Crystalline Polyethylene Research Articles

Influence of gas penetrans on polyethylene crystallinity observed by low field NMR

Polyethylene (PE) has a broad range of applications requiring rather different grades of used material differing also by their inner structure. PE inner structure contains two easily distinguishable phases: crystalline and amorphous. In this paper, we present a simple method of measurement of crystallinity (crystal content in sample) using low-field nuclear magnetic resonance. Moreover, we measured the crystallinity under different pressures of organic penetrant in order to observe sorption influence on inner PE structure. We confirm the broadly accepted fact that the penetrant sorbs into the amorphous phase. However, our results, measured at 35 °C, show that also the crystal phase is influenced by the sorption and with increasing pressure of organic penetrant (and so with increasing penetrated amount) the crystallinity of the sample decreases. We performed polymer-gas equilibrium measurements in ethylene and propylene environment to simulate catalytic polymerization conditions. We observed decrease in the crystallinity up to 9.5% at 30 bar ethylene pressure and 6.2% decrease at 11 bar propylene pressure. We propose, that the sorption process, even when induced by low soluble ethylene, decreases the crystallinity of the PE by various mechanisms.

High-Performance Polyethylene-Ionomer-Based Thermoplastic Elastomers Exhibiting Counteranion-Mediated Mechanical Properties

Because of their superior mechanical properties, excellent processability, reusability, and recyclability, thermoplastic elastomers (TPEs) have attracted considerable research attention. For random polyolefin-based TPEs, because the high crystallinity contributes to the high strength while decreasing the elastic recovery, the management of the tradeoff between the strength and stretchability is a critical challenge. Therefore, in this study, an elastomer was prepared based on a dual-cross-linking strategy by combining physical cross-links originating from polyolefin crystallinity and dynamic ionic cross-linking to resolve the tradeoff between the tensile strength and elastic recovery. First, ethylene/5-iodomethyl-2-norbornene/1-hexene terpolymers were synthesized with reactive iodine atoms, and the active sites were then transformed into a series of imidazolium-based ionomers bearing methane sulfonate (CH3SO3–), trifluoromethanesulfonate (CF3SO3–), or bis(trifluoromethane)sulfonimide (Tf2N–) counteranions via ionization and ion exchange. The interaction intensities between counteranions and imidazolium ions varied depending on the counteranion type. The ionomers containing CH3SO3– showed the highest tensile strength of up to 13.7 MPa, and those containing Tf2N– presented a favorable strain-at-break of up to 624%. The tensile properties were modulated over a broad range by changing the counteranion type and content. Moreover, because cross-links were generated by both ionic interactions and polyethylene crystallinity, the ionomers displayed excellent elastic recovery of up to 96%.

Influence of Functionalization on the Crystallinity and Basic Thermodynamic Properties of Polyethylene

Polymer functionalization, the grafting of functional groups onto polymer chains with strong intermolecular interactions, is a promising approach currently being explored to improve the recyclability and field use properties of commercially important polymeric materials. The mechanical properties of polyethylene (PE) are closely tied to the degree of crystallinity, which is expected to be influenced by polymer functionalization. We perform atomistic molecular dynamics (MD) simulations to study the effect of the functional groups on the change of the degree of crystallinity, as well as thermodynamical and local mechanical properties of a linear PE melt. In particular, we consider ester and amide groups as model polar functional groups. In both of these functionalized PE materials, we observe the densification and suppression of crystallization for functionalized PEs in the melt. Our simulation findings inform on the potential use of functionalization of PE as an approach to improve the recyclability of petroleum-based polymer materials.

Sewage sludge induces changes in the surface chemistry and crystallinity of polylactic acid and polyethylene films

Plastic pollution is a major threat facing our environment. To understand the full effects, we must first characterize how plastics break down in environmental systems. Heretofore, there has been little work examining how exposure to sewage sludge facilitates the degradation of plastics, particularly of plastics that have been previously weathered. Herein, we characterize how the crystallinity, surface chemistry, and morphology of polylactic acid (PLA) and polyethylene (PE) films change due to sludge exposure. In this work, sludge-induced changes in carbonyl index were found to depend on the level of prior exposure to ultraviolet (UV) irradiation. The carbonyl indices of un-irradiated films increased while those of UV-aged films decreased after 35 days of sludge exposure. In addition, the carbon‑oxygen and hydroxyl bond indices of PE films increased with sludge exposure, suggesting the surface oxidation of PE. As for PLA, crystallinity was found to increase with sludge exposure, consistent with a chain scission mechanism. This work will help to predict the behavior of plastic films after transfer from wastewater to sewage sludge.

