High-density Polyethylene Samples Research Articles

Polyethylene Incorporating Diels-Alder Comonomers: A "Trojan Horse" Strategy for Chemically Recyclable Polyolefins.

Polyolefins with periodic unsaturation in the backbone chain are sought after for synthesizing chemically recyclable polymers or telechelic polyolefin macromonomers. Here we introduce a bottom-up synthesis of unsaturated high-density polyethylene (HDPE) via copolymerization of ethylene with dimethyl 7-oxabicyclo[2.2.1]hepta-2,5-diene-3,5-dicarboxylate followed by post-polymerization retro-Diels-Alder to unveil hidden double bonds in the polymer backbone. The incorporation of this "Trojan Horse" comonomer was varied and a series of unsaturated HDPE polymers with block lengths of 1.2, 1.9, and 3.5 kDa between double bonds was synthesized. Cross metathesis of unsaturated HDPE samples with 2-hydroxyethyl acrylate yielded telechelic ester terminated PE macromonomers suitable for the preparation of ester-linked PE. These materials were depolymerized and repolymerized, making them suitable candidates for chemical recycling. The ester-linked PE displayed thermal and mechanical properties comparable to commercial HDPE.

Polyethylene Incorporating Diels–Alder Comonomers: A “Trojan Horse” Strategy for Chemically Recyclable Polyolefins

AbstractPolyolefins with periodic unsaturation in the backbone chain are sought after for synthesizing chemically recyclable polymers or telechelic polyolefin macromonomers. Here we introduce a bottom‐up synthesis of unsaturated high‐density polyethylene (HDPE) via copolymerization of ethylene with dimethyl 7‐oxabicyclo[2.2.1]hepta‐2,5‐diene‐3,5‐dicarboxylate followed by post‐polymerization retro‐Diels–Alder to unveil hidden double bonds in the polymer backbone. The incorporation of this “Trojan Horse” comonomer was varied and a series of unsaturated HDPE polymers with block lengths of 1.2, 1.9, and 3.5 kDa between double bonds was synthesized. Cross metathesis of unsaturated HDPE samples with 2‐hydroxyethyl acrylate yielded telechelic ester terminated PE macromonomers suitable for the preparation of ester‐linked PE. These materials were depolymerized and repolymerized, making them suitable candidates for chemical recycling. The ester‐linked PE displayed thermal and mechanical properties comparable to commercial HDPE.

Estimation Method of Molecular Weight of Polyethylene using Terahertz Spectroscopy

This paper uses terahertz (THz) spectroscopy for the first time as a simple method for estimating the molecular weight of a polymer across a very wide range. The viscosity average molecular weight (Mv) was measured and estimated as the molecular weight. Currently, to measure the Mv, a sample is dissolved in a solvent then measured its inherent viscosity. However, this procedure is complicated and time-consuming in practice. Additionally, as the molecular weight increases, the measurement accuracy decreases if Mv of a sample is above 3 million. Therefore, a new simple method is desired. A linear high-density polyethylene sample with an Mv range of 0.1 to 7.4 million was used. THz absorbance spectra of the samples were measured from 50 to 600 cm-1 (1.5 to 18 THz) then the multivariable analysis technique was applied. Consequently, a very high correlation coefficient (R2 ≈ 1) between the estimated and the measured Mv values were obtained across the range of the samples. This method is essential and suitable for industrial applications.

Cross-sectional microstructural analysis to evaluate the crack growth pattern of weathered marine plastics

Fragmentation of degraded plastics and release of smaller secondary microplastics is usually attributed to the growth of environmental stress cracks. Analysis of crack patterns derived from chemical degradation can be useful not only for assessing the cause of plastic fracture and evaluating the useful lifetime of a product, but it can also potentially provide valuable information on the generation of microplastics. However, the literature with respect to microplastics generation is generally limited to surface observations of polypropylene and polyethylene. Here, we used ion-beam milling to prepare cross-sections of fragments of 15 plastic products made from five commodity plastics (polypropylene, polyethylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate) that were collected at two beaches in Japan, and then we examined the microstructures of those cross-sections by means of scanning electron microscopy and energy dispersive X-ray spectroscopy. Crack growth in the depth direction was examined to provide insights into microplastic generation behavior. In all of the polypropylene samples, and some of the low-density polyethylene and polystyrene samples, cracks with a depth exceeding 100 μm from the sample surface were observed. Considering that crack growth causes fracture of degraded plastic and microplastic release, these observations suggest the release of sharp-edged microplastics from the crack fracture surface. In contrast, in the high-density polyethylene and polyvinyl chloride samples, crack growth was limited to within 20 μm of the sample surface, suggesting the release of irregularly shaped microplastics and additive particles. The present results suggest that the degradation behavior of plastic products in the depth direction is dependent on the type of plastic.

