Low Density Polyethylene Blends Research Articles

High quality 3D printing of low-density polyethylene blends considering the softening effect of polyolefin elastomer

Polyethylene (PE) is one of the most widely used thermoplastics in the polyolefin family. Despite its numerous applications in the industry, particularly in packaging, 3D printing with PE has been a significant challenge that has received little attention. The main obstacles to successful 3D printing with PE are high shrinkage, weak adhesion to the print bed, and weak interlayers. This paper addresses this problem by introducing Polyolefin Elastomer (POE) as an additive in the 3D printing process. Three different POE-LDPE compounds with varying LDPE weight percentages (90%, 70%, and 50%) were 3D printed and analyzed for their mechanical and microstructural properties. The POE and LDPE were blended using the melt mixing method, and the resulting POE-LDPE granules were directly used as input for the FDM machine. The 3D-printed samples were then subjected to DMTA, tensile, compression tests, and SEM imaging. The DMTA results showed that the glass transition temperature of all three samples fell within the range of 71°C to 78°C. Increasing the POE content and decreasing the LDPE amount from 90% to 50% led to a decrease in the storage modulus. In terms of the tensile test results, it was observed that reducing the LDPE amount and increasing the POE content had a toughening effect on the samples, improving their formability and elongation from 1566% for POE-90wt% LDPE to 2112% and 2829% for POE-70wt% LDPE and POE-50wt% LDPE respectively. However, the tensile strength decreased with an increase in the POE amount. For POE-90wt% LDPE, the tensile strength was 14.06 MPa, and for POE-90wt% LDPE, it was just below 13.96 MPa. The compression test revealed that the addition of POE weakened the yield strength of the samples. SEM images demonstrated that the printability of the 3D-printed POE-LDPE samples decreased as the LDPE amount decreased and the POE amount increased. The images also revealed single-phase and miscible blends. These findings suggest the potential emergence of a new, affordable, biocompatible, and recyclable raw material for 3D printing.

Self-nucleation (SN) and successive self-nucleation and annealing (SSA) as powerful tools to determine the composition of polyolefin post-consumer recycled blends

AbstractFor the incorporation of post-consumer recycled (PCR) resins in mechanical recycling processes, it is crucial to determine their composition accurately. The blends of linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) in PCR film resins pose a challenge due to their varying ratios. This study introduces a quantitative method that employs the successive self-nucleation and annealing (SSA) technique to analyze commercial PCR LLDPE/LDPE blend compositions. Our method is an efficient way to assess these blend compositions, offering an improved analysis compared with traditional methods. We established a series of calibration curves based on the SSA final melting trace to validate our approach. The SSA technique's efficacy was compared with the robust NMR method, showing that SSA can predict LLDPE contents in the blends with comparable accuracy. We demonstrate that the SSA methodology is an accurate and reliable technique for assessing complex waste streams, thereby facilitating the optimization of recycling processes and advancing the goals of sustainable materials management.

Investigating the effect of compatibilizers on environmental stress cracking resistance in polypropylene/low density polyethylene blends

The present study focuses on the effect of octylphenoxy poly(ethyleneoxy)ethanol (IGEPAL CA 630) on the environmental stress cracking resistance (ESCR) of blends of polypropylene (PP) and low-density polyethylene (LDPE) at different weight fractions without and with the addition of two compatibilizers, corresponding to styrene-ethylene-butylene-styrene (SEBS) copolymer and styrene-ethylene-butylene maleate (SEBS-g-MA). Compression molding was used after mixing the melt in a Brabender internal mixer to create the blends. ESCR of the blends was determined by exposing the blends to a solution of IGEPAL CA 630 the presence of stress. Mechanical (tensile) and thermal properties are extracted to evaluate the effect of adding the compatibilizers SEBS and SEBS-g-MA to the blend. In the environmental stress cracking (ESCR) tests, the time to failure increases with increasing PP content, despite PP's greater resistance to ESCR than LDPE. The addition of SEBS-g-MA to the blend significantly improves the flexibility and ESCR performance of PP/LDPE blends with specific weight fractions.