Formation of Size-Controllable Tetragonal Nanoprisms by Crystallization-Directed Ionic Self-Assembly of Anionic Porphyrin and PEO-Containing Triblock Cationic Copolymer.

The creation of anisotropic nanostructures with precise size control is desirable for new properties and functions, but it is challenging for ionic self-assembly (ISA) because of the non-directional electrostatic interactions. Herein, the formation of size-controllable tetragonal nanoprisms is reported via crystallization-directed ionic self-assembly (CDISA) through evaporating a micellar solution on solid substrates. First, ISA is designed with a crystalline polyethylene oxide (PEO) containing cationic polymer poly(2-(2-guanidinoethoxy)ethyl methacrylate)-b-poly(ethyleneoxide)-b-poly(2-(2-guanidinoethoxy)-ethylmethacrylate) (PGn -PEO230 -PGn ) and an anionic 5,10,15,20-Tetrakis(4-sulfonatophenyl) porphyrin (TPPS) to form micelles in aqueous solution. The PG segments binds excessive TPPS with amplenet chargeto form hydrophilic corona, while the PEO segments are unprecedentedly dehydrated and tightly packed into cores. Upon naturally drying the micellar solution on a silicon wafer, PEO crystallizationdirects the micelles to aggregate into square nanoplates, which are further connected to nanoprisms. Length and width of the nanoprisms can be facilely tuned by varying the initial concentration. In this hierarchical process, the aqueous self-assembly is prerequisite and the water evaporation rate is crucial for the formation of nanostructures, which provides multiple factors for morphology regulating. Such precise size-control strategy is highly expected to provide a new vision for the design of advanced materials with size controllable anisotropic nanostructures.

Nonmonotonic Variation of Rutting Resistance and Fatigue Life for Polyethylene Modified Bitumen with Different Carbon Black Loading

Polyethylene (PE) and carbon black (CB) were premixed in this study for bitumen modification. The service performance of PE/CB-modified bitumen (PMB) was mainly explored by multiple stress creep recovery (MSCR) and linear amplitude sweep (LAS) tests to reveal the rutting resistance and fatigue life, respectively. Low-temperature properties were evaluated by glass transition temperature (Tg) measured by dynamic mechanical analysis (DMA). X-ray diffraction (XRD) results suggested that the crystalline structure of PE was almost the same regardless of different CB loading additions. It was found that the both rutting resistance and fatigue life of PMBs showed nonmonotonic variation with CB loading. The mechanism for this variation was closely related to the microstructure induced by phase separation, CB nanoparticle aggregation and PE crystallinity. As revealed by optical and atomic force microscopy, two different phase structures, network and droplet-matrix structure, can be formed in PMBs when the CB loading changes. In particular, a double percolated network structure can be formed, consisting of a PE-rich network in the bitumen-matrix and CB nanoparticle network within a PE-rich phase. With the presence of this structure, the rutting resistance and fatigue life of PMB can be significantly improved.

Dynamics of Phonon-Assisted Holes Trapping and Transport over Chemical Defects in Polyethylene.

Charge trapping and transport over chemical defects in polyethylene have significant impacts on its electrical and dielectric properties. However, the dynamics of this phenomenon and its underlying mechanisms remain unclear. To understand this fundamental aspect, we conducted a time-domain ab initio nonadiabatic molecular dynamics study of phonon-assisted holes dynamics in polyethylene over C═O and C-OH defect states. Our results suggest that the hole transfer and energy fluctuations substantially depend on temperature and local morphology. When the temperature decreases from 300 to 100 K, the hole transfer efficiency and the energy fluctuations are severely suppressed due to the weakened interactions between holes and phonons. Furthermore, amorphous polyethylene exhibits a severe suppression of the hole transfer process compared to crystalline polyethylene. An explanation for the influence of morphology on the hole transfer process can be found in the differences in the hole-phonon coupling and the electronic coupling between two chemical defect states in crystalline and amorphous polyethylene. Advancing the fundamental understanding of the dynamics of hole transfer over chemical effects in polymers is a key to improving their insulating properties for the next-generation high-voltage cables.