Effects of combined melt stretching and fast cooling fields on crystallization of high-density polyethylene

In many industrial processes, polymer melt undergoes complex flow-cooling environments before being solidified into the final products. Investigating polymer crystallization under processing conditions is a necessary step to predict and customize the structures and properties of semicrystalline polymers. Herein, the crystallization behavior of high-density polyethylene (HDPE) under combined melt stretching and fast cooling fields was studied through a homemade extensional rheometer. A series of HDPE samples were prepared by cooling the stretched melt at different cooling rates (0.02–220 °C/s) immediately after flow, or after waiting for different times of isothermal crystallization at 128 °C. Microstructural characterizations confirm four different structural states related to the evolution of shish-kebabs after melt stretching, namely generation of shish precursors, shish crystal growth, kebab lamellar growth, and perfection of shish-kebabs, which diversify greatly the structures and morphologies of the final solidified samples. By prolonging the isothermal crystallization time at high temperature, the fast cooling-induced lamellae keep decreasing in thickness. This supports the occurrence of molecular segregation caused by shish-kebabs growth at high temperature, which reduces the molecular weight of the remaining un-crystallized melt. In addition, quantitative analysis of crystalline orientation manifests that the lamellar growth during isothermal process takes strictly the shish as a template and adopts a high orientation, while the fast cooling-induced lamellae are only related to the chains conformation of un-crystallized melt prior to cooling. This work would be essential to advance the in-depth understanding on the actual industrial processing of semicrystalline polymeric materials.

Constructing a parallel aligned shish kebab structure of HDPE/BN composites: Toward improved two-way thermal conductivity and tensile strength

Inspired by the clam-shell structure of pearls, we fabricated thermally conductive high-density polyethylene (HDPE) reinforced by a 2D filler, boron nitride (BN). SEM images showed only lamellae randomly distributed in unshared HDPE samples, whereas a shish-kebab structure was introduced by utilizing an in-house designed rotational shear system. XRD results indicate the BN (002) plane is parallel to the sheared direction. Due to the interconnected shish-kebab structure and aligned BN (002) plane, the Vicat softening temperature was increased from 82.8 °C to 107.9 °C, demonstrating excellent heat resistance under high temperatures. An optimal thermal conductivity of 1.26 W/mK was found at 35 vol% BN loading with a tensile strength of 40 MPa. This work has utilized external force to manufacture HDPE/BN composites with effective thermal dissipation and higher service temperature. The excellent thermo-mechanical properties mean a longer service time and less replaced frequency of material under extreme operating conditions.

Replication Study of Molded Micro-Textured Samples Made of Ultra-High Molecular Weight Polyethylene for Medical Applications

In articular joint implants, polymeric inserts are usually exploited for on-contact sliding surfaces to guarantee low friction and wear, a high load-bearing capacity, impact strength and stiffness, and biocompatibility. Surface micro-structuring can drastically reduce friction and wear by promoting hydrostatic friction due to synovial fluid. Ultra-High Molecular Weight Polyethylene (UHMWPE) is a suitable material for these applications due to its strong chemical resistance, excellent resistance to stress, cracking, abrasion, and wear, and self-lubricating property. However, surface micro-texturing of UHMWPE is hardly achievable with the currently available processes. The present study investigates UHMWPE's micro-textured surface replication capability via injection molding, comparing the results with the more easily processable High-Density Polyethylene (HDPE). Four different micro-texture cavities were designed and fabricated on a steel mold by micro-EDM milling, and used for the experimental campaign. Complete samples were fabricated with both materials. Then, the mold and samples were geometrically characterized, considering the dimensions of the features and the texture layout. The replication analysis showed that HDPE samples present geometrical errors that span from 1% to 9% resulting in an average error of 4.3%. In comparison, the UHMWPE samples display a higher variability, although still acceptable, with percentage errors ranging from 2% to 31% and an average error of 11.4%.