Enhancing the physical properties of recycled low-density polyethylene and virgin low-density polyethylene blend using octanoate starch

Increasing global consumption of low-density polyethylene leads to more polymeric waste and challenges solid waste management. Therefore, the process of recycling or mixing recycled low-density polyethylene (RLDPE) with the same virgin low-density polyethylene (VLDPE) and enhancing the properties of this blend by adding different amounts of bioplastic such as Octanoate starch (OCST) is a good contribution to getting rid of plastic waste and obtaining new materials. This paper mixed the 20, 30 and 50 wt.% from RLDPE with VLDPE to determine the homogeneous blend. Also, 30, 40, and 50 wt. % from OCST were blended with homogeneous as a 20:80 RLDPE: VLDPE to obtain a new hybrid blend containing bioplastic. The scanning electron microscope (SEM) results showed the high surface roughness of the film RLDPE: VLDPE after adding the OCST. The tensile strength, elastic modulus, and hardness of the 20:80 RLDPE: VLDPE blend were 13.0 ± 1.467 MPa, 0.08 ± 0.016 MPa, and 42.3 ± 2.32 Shore A, while the tensile strength, elastic modulus, and hardness of the 12:48:40 RLDPE: VLDPE: OCST were 14.3 ± 1.626 MPa, 0.1 ± 0.032 MPa, and 50.1 ± 2.78 Shore A respectively. On the other hand, the Fourier-Transform Infrared (FTIR) indicated that the strong bands at 1746 cm−1, 2856 cm−1, and 2927 cm−1 indicated stretching deformation of the ester carbonyl group and the methyl and methylene groups of OCST with blend polymers, respectively. The thermal properties as melting point, heat energy consumption, and heat flow difference increased from 122.52 to 123.73°C, −389.41 to −144.43 (mJ), and −77.88 to −28.89 (J/g) when the OCST content increased from 20:80 RLDPE: VLDPE to 12:48:40 RLDPE: VLDPE: OCST. Thermal decomposition led to the formation of functional groups such as hydroxyl and carbonyl on LDPE baskets and an increase in the carbonyl index after adding OCST to the RLDPE: VLDPE blend. The best hybrid blend was 12:48:40 RLDPE: VLDPE: OCST.

Influence of Temperature and Blending Ratio on Product Yield for Co-gasification of Torrefied Palm Kernel Shell and Low-Density Polyethylene

This study investigates the product yields produced from the co-gasification of torrefied palm kernel shell (TPKS) and low-density polyethylene (LDPE). Prior co-gasification, PKS was undergo pre-treatment process at different temperature. The optimum parameter for torrefaction was found at 250 °C for 60 min reaction time with 4.89 wt. % moisture content and 10.48 wt.% fixed carbon. Thus, the result indicated that TPKS a suitable fuel feedstock for futher thermal conversion. Then, TPKS and LDPE were gasified at temperature of 600, 800 and 1000 °C and blending ratio of 10:90, 50:50, 90:10 (TPKS:LDPE) for 60 min reaction time. Based on the findings found that, temperature plays an important role in co-gasification. Higher gasification temperature increases the carbon conversion which improves gasification rate. By varying temperature from 600 to 1000 °C, the gas yield increased whilst tar yield decreased sharply. For the effect of blending ratio, through blending of TPKS and LDPE, the gas and char yield increase, while tar decrease with increase torrefied TPKS ratio. Furthermore, it was observed that the product yields obtained from the co-gasification of TPKS and LDPE at 50:50 blending ratios produce the highest gas yield with low char and tar yield than another blending ratio. Therefore, based on the effect of temperature and blending ratio on product yield shows that the optimum parameter to produce maximum gas yield with minimum tar and char yield are at 50:50 (TPKS:LDPE) blending ratio at 800 °C for 60 minutes reaction time.

