix molecular weight, and loading level of nanomaterials. These findings are derived from studies using broadband dielectric spectroscopy (BDS) and differential scanning calorimetry (DSC) to probe molecular and interfacial dynamics. By systematically examining nanocomposites based on nonfunctionalized “bare” Si nanoparticles (NPs) dispersed in PMMA matrices and on PMMA-grafted Si NPs (PMMA-g-NPs) in PMMA matrices, we probe the effects of interfacial interactions and confinement in each of these cases on the glass transition temperature, Tg, the mean time scales, and spectral shapes of the dielectric relaxation. The faster relaxation modes are attributed to the increasing importance of chain wetting and packing in the interfacial zones around nanofillers, especially in the polymer-grafted system. These insights are used to generate a unifying molecular framework that explains the enhancement in numerous macroscopic physical properties of polymer and polymer-grafted nanocomposites, which suits them for myriad applications.

Dynamics of poly[n]catenane melts.

Inspired by advances in the chemical synthesis of interlocking polymer architectures, extensive molecular dynamics simulations have been conducted to study the dynamical properties of poly[n]catenanes-polymers composed entirely of interlocking rings-in the melt state. Both the degree of polymerization (number of links) and the number of beads per ring are systematically varied, and the results are compared to linear and ring polymers. A simple Rouse-like model is presented, and its analytical solution suggests a decomposition of the dynamics into "ring-like" and "linear-like" regimes at short and long times, respectively. In agreement with this picture, multiple sub-diffusive regimes are observed in the monomer mean-squared-displacements even though interchain entanglement is not prevalent in the system. However, the Rouse-type model does not account for the topological effects of the mechanical bonds, which significantly alter the dynamics at intermediate length scales both within the rings and at the chain segment scales. The stress relaxation in the system is extremely rapid and may be conveniently separated into ring-like and linear-like contributions, again in agreement with the Rouse picture. However, the viscosity has a non-monotonic dependence on the ring size for long chains, which disagrees strongly with theoretical predictions. This unexpected observation cannot be explained in terms of chain disentanglement and is inconsistent with other measures of polymer relaxation. Possible mechanisms for this behavior are proposed and implications for materials design are discussed.

Creep-Relaxation Modeling of HDPE and Polyvinyl Chloride Bolted Flange Joints

AbstractSimilar to many polymer materials, high-density polyethylene (HDPE) and polyvinyl chloride (PVC) show a clear creep behavior, the rate of which is influenced by temperature, load, and time. Most bolted flange joints undergo relaxation under compression, which is caused by the creep of the material. However, the creep property of the two polymers is different under tension and compression loading. Since the sealing capacity of a flanged gasketed joint is impacted by the amount of relaxation that takes place, it is important to properly address and predict the relaxation behavior due to flange creep under compression and thereby reducing the chances of leakage failure of HDPE and PVC bolted flange joints. The main objective of this study is to analyze the compressive creep behavior of HDPE and PVC flanges under normal operating conditions. This is achieved by developing a respective creep model for the two materials, based on their short-term experimental creep test data. Both numerical and experimental simulations of the polymeric flange relaxation behavior are conducted on an NPS 3 class 150 bolted flange joint of dissimilar materials, where one of the flanges is made of HDPE or PVC material and the other one is made of steel SA105. The study also provides a clear picture on how the compression creep data of ring specimen may be utilized for predicating the flange bolt load relaxation over time at the operating temperatures.

The chain dis-entanglement effect of polyhedral oligomeric silsesquioxanes (POSS) on ultra-high molecular weight polyethylene (UHMWPE)

The nanoparticles small enough can significantly altered segmental dynamic and chain relaxation of polymer. The viscoelastic properties of ultrahigh molecular weight polyethylene (UHMWPE) blended with polyhedral oligomeric silsesquioxanes (POSS) was investigated in detail. A reduced viscosity of UHWMPE/Octamethyl- POSS was observed. The mechanism of viscosity reduction was studied from the view of disentanglement effect. Dynamic mechanical analysis (DMA) indicated that the pseudoequilibrium modulus (GN0) of UHMWPE/POSS (100/0.5) blend in the rubbery plateau was much lower than that of UHMWPE. Accordingly, the calculated entanglement density (Me) of UHMWPE/POSS blend was smaller than that of pure UHMWPE. Further reduction in glass transition temperature (Tg) was observed by the differential scanning calorimeter (DSC). Additionally, isothermal annealing was conducted on UHWMPE using differential fast scanning chip calorimetry (Flash-DSC) firstly. Two melting peaks of the sample were observed after isothermal melt-crystallization and the data were analyzed using the modified Arrhenius equation. The sample UHWMPE/POSS showed a lower melting active energy than pure UHWMPE, indicating the entanglement level of UHMWPE decreased and chain segment activity improved with addition of a small amount of POSS.