Reversed thermal stability between stress-induced melting and recrystallized crystallites and original inclined ones in moderately stretched ultra high molecular weight polyethylene and high density polyethylene

The structural evolution of tensile stretched ultra high molecular weight polyethylene (UHMWPE) and high density polyethylene (HDPE) samples to an intermediate strain before the completion of fibrillation upon heating was investigated by means of small-angle X-ray scattering (SAXS) and wide angle X-ray diffraction techniques (WAXD). Six-point SAXS patterns illustrated the existence of two populations of lamellae, one at the inclined direction belonging to the original lamellae experienced deformation of slip processes and another at the tensile direction (meridional lamellae) which were newly formed ones due to fibrillation (stress induced melting-recrystallization). Surprisingly, the inclined lamellae exhibit better thermal stability compared to meridional lamellae in UHMWPE sample, whereas in the HDPE sample the situation is opposite. It turns out that this higher stability of original deformed lamellae at the inclined direction is due to the much higher number of tie chains and more stable entangled amorphous network in UHMWPE which minimizes the surface free energy of those lamellae during heating.

Identification of Microplastics Using a Custom Built Micro-Raman Spectrometer

Microplastics are plastic particles less than 5 mm in size but larger than 0.1 µm. Widespread microplastic pollution in aquatic and terrestrial environment is raising serious concern globally due to its detrimental impacts on living beings. This urge for the necessity of a sensitive analytical tool, which can facilitate reliable identification of microplastics. Micro-Raman spectroscopy enables molecular level structural details of samples and thus highly preferable for the identification of microplastics in water. Besides being a non-destructive technique enabling fast analysis, this technique requires minimal/no sample preparation. The present work demonstrates the performance of a custom built Micro-Raman spectrometer for the discrimination of various microplastics in water based samples. Micro- Raman analysis have been found quite successful in the identification of Polystyrene (PS), Polyethylene terephthalate (PET), High Density Poly ethylene (HDPE), Low Density Poly ethylene (LDPE) etc. The Micro-Raman spectral data have been capable enough for the discrimination of high-density polyethylene (HDPE,> 0.940 g/cm3) and low-density polyethylene (LDPE,< 0.930 g/cm3) microplastics, especially due to the variations in the C-H stretching vibrations (2825-2970 cm−1). The ratio of intensities of asymmetric CH2 stretching mode (2879 cm−1) and the symmetric CH2 stretching mode (2847 cm−1) are found to be higher for HDPE with respect to LDPE. Moreover, intensity variations were also observed for the antisymmetric and symmetric C-C stretching bands present at 1059 cm−1 and 1126 cm−1 respectively. The band at 1167 cm−1 arising from CH vibration have also shown an intensity enhancement in HDPE samples.

Study of the laser-material interaction for innovative hybrid structures: Thermo-mechanical characterization of polyethylene-based polymers

This study deals with the experimental analysis of the effects of laser radiation on semi-crystalline polyethylene-based polymers. This paper has been developed as basis for future development of an innovative joining system, based on laser technology, to produce hybrid structures consisting of metal and polymer parts. Several process monitoring techniques, such as mechanical tensile test, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), flat-top cylinder indentation test (FIMEC) and infrared analysis (FTIR) have been used to evaluate the thermo-mechanical properties of the tested materials, with the aim to identify the technological process window for the joining process. The investigation, focused on two thermoplastic samples in high density polyethylene (HDPE) and polyethylene terephthalate (PET), aimed to investigate any structural changes caused by the laser irradiation of the polymer materials. Results showed no degradation for PET material and only a minor oxidation effect for black high-density polyethylene (HDPE) sample. The achievements of this study are of crucial importance for the identification and setting of the optimal irradiation parameters during laser joining operations, thus avoiding ineffective heating or excessive degradation of the material.