Correlation of structure, rheological, thermal, mechanical, and optical properties in Low Density Polyethylene/Linear Low Density Polyethylene blends in the presence of recycled Low Density Polyethylene and Linear Low Density Polyethylene

AbstractPost‐industrial low‐density and linear low‐density polyethylene blown films are mechanically recycled for reutilizing in the production of blown films for packaging applications. This process enables the production of films with lower cost and similar properties while preserving the environment and lowering the amount of waste material disposed of. The mechanical recycling process results in the production of recycled pellets. This process includes chopping, washing, drying, and reprocessing. Mixtures of these recycled materials and their virgin form with various concentrations are shaped into blown films with inherent 70 and 30 wt% loadings for low‐density polyethylene and linear low‐density polyethylene components, respectively. Fourier transform infrared spectroscopy results of the recycled material show no contamination or chemical reaction with other materials. Gel permeation chromatography is carried out on the virgin and recycled low‐density polyethylene and linear low‐density polyethylene, and the results indicate the occurrence of chain session and crosslinking during the recycling process. The decline in the thermal properties of the samples, seen from the differential scanning calorimetry results, indicates the presence of crosslinks. The effect of structural changes caused by the recycling process on the rheological properties is studied. The miscibility of the blend components is evaluated by Cole–Cole plots and then further proved by Han and Van Gurp–Palman curves. Mechanical properties display an upturn following the presence of the crosslinkes. A decline in the optical properties in the films caused by the refraction of light by the crosslink structure in the film bulk and on the surface is evident.Highlights LDPE and LLDPE were recycled according to the circular economy approach Blown films containing virgin and recycled LDPE and LLDPE were produced Chain scission and crosslinking as a result of recycling were studied Rheological, thermal, mechanical, and optical properties were studied

Experimental analysis of blended nanocomposites processed using compression molded microwave process

Microwave irradiation has emerged as a versatile and efficient method for synthesizing polymer nanocomposites, offering advantages such as selectivity, speed, and effectiveness in heating materials. This study explores the blending of low-density polyethylene (LDPE) and polypropylene (PP) with carbon nanotubes (CNTs) using microwave processing. The nanocomposites were characterized for their mechanical properties through tensile and fracture toughness tests. Results indicate that LDPE/CNT blended with PP/CNT pellets exhibited improved Young’s modulus and fracture toughness, while LDPE/CNT blended with PP/CNT powder showed enhanced stiffness and fracture toughness. The critical stress intensity factor ( KIC) increased with higher proportions of PP in both cases, signifying improved crack resistance. XRD and SEM analyses confirmed enhanced crystallinity and proper bonding between polymers and CNTs. Overall, this study demonstrates the potential of microwave processing in producing nanocomposites with enhanced mechanical properties, offering a promising avenue for engineering applications.

Simultaneous Effect of EBR on LLDPE and PDMS Rubber Blends and Its Nanocomposites for Cable Applications.

The impact of electron beam radiation on the blend of linear low-density polyethylene (LLDPE) and polydimethylsiloxane (PDMS) rubber at different doses from 50 to 300 kGy has been investigated. The irradiated sheets were examined for their morphology, gel content, thermal stability, melt behavior, and electrical and dielectric properties. The radiation treatment has reduced both the melting point and crystallinity of base polymers and their blends because of chain scission. As observed, 100 kGy doses of irradiated blend and 3 wt % of loaded nanosilica composite showed comparatively good thermal stability. The phase morphology of the LLDPE: PDMS rubber blend showed a honeycomb-like design before irradiation because of two-stage morphology, which prominently changed into a solitary stage after electron beam irradiation. This is because of intermolecular cross-link arrangement inside the singular parts, just like cross-linking development at the interface. From the AQFESEM study, it is observed that the stacking of nanosilica particles within the blend matrix is greatly reduced after electron beam irradiation. The addition of nanosilica within the blend increased the electrical conductivity and dielectric permittivity. The dielectric breakdown strength has been observed to be the highest for 3 wt % loaded nanocomposite and its irradiated sample. The result indicates that the nanocomposite can be utilized for high-voltage cable applications in indoor and outdoor fields.