Hydrodynamics of polymers in an active bath.

The conformational and dynamical properties of active polymers in solution are determined by the nature of the activity. Here, the behavior of polymers with self-propelled, active Brownian particle-type monomers differs qualitatively from that of polymers with monomers driven externally by colored-noise forces. We present simulation and theoretical results for polymers in solution in the presence of external active noise. In simulations, a semiflexible bead-spring chain is considered, in analytical calculations, a continuous linear wormlike chain. Activity is taken into account by independent monomer or site velocities, with orientations changing in a diffusive manner. In simulations, hydrodynamic interactions (HIs) are taken into account by the Rotne-Prager-Yamakawa tensor or by an implementation of the active polymer in the multiparticle-collision-dynamics approach for fluids. To arrive at an analytical solution, the preaveraged Oseen tensor is employed. The active process implies a dependence of the stationary-state properties on HIs via the polymer relaxation times. With increasing activity, HIs lead to an enhanced swelling of flexible polymers, and the conformational properties differ substantially from those of polymers with self-propelled monomers in the presence of HIs, or free-draining polymers. The polymer mean-square displacement is enhanced by HIs. Over a wide range of timescales, hydrodynamics leads to a subdiffusive regime of the site mean-square displacement for flexible active polymers, with an exponent of 5/7, larger than that of the Rouse (1/2) and Zimm (2/3) models of passive polymers.

Evaluation of solute diffusion and polymer relaxation in cross-linked hyaluronic acid hydrogels: experimental measurement and relaxation modeling

Evaluation of transport properties of a drug in a hydrogel matrix is of engineering importance in the assessment of drug delivery systems. Water sorption and solute release are the two important aspects that determine the transport of water/solute in a hydrogel. A novel custom-made diffusion cell is used to examine the transport properties in the hydrogels by chemically cross-linking hyaluronic acid in various alkaline solutions at different cross-linker-to-polymer ratios. The tracer diffusion coefficient in the swollen hydrogel matrix in its rubbery state is estimated using a custom-made diffusional cell. The release kinetics is followed at perfect sink conditions, which transform from a glassy polymer dry membrane state to a swollen rubbery gel state. It is shown that the diffusion of solvent (water) through the hydrogel is case II transport, while the diffusion through the swollen hydrogel is case I (Fickian). The diffusion coefficient is proved to be independent of mesh size and pH of the initial solution. However, the release kinetics is influenced by the diffusion of solute and the relaxation of the polymer in hydrogel. The relaxation coefficient is a function of alkalinity in the solution with which the gel is being made. The contribution of relaxation to the transport during solvent sorption and solute release is found to be similar.

Influence of the α-relaxation on the high-velocity stretchability of isotactic polypropylene

The influence of the molecular weight (MW) of isotactic polypropylene (iPP) on the activation energy of the α-transition (EAα) and the stretching behaviour was investigated and correlations drawn. Mechanical relaxations in polyolefins are related to the mobility of polymer chains. The temperature of the α-transition in polyolefins increases with test frequency and draw ratio. Furthermore, the α-transition (i.e. intracrystalline chain dynamics) in polyolefins is related to thermally activated molecular motions, and thus a relationship between EAα, crystal growth, and plastic deformation exists. Stretched films and tapes of synthetic polymers are important in industrial packaging applications such as heavy duty BigBags or weaves. Many studies investigated either stretching or mechanical relaxations of semi-crystalline polymers, however, reports on direct correlations between EAα of polyolefins and their stretching behaviour are scarce. Furthermore, different DMTA-modes and sample preparation methods have not been compared and correlated yet. In this study, correlations between EAα of iPP-grades with different MW relevant for the entire processing range and their stretchability were investigated. Stretchability as well as mechanical properties and crystallinity of stretched tapes were highest for iPP-grades with a medium MW (346–360 kg/mol), while they were lower for low (218 kg/mol) and high MW (610 kg/mol), respectively. Ultimately, a linear relationship between EAα and stretchability was found for different iPP-grades for which a lower EAα resulted in higher stretchability, which correlated with higher crystallinities and mechanical properties of stretched tapes. Results obtained for iPP were also confirmed for low density (PE-LD) and high density (PE-HD) polyethylene. In addition, the impact of DMTA-mode (tension, torsion, and 3-point-bending) and sample preparation method (extruded tapes, compression moulded, and injection moulded specimen) for DMTA-measurements was evaluated.