Calculation of the degree of crystallinity of HDPE/GNPs nanocomposites by using various experimental techniques: a comparative study

This work is a comparative study of four different techniques to determine the crystallinity of high-density polyethylene (HDPE) nanocomposites filled with different diameter sizes (5, 15 and 25 μm) of graphene nanoplatelets (GNPs) at various amounts (0.5–5 wt%). The structure of HDPE/GNPs nanocomposites was extensively studied by using different experimental methods, such as X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. To further provide a complete comparison, differential scanning calorimetry measurements were utilized to calculate the crystallinity values, while temperature-modulated DSC was employed to investigate the possible mechanism of the different crystalline structures. It was found that these methods can be used to estimate the crystallinity, but the sample parameters and experimental conditions must be taken into consideration. All the techniques showed that the crystallinity depends on GNPs size and content. The distance between dispersed platelets was substantial at low concentrations of GNPs, making it comparatively easy for additional nucleation sites to incorporate the polymer matrix, and the crystal nucleus was simply formed. However, at high concentrations of GNPs, the diffusion of polymer chains to the growing crystallites was hindered by large GNPs particles, despite the formation of additional nucleation sites.

Photocatalytic solid-phase degradation of polyethylene with fluoride-doped titania under low consumption ultraviolet radiation

Photodegradation of plastic in solid-phase requires the polymer to be composited with an efficient photocatalyst. We report herein the successful synthesis and characterization of fluoride-doped-TiO2 and its applicability, for the first time, on solid-phase photodegradation of polyethylene films. Nearly half weight loss of polyethylene, containing only 2% of the photocatalyst, is eliminated after three weeks of ultraviolet A radiation using a low consumption light emitting diode lamp, defeating previously reported data. The half-life time of the plastic was around 3 weeks, highlighting the viability of this process for real applications. Results were compared to raw PE and PE composite with well-known TiO2, resulting in, respectively, 0 and 26% of weight loss. The degradation process was monitored by optical microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared and X-ray photoelectron spectroscopy, which revealed the formation of plastic cracks, loss of polyethylene crystallinity and thus stability, the oxidation of C–H bonds and the oxidized state of the surface compounds during photodegradation. The obtained results open a path for the future production of cleaner and self-photodegradable plastics, where the photocatalyst would be introduced in all the manufactured plastics, making possible the quicker photodegradation of the plastics that end up on the environment and the plastics reaching wastewater treatment plants.

Evaluation of crystallinity, thermal, mechanical and morphological features of high density polyethylene composites reinforced with crosslinked semifluorinated acrylate polymer microspheres

This study mainly aims both to prepare well-shaped crosslinked 3,3,4,4,5,5,6,6,7,7,8,8,8 tridecafluorooctyl-4-(acrloyloxy) benzoate (ABCF13) polymer microspheres and to investigate the influences of the prepared microspheres addition on the crystallinity, thermal, mechanical and morphological features of high density polyethylene (HDPE). The suspension polymerization method was used for the production of well-defined microspheres and, the content of the microspheres varied from 1.0% to 10.0% in the composites. The characterization of crosslinked poly(ABCF13) microsphere-loaded HDPE composites were performed via powder X-ray diffraction, differential scanning calorimeter, universal mechanical (tensile and impact) testers and scanning electron microscope (SEM) techniques. According to the experimental findings, a and b unit cell parameters increased initially and reached maxima with the sample including 5.0% microsphere, which were followed by dramatic decreases, while c parameter remained relatively unchanged. Thermal analysis also showed that the melting temperature of HDPE reduced with the initial loading of the microspheres, then stayed at a plateau value of about 129°C due to the formation of lattice distortions, generation of microstructural disorders and the defects in the crystal structures. The mechanical test results revealed that there existed considerable improvements in tensile strength, modulus and impact strength. The maximum tensile strength 25.66 MPa, elastic modulus 499.30 MPa and maximum absorbed energy in the impact test 26.84 kJ/m2 (29%, 42% and 41% improvement, respectively) were achieved with the blend involving 5.0% microsphere. After the maxima, the mechanical characters depicted weakening trend as the microsphere content increased in the matrix. The SEM analyses revealed that although there existed fibrillar formations in all samples, the extensions decreased with the increase of the microsphere content. While ductile behavior was observed with the formation of long-bulky extensions at low contents, brittleness started to prevail at high contents with some short and thin fibrils.