Antibacterial efficiency of cadmium thin films deposited by the thermionic vacuum arc

In this study, thin films of the pure Cadmium (Cd) were deposited on glass and high-density polyethylene (HDPE) samples by the Thermionic Vacuum Arc (TVA) method. The structural and surface morphological properties of Cd thin-films were investigated using X-ray diffraction patterns (XRD), field emission scanning electron microscope (FE-SEM), and atomic force electron microscope (AFM). The water contact angle (WCA) was determined by a Krüss DSA100 model goniometer. The antibacterial activities of the Cd-coated and uncoated samples were investigated by direct-contact test and modified Kirby-Bauer test against Escherichia coli O157:H7 ATCC35150, Staphylococcus aureus ATCC6538P and Listeria innocua ATCC33090. Cd thin films deposited on both samples were found to be in crystalline form. The Crystallite size of the films deposited on glass and HDPE were calculated as 52.1 and 72.5 nm, respectively. The SEM and AFM depict the Cd films uniform distribution of grains. The root mean square (Rms) surface roughness of Cd thin film was found as 39.3 nm and 70.3 nm on glass and HDPE substrates, respectively. The WCA measurements showed the cadmium coatings increased the hydrophobicity of glass and HDPE samples. Direct-contact test showed both Cd-coated samples totally inhibited E. coli O157:H7 and L. innocua strains after 2-h of contact time. Modified Kirby-Bauer test indicated the Cd-coated HDPE samples showed the highest antibacterial activity against L. innocua however Cd films did not have any antibacterial activity for both samples against S. aureus.

Multiple kinetic processes of lamellar growth in crystallization of stretched lightly crosslinked polyethylene

The growth of polymer crystals is accompanied by the change of interior conditions as time evolves. Therefore, its underlying mechanism should be time-dependent. Here, we investigate the process of lamellar growth by measuring stretched lightly crosslinked high-density polyethylene samples with in situ small-angle X-ray scattering and wide-angle X-ray diffraction. Two analysis methods are used to track the lamellar radius. It is found that the lamellar growth sequentially undergoes three stages, i.e., the interface-controlled stage, the diffusion-controlled stage, and the crystal perfection stage through Ostwald ripening mechanism. The transition between the first and the second stages is related to the competition between the diffusion of chains towards the growth surface and the consumption of chains at the surface in the ideal interfacial kinetics. This transition is significantly affected by the yielding of the sample. The second transition corresponds to the depletion of crystallizable chains, and is directly reflected by the decrease of the polydispersity of lamella radius. These results highlight the importance of the chain consumption in determining the mechanism of lamellar growth.

Gas permeameter for polymers and nanocomposites: a new equipment

Information on the gas transport coefficients in the permeation of homogeneous semipermeable materials such as semicrystalline polymers under extreme pressures and temperatures is rarely found in the literature. Therefore, the objective of this work is to showcase innovation regarding the accuracy and usability of the medium pressure and temperature gas permeameter suitable for polymeric and polymeric nanocomposite plates built by the authors, which was tested with nitrogen at 1 MPa and 69 °C (342.15 K) permeating pure high density polyethylene samples (HDPE) and HDPE samples with added nanoclay, redoing the tests published in a previous work on the subject. The results were compared against data obtained previously and information present in the literature, validating the permeameter presented in this work, which is capable of analyzing gas permeability under the described conditions with greater accuracy and ease of operation than the previous model for the values of the transport coefficients of nitrogen permeating HDPE, demonstrating that the implemented improvements and advances were adequate, allowing the measurement of the transport properties of gases permeating polymeric and nanocomposite plates, necessary information for the design of risers for the transportation of oil and natural gas, for example.

Melt flow ratio: A way to identify the type of polyethylene

Melt flow ratio (MFR or I21/I2) was measured for dozens of polyethylene (PE) in the melt index (MI or I2) range of 1–10 for various types of PE. I21/I2 for samples of linear low density polyethylene (LLD) polymerized by a Ziegler-Natta catalyst (ZN-LLD) lie near I21/I2 = 25, whereas those for specimens of metallocene linear low density polyethylene (m-LLD) scatter close to I21/I2 = 18. The plot of I21/I2 vs I2 for LLD showed that I21/I2 is almost independent on molecular weight and short chain branching (SCB), but strongly dependent on molecular weight distribution (MWD). The broader MWD, the larger I21/I2. This rule basically holds for both low density polyethylene (LDPE) and high density polyethylene (HDPE). However, at a certain I2 around 6 a discontinuous jump of I21/I2 for HDPE samples exits, where I21/I2 for samples of I2 less than 6 lie near those of LDPE and I21/I2 for ones having I2 bigger than 6 disperse close to those of ZN-LLD. In addition, bimodal PE or PE with long chain branching has a bigger I21/I2 in some case. Further, the relationship between the viscosity and melt index was discussed, indicating that I21/I2 as well as MWD is characteristic of all types of PE. Consequently, I21/I2 can be used as a convenient and efficient approach to identifying the type of PE.