Morphologies, structures, and properties on blends of triblock copolymers and linear low-density polyethylene

Abstract Focusing on the study of the phase separation behavior of triblock copolymer and linear low-density polyethylene (LLDPE) systems helps to understand the influence of microstructure on the properties of poly(vinylcyclohexane)-b- poly(ethylene)-b-poly(vinylcyclohexane) (PVCH-PE-PVCH/LLDPE) blends. We prepared a series of blends of LLDPE and PVCH-PE-PVCH and explained their compatibility from the microstructure. The research findings indicate that despite having similar block compositions, PVCH-PE-PVCH with a higher molecular weight exhibits significantly stronger phase separation and crystallization ability compared to PVCH-PE-PVCH with lower molecular weight. In PVCH-PE-PVCH/LLDPE blends, the addition of 10 %, 20 %, and 30 % LLDPE induces earlier crystallization and crystal phase separation of polyethylene (PE) fragments. In addition, compared to the lower molecular weight of PVCH-PE-PVCH, the higher molecular weight of PVCH-PE-PVCH exhibits a higher tendency for independent crystallization and shows significant crystal phase separation during the cooling crystallization process when blended with LLDPE. The PE segments in the lower molecular weight of PVCH-PE-PVCH can more easily enter the nanoscale domain of LLDPE. Impact fracture electron microscopy also reveals better compatibility between the lower molecular weight of PVCH-PE-PVCH and LLDPE compared to the higher molecular weight of PVCH-PE-PVCH. Furthermore, the blends of lower molecular weight of PVCH-PE-PVCH and LLDPE exhibit a greater growth rate in elongation at break.

Theoretical and experimental investigation of the compatibilization agent contribution to the interactions of polymer blend (PP/LDPE): Thermal, morphological, and DFT insights

In this research, we looked at the impact of (styrene-ethylene/butylene-styrene) SEBS 5 % wt and (maleic anhydride grafted SEBS) SEBS-g-MA 5 % wt as compatibilizer agents of polypropylene (PP)/low-density polyethylene (LDPE) blends. Compression molding was used after mixing the melts in a Brabender internal mixer to create the blends. Scanner electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the structural and surface behaviors of the blends and their morphology. FTIR analysis showed a weak and broad absorption peak at 1650 cm−1 for PP, LDPE and their blend, which signals the presence of carbonyl groups, and therefore oxidation of the blend. Upon addition of SEBS (styrene ethylene/butylene styrene) and SEBS-g-MA (SEBS grafted with maleic anhydride), the absorption of the carbonyl group decreases, so the peak at 1650 cm−1 becomes smaller. SEM analysis showed an improvement in the morphology and interfacial adhesion of the mixtures with the use of SEBS and SEBS-g-MA. These results suggest that the use of compatibilizers can lead to improved properties for PP/LDPE blends in various applications. Molecular modeling was also used to infer the effects of the compatibilizing agent on the properties of PP-LDPE blends. According to molecular dynamics simulations, the inclusion of SEBS dramatically increases the binding interaction energies for the 3PP/3PE and 3PP-3PE-1SEBS-g-MA systems, going from 440 kcal/mol to 880 kcal/mol, respectively. Density functional theory calculations further confirm the compatibilization role of SEBS-g-MA on the blend. In particular, Quantum molecular descriptors and the density of states demonstrate SEBS-g-MA's involvement as an intermediate in promoting PP and LDPE compatibility. Overall, our results suggest that SEBS-g-MA is a potential PP-LDPE compatibilizer.

LDPE/PCL nanofibers embedded chlorhexidine diacetate for potential antimicrobial applications

In this study, we described the process of developing antimicrobial nanofibers using a solution-based electrospinning technique. The nanofibers were composed of a 40:60 blend of low-density polyethylene (LDPE) and polycaprolactone (PCL), loaded with chlorhexidine diacetate (CHD).The diameter of the nanofibers was measured for LDPCL (235 nm), but it changed to 148, 194, and 325 nm for LDPCL-CHD 1%, 3%, and 5%, respectively. The hydrophilic properties of the nanofibers were significantly improved by incorporating CHD. Also, the contact angle was reduced from 116 ± 5° to 37 ± 2°. The CHD was released from the nanofibers by an initial immediate release and then by extended-release. The released CHD from the nanofibers was found to effectively reduce the formation of biofilms when exposed to microorganisms such as S. aureus and E. coli compared to the control group (LDPCL). The drug-loaded nanofibers were found to be non-cytotoxic when incubated with L929 fibroblast cells for the duration of 24 and 72 h. The study findings suggest that antimicrobial nanofibers have potential applications in preventing implant-related infections caused by (S. aureus and E. coli).