PETase gets hot

Few enzymes thus far can effectively deconstruct real-world plastic products comprising highly crystalline polyethylene terephthalate (PET). Recently in Nature Catalysis , Bell et al. developed a directed evolution platform for PETase engineering, generating a robust, thermally stable biocatalyst, HotPETase, capable of decomposing untreated PET samples (up to ∼41% crystallinity). Few enzymes thus far can effectively deconstruct real-world plastic products comprising highly crystalline polyethylene terephthalate (PET). Recently in Nature Catalysis , Bell et al. developed a directed evolution platform for PETase engineering, generating a robust, thermally stable biocatalyst, HotPETase, capable of decomposing untreated PET samples (up to ∼41% crystallinity).

Coarse-grained simulation to study the thermal conductivity of crystalline polyethylene

<p indent="0mm">As one of the most used polymer material, polyethylene (PE) has excellent mechanical and processing properties. However, the low thermal conductivity limits the application of polyethylene in field of electronic devices, which needs good thermal conductivity for heat management. However, recent studies report excellent thermal conductivity for PE fibres. It should be very interesting to check if it is possible to convert PE from low thermal conductivity materials to high ones. In this study, in order to make a deep understand on thermal conductivity of PE material, a coarse-grained model of crystalline PE was constructed, and molecular dynamics simulation methods were used to explore the effect of crystallization on the intrinsic thermal conductivity of PE. First, Boltzmann inversion method was applied to build the coarse-grained model of PE, which is suitable to mimic physical behaviours of PE material with varied crystalline degrees. The simulation data such as the bond distribution function, angular distribution function, and radial distribution function of the coarse-grained model are found consistent with those from all-atom model. Furthermore, various physical data calculated from coarse-grained model are compared with those from reported experimental studies, such as glass transition temperature, thermal expansion coefficient, mean square radius of gyration, diffusion coefficient and thermal conductivity. All above physical data of coarse-grained model fit well with those from literatures. It means our coarse-grained model is readily to mimic PE materials, especially in field of thermal properties. For example, the curve of thermal conductivities of a single PE chain varied along with chain length calculated from our coarse-grained model lies between results from previous theoretic predictions. Second, the coarse-grained PE model with various crystalline degree and same crystalline degree of varied crystalline particles sizes are systematically investigated. We paid much attention on effect of stretching on thermal conductivity of PE models, because stretching is an efficient way to alter alignment state of PE chains. The results show that thermal conductivity of the PE model increases along with the increasing of crystalline degree. During stretching, the PE models with higher crystalline degree are easily reconfigured to align chains along the stretching direction, which is the thermal transporting direction, that in turn causes an obviously increasing for thermal conductivity. At the same crystalline degree, PE model with larger crystalline particle size is easier to form a high thermal conductivity system under stretching comparing with those with small crystalline particle sizes. Order parameters represent alignment of PE chains are calculated to analysize this observation. To conclude, the coarse-grained PE model established in this paper can be used to study the thermal conductivity of complex crystalline systems. The physical properties calculated from coarse-grained PE model are found to fit well with experimental and theoretic data of PE materials. Our simulation explores the dependence of thermal conductivity on crystalline state of PE material, and provides a theoretical basis for designing and manufacturing the intrinsic high thermal conductivity polymer materials. The coarse-grained model is thought to be able to explore mechanical properties of crystalline PE materials in the future.

A Ziegler-type spherical cap model reveals early stage ethylene polymerization growth versus catalyst fragmentation relationships

Polyolefin catalysts are characterized by their hierarchically complex nature, which complicates studies on the interplay between the catalyst and formed polymer phases. Here, the missing link in the morphology gap between planar model systems and industrially relevant spherical catalyst particles is introduced through the use of a spherical cap Ziegler-type catalyst model system for the polymerization of ethylene. More specifically, a moisture-stable LaOCl framework with enhanced imaging contrast has been designed to support the TiCl4 pre-active site, which could mimic the behaviour of the highly hygroscopic and industrially used MgCl2 framework. As a function of polymerization time, the fragmentation behaviour of the LaOCl framework changed from a mixture of the shrinking core (i.e., peeling off small polyethylene fragments at the surface) and continuous bisection (i.e., internal cleavage of the framework) into dominantly a continuous bisection model, which is linked to the evolution of the estimated polyethylene volume and the fraction of crystalline polyethylene formed. The combination of the spherical cap model system and the used advanced micro-spectroscopy toolbox, opens the route for high-throughput screening of catalyst functions with industrially relevant morphologies on the nano-scale.