A study of the mechanical performance of nanocomposites of polyethylene containing exfoliated boron nitride nanoplatelets

AbstractBoron nitride nanoplatelets (BNNPs) are emerging as a potential candidate for developing polymer‐based thermally conducting nanocomposites that have electrically insulating properties. Generally, the mechanical performance of such polymer‐based nanocomposites, for example, toughness, is often found to be inferior, primarily, owing to the poor dispersion of BNNP, resulting from weaker interfacial interactions between BNNPs and polymer matrices. Here, we report on a successful method to fabricate high density polyethylene (HDPE)/BNNP nanocomposites, with superior mechanical properties, through the in situ exfoliation of the nanofiller via a melt‐extrusion technique. The results obtained showed that the toughness of a nanocomposite with 15 wt% BNNP loading is 18.8 × 103 KJ m−3, that is, about 1.5 times enhancement as compared to the control HDPE sample. The enhancement in mechanical properties can be attributed to a greater degree of homogeneous dispersion of the exfoliated BNNPs achieved using the melt‐ extrusion route. The results that were analyzed through scanning electron microscope and Fourier transform infrared measurements showed that an interesting microstructural feature, named “sunflower‐like” core‐shell structure, formed owing to the relatively stronger interactions between BNNPs and polyethylene chains, which in turn facilitated the uniform dispersion of exfoliated BNNPs in HDPE matrix. This work, therefore, opens up a pathway toward an easy and up‐scalable version for fabricating polymer nanocomposites that have superior mechanical performance and with wider applicability.

Structure–property relationship in film and blow molding type high‐density polyethylene polymers from a slurry‐process industrial plant

AbstractIn this study, the microstructural, flow, and mechanical properties of two commercially available high‐density polyethylene (HDPE) samples with different particle sizes were quantified. Specifically, two different blow molding and film grade HDPEs produced by the same catalyst under different conditions were acquired in powder form after dryer section of an industrial plant. They were fractioned according to their particle sizes into six samples: ≤125, 125–200, 200–315, 315–400, 400–500, and ≥ 500 μm. According to sieve analysis, the film grade (D50 = 304 μm) had larger particle sizes related to the counterpart injection sample (D50 = 289 μm). A peak value in density, bulk density, viscosity molecular weight (Mv), melt flow index (MFI), and comonomer content characteristics was found in the particles with the diameter of 125–200 μm in both samples, indicating extremely non‐homogeneity of these HDPE samples. Chemical composition distribution (CCD) of the as received polymers as well as sieved fractions was surveyed via SSA or TREF analyses. The film sample represented lower MFI and density and higher Mv and comonomer content in all fractions, originated from different reactor conditions during the samples synthesis, which translate into improved mechanical properties comparing with the blow molding sample.

Effect of Hybrid Fillers of Bamboo Fiber and Commercial Glass Fiber on High Density Polyethylene Matrix

The focus of this research work is to study the effect of hybrid fillers of bamboo fiber and commercial glass fiber on high density polyethylene (HDPE) matrix without interfacial coupling agent. The hybrid composite was formed through melt blending method using two-roll mixing mill at temperature of 160 oC and was shaped using compression molding machine. The highest value of Tensile Modulus at break and Hardness were obtained at hybrid ratio of 70 % of HDPE/ 15 % bamboo/ 15 % glass particles (H/B15/G15). However, the inclusion of the hybrid fillers did not show any significant difference in Impact strength from the molded blank HDPE samples (H/B0/G0) while the percentage water absorbed by the samples predominantly decreased as the content of the commercial glass filler was increase in the HDPE matrix.