Polymer Packaging through the Blending of Biowaste Oyster Shell and Low-Density Polyethylene: A Sustainable Approach for Enhanced Food Preservation.

This research delves into the impact of incorporating thermally treated oyster shell powder (TOS), a biowaste filler, into low-density polyethylene (LDPE) to develop a LDPE/TOS blend, aiming at enhancing food packaging materials. The LDPE/TOS blend portrays advantageous characteristics such as augmented mechanical strength, thermostability, crystallinity, water absorption, and improved hydrophobicity with TOS content up to 50%. Microstructure analysis reveals a transition from a sparse to a more interconnected structure, contributing to the amplified tensile strength. The blend demonstrates increased barrier properties against water vapor transmission, which is attributed to elongated diffusion paths induced by the TOS particles. Application of the blend material in vegetable preservation trials manifested a substantial reduction in water loss compared to pure LDPE or no packaging. This biowaste-based blend film extends the shelf-life of chicken significantly when compared to that of pure LDPE. Importantly, the LDPE/TOS blend exhibits excellent antibacterial properties against both Escherichia coli and Staphylococcus aureus.

Thermal, mechanical and rheology of EVA/wax and wax/LLDPE blends as a carrier vehicle for investment casting pattern

ABSTRACT Different ratios of wax/ethylene vinyl acetate (EVA) and wax/linear low-density polyethylene (LLDPE) blends were prepared using one-step extrusion process to investigate their potential as carrier vehicles for pattern material for investment casting. The thermal, mechanical and rheological properties were characterised. Thermal analysis was done by thermogravimetric analysis (TGA) and differential scanning calorimetry. Mechanical properties were characterised by three-point bending and thermomechanical analysis, whereas the rheological properties were characterised by oscillatory rheometry. The TGA analysis showed that the incorporation of EVA or LLDPE into wax matrix improved the thermal stability properties of the blend. This can be attributed to an enhanced phase adhesion. The melting and solidification behaviour of the blends had intermediate temperatures between wax and EVA. The EVA/wax blends displayed evident viscosity shifts as compared to the viscosity of wax. The incorporation of EVA into wax significantly altered its mechanical properties. Fourier transform infrared spectrometry for both wax/EVA and wax/LLDPE showed a predominant presence of CH2 and carbonyl group in the blend, and the mechanical properties of neat wax were improved when EVA and LLDPE were incorporated into wax.

Ageing characteristics of polyethylene-modified asphalt binders blended with different compatibilisers

ABSTRACT In this study, virgin low-density polyethylene (LDPE) and recycled polyethylene (RPE) were blended with an asphalt binder in combination with compatibilizers such as styrene-butadiene-styrene (SBS), Elvaloy, sulfur, and polyphosphoric acid (PPA): LDPE, LDPE + SBS + Sulfur, LDPE + Elvaloy, LDPE + Elvaloy + PPA, LDPE + sulfur, RPE, RPE + sulfur, and RPE + PPA. This study aimed to investigate (1) the distribution of PE in asphalt binder, (2) chemical changes in the binder due to the addition of compatibilizers, and (3) the ageing characteristics and their effects on the rheological and performance properties. Micrographs revealed that the LDPE dispersity improved with the addition of Elvaloy. The PE blends with sulfur met the target performance grade of PG76V-10. The PE blends with sulfur exhibited the highest fatigue life at low strain levels and degraded rapidly with an increase in strain level. The LDPE blends with Elvaloy experienced the least degradation in fatigue life with an increased strain level; this low ageing susceptibility was due to the lowest carbonyl (I c =o) and sulfoxide (I s=o) index values.

A Systematic Investigation on the Influence of Intumescent Flame Retardants on the Properties of Ethylene Vinyl Acetate (EVA)/Liner Low Density Polyethylene (LLDPE) Blends.