Influence of crystallinity on wear behavior of ultrahigh molecular weight polyethylene and the wear mechanism

Abstract In this paper, the crystallinity (X c) of ultra-high molecular weight polyethylene (UHMWPE) parts was adjusted within a wide range from 40 to 60%, and the influence of X c on wear performance and its relevant mechanism were surveyed. The volume wear rate of UHMWPE parts continuously decreased with increasing X c. Structural characterization revealed that the closely packing crystalline structure composed of high X c and large-size lamellae improves resistance to plastic deformation, which is responsible for excellent anti-wear performance. The efficiency of improving the wear resistance by high X c is comparable with the traditional method of irradiation-induced crosslink. But the latter may severely harm the anti-oxidation capacity. So, increasing X c is a promising candidate to develop high-performance UHMWPE materials with superior wear resistance.

The effect of peroxide cross-linking on the thermal conductivity and crystallinity of low-density polyethylene

In this work, the thermal conductivity of a series of low-density polyethylene (LDPE) with different degrees of cross-linking was measured by the transient hot-wire method at different temperatures. It was found that the thermal conductivity of LDPE samples with different degrees of cross-linking decreased smoothly with increasing temperature at temperatures ranging from ‐20 to 80°C. The higher the degree of cross-linking, the smaller the negative temperature dependence of the cross-linked LDPE samples. The decrease of negative temperature dependence of LDPE was explained by the thermal vibration of molecular chains. Meanwhile, the crystallinity and melting point of a series of LDPE samples with different degrees of cross-linking were determined by differential scanning calorimetry (DSC), and the crystallization process of LDPE samples with different degrees of cross-linking was investigated using the Jeziorny method with a modification of the Avrami equation. The results show that the thermal conductivity of cross-linked LDPE is directly proportional to the crystallinity and inversely proportional to the gel content. This work provides a basis for the future design of semi-crystalline polymers with no temperature dependence of thermal conductivity.

Effect of freeze-thaw cycle aging and high-temperature oxidation aging on the sorption of atrazine by microplastics

This study aims to better understand the aging characteristics of microplastics in the environment and the influence of aging microplastics on the migration and transformation of organic pollutants. In this study, polyvinyl chloride (PVC) and polyethylene (PE) were chosen as research objects, and the effects of two aging methods (freeze-thaw cycle aging and high-temperature oxidation aging) on their surface properties and atrazine (ATZ) sorption were investigated. The crystallinity of PE increased after freeze-thaw cycling and decreased after high-temperature oxidation. The freeze-thaw cycle destroys the amorphous region of PE, reducing the micropores on the PE surface and decreasing the ATZ adsorbed by PE. Although aging had no significant effect on the surface structure of PVC, it caused new oxygen-containing functional groups to be produced on the PVC surface, which reduced the ATZ adsorption capacity. These results show that the two aging modes change the surface properties of PVC and PE, thus affecting the sorption mechanism of ATZ, and provide a theoretical premise for the natural behavior and ecological chance assessment of ATZ in the presence of microplastics.

Modelling the Photodegradation of Marine Microplastics by Means of Infrared Spectrometry and Chemometric Techniques

This work investigated the structural and chemical changes of plastics undergoing accelerated ageing upon irradiation that simulated the ultraviolet component of solar radiation for a five-year period. The plastics selected were polyethylene (PE) and polypropylene (PP) microplastic debris sampled from a sandy beach as well as pure pellets and fragments of objects made of the same polymers. We recorded Fourier Transform Infrared (FTIR) spectra at prescribed intervals during the irradiation procedure. The spectra were used to study the evolution of the absorption peaks usually associated with the environmental ageing of polyolefins, namely the peaks of hydroxyl and carbonyl stretching, the peaks relating to the presence of double bonds, and those associated with the crystallinity of PE and the tacticity of PP. The results showed that none of the usual degradation indexes followed a clear trend with increasing exposure and that the evolution of absorption peaks was not consistent among different fragments. We used the Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) method to process the whole information contained in the FTIR spectra in response to the chemical changes occurring during photochemical ageing. The results showed that the FTIR spectra contained sufficient information to cluster samples according to the irradiation received. Variable Importance of the Projection (VIP) analyses showed that the information for discriminating among different exposures was mainly contained in the absorption peaks corresponding to the hydroxyl and carbonyl stretching absorptions. The chemometric models had large determination coefficients, despite the large number of variables involved and could be applied to assess the environmental fate of plastics under environmental stressors.