Moisture and oxygen barrier properties of glass, PET and HDPE bottles for pharmaceutical products

The purpose of this study was to evaluate the influence of the material and volume/different finish diameters in the moisture and oxygen barrier properties for bottles for pharmaceutical products. Samples of glass, polyethylene terephthalate (PET) and high-density polyethylene (HDPE) bottles with different volumes (30, 60 and 120 cm3) and finish diameters (18, 24 and 28 mm) were studied. It was previously verified that the integrity of the closure was not dependent on the torque applied to the polypropylene (PP) cap and not influence the barrier properties of the bottles. Provided integrity of the cap for all analyzed samples, water vapor transmission rate (WVTR) of glass increased with increase in finish diameter for the same bottle size, due to a large area exposed for moisture permeation through the PP cap. WVTR of PET and HDPE are dependent by the bottle size and its surface area since moisture permeability occurs preferentially by the bottle. The influence of the material in the moisture barrier properties have been confirmed by the WVTR results obtained for the same bottle volume (30cm3/24 mm) with average values of 0.07, 9.9 and 0.8 mg.day−1.bottle−1 at 40 °C/75%RH for glass, PET and HDPE, respectively. Glass represents the greatest oxygen barrier, followed by PET and HDPE for the same bottle size.

Data-Driven Modelling of Polyethylene Recycling under High-Temperature Extrusion.

Two main problems are studied in this article. The first one is the use of the extrusion process for controlled thermo-mechanical degradation of polyethylene for recycling applications. The second is the data-based modelling of such reactive extrusion processes. Polyethylenes (high density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE)) were extruded in a corotating twin-screw extruder under high temperatures (350 °C < T < 420 °C) for various process conditions (flow rate and screw rotation speed). These process conditions involved a decrease in the molecular weight due to degradation reactions. A numerical method based on the Carreau-Yasuda model was developed to predict the rheological behaviour (variation of the viscosity versus shear rate) from the in-line measurement of the die pressure. The results were successfully compared to the viscosity measured from offline measurement assuming the Cox-Merz law. Weight average molecular weights were estimated from the resulting zero-shear rate viscosity. Furthermore, the linear viscoelastic behaviours (Frequency dependence of the complex shear modulus) were also used to predict the molecular weight distributions of final products by an inverse rheological method. Size exclusion chromatography (SEC) was performed on five samples, and the resulting molecular weight distributions were compared to the values obtained with the two aforementioned techniques. The values of weight average molecular weights were similar for the three techniques. The complete molecular weight distributions obtained by inverse rheology were similar to the SEC ones for extruded HDPE samples, but some inaccuracies were observed for extruded UHMWPE samples. The Ludovic® (SC-Consultants, Saint-Etienne, France) corotating twin-screw extrusion simulation software was used as a classical process simulation. However, as the rheo-kinetic laws of this process were unknown, the software could not predict all the flow characteristics successfully. Finally, machine learning techniques, able to operate in the low-data limit, were tested to build predicting models of the process outputs and material characteristics. Support Vector Machine Regression (SVR) and sparsed Proper Generalized Decomposition (sPGD) techniques were chosen to predict the process outputs successfully. These methods were also applied to material characteristics data, and both were found to be effective in predicting molecular weights. More precisely, the sPGD gave better results than the SVR for the zero-shear viscosity prediction. Stochastic methods were also tested on some of the data and showed promising results.

Comparative analysis of wear behaviour of commercial polymeric pipe materials under different sliding environments

ABSTRACT The friction and wear behaviour of three commonly used commercial polymeric materials, namely, Acrylic, high density polyethylene (HDPE) and unplastisised polyvinyl chloride (uPVC), was studied experimentally under normal ambient conditions. More specifically, the wear rate and coefficient friction of the materials were evaluated against a mild steel counter disc under three different sliding conditions realised by dry, wet (water) and 5% bentonite-clay water environments, which were then analysed as a function of sliding distance as well as the applied load on the sample. Moreover, in order to visualise the results of the present investigation in a comprehensive manner, the associated major physical and mechanical properties of the materials were also investigated. The vertical pin-on-disc method was used to conduct the study. Both the wear and friction characteristics were strongly linked to the structure of the polymers; HDPE samples being fully crystalline show best wear and friction characteristics, whilst the amorphous Acrylic shows the worst. Optical microscopic analysis of the specimens, particles from the worn surfaces (wear debris) and the counter disc also indicated that Acrylic was most affected by wear, whilst HDPE was least affected. SEM and EDX observations showed that uPVC was most affected by oxidation followed by HDPE and Acrylic. The excellent wear and frictional properties of HDPE, especially, in particle-dense fluid transportation, make it ideal for dynamic applications, particularly with mine debris flows and transporting of slurry.