Because of their high filler loadings, commercial-grade clean flame-retardant materials have unstable mechanical properties. To address this issue, intumescent polymers can be used to develop clean flame retardants with very low levels of smoke and toxicity generation. An intumescent flame retardant (IFR) system composed of red phosphorus (RP), zinc borate (ZB), and a terpolymer of ethylene, butyl acrylate, and maleic anhydride (EBM) was used to prepare EVA (ethylene-vinyl acetate) and EVA/LLDPE (linear low-density polyethylene) composites; their mechanical and flammability properties were systematically investigated. The limiting oxygen index (LOI) of the EVA/LLDPE (as base material) composite containing RP and ZB mixed with nonhalogenated flame retardant, mainly magnesium hydroxide (MH) and coadditives, including processing aids and thermal stabilizers, was established. RP was found to have little effect on the tensile properties of EVA/LLDPE 118W/120 phr flame-retardant (MH + RP) composites. There was a minute difference in the effective trend of RP between tensile strength and elongation at break. Following the addition of ZB, the elongation at break of the composites gradually decreased with increasing RP content and then leveled off when the RP content was over 10 phr. Mechanical properties (elongation at break and tensile strength) can be best maintained at below 10 phr content of RP. The mechanical properties decreased with lower amounts of EBM content. In addition, flame retardancy increased when the EBM content decreased. The findings further revealed that MH and RP have poor compatibility, yielding poor mechanical properties. The LOI greatly increased with RP content, even though the total content of flame retardants (main + intumescent flame retardant) was the same in all formulations. Only over 5 phr RP content formulations passed V-0 of the UL-94 test. When under 5 phr, the RP content formulations did not pass V-0 of the UL-94 test.

Blending of Low-Density Polyethylene and Poly(Butylene Succinate) (LDPE/PBS) with Polyethylene-Graft-Maleic Anhydride (PE-g-MA) as a Compatibilizer on the Phase Morphology, Mechanical and Thermal Properties.

It is of significant concern that the buildup of non-biodegradable plastic waste in the environment may result in long-term issues with the environment, the economy and waste management. In this study, low-density polyethylene (LDPE) was compounded with different contents of poly(butylene succinate) (PBS) at 10-50 wt.%, to evaluate the potential of replacing commercial plastics with a biodegradable renewable polymer, PBS for packaging applications. The morphological, mechanical and thermal properties of the LDPE/PBS blends were examined in relation to the effect of polyethylene-graft-maleic anhydride (PE-g-MA) as a compatibilizer. LDPE/PBS/PE-g-MA blends were fabricated via the melt blending method using an internal mixer and then were compression molded into test samples. The presence of LDPE, PBS and PE-g-MA individually in the matrix for each blend presented physical interaction between the constituents, as shown by Fourier-transform infrared spectroscopy (FTIR). The morphology of LDPE/PBS/PE-g-MA blends showed improved compatibility and homogeneity between the LDPE matrix and PBS phase. Compatibilized LDPE/PBS blends showed an improvement in the tensile strength, with 5 phr of compatibilizer providing the optimal content. The thermal stability of LDPE/PBS blends decreased with higher PBS content and the thermal stability of compatibilized blends was higher in contrast to the uncompatibilized blends. Therefore, our research demonstrated that the partial substitution of LDPE with a biodegradable PBS and the incorporation of the PE-g-MA compatibilizer could develop an innovative blend with improved structural, mechanical and thermal properties.

Reusing Surlyn® Ionomer Scraps in LDPE Blends: Mechanical and Thermal Properties

This study aimed to evaluate the possibility of reusing industrial scraps of Surlyn® ionomer by obtaining blends with Low-Density Polyethylene (LDPE). Blends of LDPE and Surlyn® scraps were obtained by extrusion with compositions ranging from 25 to 75 wt% of the ionomer. Their melt flow index (MFI), morphology (SEM), mechanical (tensile, flexural, impact tests) and thermal properties (DSC, TGA, HDT tests) were analyzed. The morphology of the blends presented two phases, indicating the immiscibility of phases. Surlyn® incorporation promoted a decrease in the degree of crystallinity of LDPE and a slight increase in the thermal decomposition temperature. In addition, Surlyn® decreased the decomposition rate of LDPE. However, the decrease in the degree of crystallinity did not affect the mechanical properties of the blends. Incorporating ionomer in LDPE promoted an increase in tensile and flexural strength, tensile and flexural modulus and strain at break. Impact strength decreased with increasing ionomer concentration.