Ordered Nanostructures in Thin Films of Precise Ion-Containing Multiblock Copolymers.

We demonstrate that ionic functionality in a multiblock architecture produces highly ordered and sub-3 nm nanostructures in thin films, including bicontinuous double gyroids. At 40 °C, precise ion-containing multiblock copolymers of poly(ethylene-b-lithium sulfosuccinate ester)n (PESxLi, x = 12 or 18) exhibit layered ionic assemblies parallel to the substrate. These ionic layers are separated by crystalline polyethylene blocks with the polymer backbones perpendicular to the substrate. Notably, above the melting temperature (Tm) of the polyethylene blocks, layered PES18Li thin films transform into a highly oriented double-gyroid morphology with the (211) plane (d211 = 2.5 nm) aligned parallel to the substrate. The cubic lattice parameter (agyr) of the double gyroid is 6.1 nm. Upon heating further above Tm, the double-gyroid morphology in PES18Li transitions into hexagonally packed cylinders with cylinders parallel to the substrate. These layered, double-gyroid, and cylinder nanostructures form epitaxially and spontaneously without secondary treatment, such as interfacial layers and solvent vapor annealing. When the film thickness is less than ∼3agyr, double gyroids and cylinders coexist due to the increased confinement. For PES12Li above Tm, the layered ionic assemblies simply transform into disordered morphology. Given the chemical tunability of ion-functionalized multiblock copolymers, this study reveals a versatile pathway to fabricating ordered nanostructures in thin films.

Empirical Determination of the Pressure-Temperature Phase Diagram of Polyethylene Based on the Pressure-Volume-Temperature-Entropy Gibbs Free Energy Equation of State

The pressure-temperature (P-T) phase diagram for polyethylene (PE) was calculated based on the empirical Gibbs free energy (G) equation of state, GFE-Eos, for the crystalline PE (crys-PE) and the amorphous PE (amor-PE) where the GFE-Eos consists of variables such as the pressure (PG ), volume (VG ), temperature (TG ), and entropy (SG ) which satisfy the condition that the G is constant. The GFE-Eos for the crys-PE and the amor-PE can be expressed by three dimensional (T G-P G-G) planes, from which the melting temperature (Tm ) line was evaluated. The thermodynamic quantities of V m and S m for the crys-PE and amor-PE at Tm and their discontinuous changes, and along the melting line were evaluated and discussed based on the Clapeyron equation for the phase transition.

Anhydrous Proton Transport within Phosphonic Acid Layers in Monodisperse Telechelic Polyethylenes

Polymers bearing phosphonic acid groups have been proposed as anhydrous proton-conducting membranes at elevated operating temperatures for applications in fuel cells. However, the synthesis of phosphonated polymers and the control over the nanostructure of such polymers is challenging. Here, we report the straightforward synthesis of phosphonic acid-terminated, long-chain aliphatic materials with precisely 26 and 48 carbon atoms (C26PA2 and C48PA2). These materials combine the structuring ability of monodisperse polyethylenes with the ability of phosphonic acid groups to form strong hydrogen-bonding networks. Anhydride formation is absent so that charge carrier loss by a condensation reaction is avoided even at elevated temperatures. Below the melting temperature (Tm), both materials exhibit a crystalline polyethylene backbone and a layered morphology with planar phosphonic acid aggregates separated by 29 and 55 Å for C26PA2 and C48PA2, respectively. Above Tm, the amorphous polyethylene (PE) segments coexist with the layered aggregates. This phenomenon is especially pronounced for the C26PA2 and is identified as a thermotropic smectic liquid crystalline phase. Under these conditions, an extraordinarily high correlation length (940 Å) along the layer normal is observed, demonstrating the strength of the hydrogen bond network formed by the phosphonic acid groups. The proton conductivity in both materials in the absence of water reaches 10-4 S/cm at 150 °C. These new precise phosphonic acid-based materials illustrate the importance of controlling the chemistry to form self-assembled nanoscale aggregates that facilitate rapid proton conductivity.