Intrinsically Heat Tolerant, UV Resistant EVA/ LDPE thermoplastic elastomeric encapsulant – An alternative for conventional crystalline silicon PV module encapsulant

28% vinyl acetate content Ethylene Vinyl Acetate copolymer (EVA) and Low Density Polyethylene (LDPE) blend is a newly developed thermoplastic elastomeric encapsulating system for silicon Photovoltaic (PV) module. Differential scanning calorimetry (DSC) studies has been revealed the inter-miscibility nature of these two polymers blend in the amorphous zones. Thermogravimetric analysis (TGA) result confirms that the EVA-LDPE blend is more thermal stable than the pristine EVA. Encapsulation provides electrical insulation between the solar cells and the electrical circuit of the PV module. Electrical insulation property in terms of DC surface resistivity (SR) and DC volume resistivity (VR) were studied. Insulation property of EVA-LDPE blends under UV radiation has been explored in this article and the change in insulation property has been correlated with the degradation factors. Accelerated UV ageing was performed as per cycle 2 of ASTM G 154 – 2016 for 1000 hours. The thermal resistance and electrical insulation properties were significantly reduced for pristine EVA after 1000 hours UV ageing while >52% property retention found for EVA-LDPE blend.

Dihydroxy Polyethylene Additives for Compatibilization and Mechanical Recycling of Polyethylene Terephthalate/Polyethylene Mixed Plastic Waste.

Polymer blend compatibilization is an attractive solution for mechanical recycling of mixed plastic waste because it can result in tough blends. In this work, hydroxy-telechelic polyethylene (HOPEOH) reactive additives were used to compatibilize blends of polyethylene terephthalate (PET) and linear low-density polyethylene (LLDPE). HOPEOH additives were synthesized with molar masses of 1-20 kg/mol by ring-opening metathesis polymerization of cyclooctene followed by catalytic hydrogenation. Melt-compounded blends containing 0.5 wt % HOPEOH displayed reduced dispersed phase LLDPE particle sizes with ductilities comparable to virgin PET and almost seven times greater than neat blends, regardless of additive molar mass. In contrast, analogous blends containing monohydroxy PE additives of comparable molar masses did not result in compatibilization even at 2 wt % loading. The results strongly suggest that both hydroxy ends of HOPEOH undergo transesterification reactions during melt mixing with PET to form predominantly PET-PE-PET triblock copolymers at the interface of the dispersed and matrix phases. We hypothesize that the triblock copolymer compatibilizers localized at the interface form trapped entanglements of the PE midblocks with nearby LLDPE homopolymer chains by a hook-and-clasp mechanism. Finally, HOPEOH compounds were able to efficiently compatibilize blends derived solely from postconsumer PET and PE bottles and film, suggesting their industrial applicability.

Rheology modifier additive for enhanced processability of polyethylene forblown‐Filmapplications

AbstractPolyethylene is a versatile polymer suitable for a large variety of flexible and rigid packaging applications. Its mechanical and rheological properties can be tuned across a wide range by controlling its molecular architecture, such as the amount and distribution of olefinic comonomers (short chain branching), long chain branching, and molecular weight distribution. Linear low‐density polyethylene (LLDPE) is known for its high toughness which enables downgauged film structures and low‐density polyethylene (LDPE) is known for its excellent shear thinning and melt strength which enables enhanced processability and high throughput, such as on blown film lines. In order to obtain a balance of toughness and processability on films produced on blown film lines, blends of LLDPE and LDPE are commonly used. In this paper, we describe additive‐based approaches, including a new product, DOWLEX™ (TM = trademark of the Dow Chemical Company (“Dow”) or an affiliated company of Dow) GM AX01, which enhances melt strength and other rheological properties of polyethylene, enabling fabrication of films with lower LDPE content while still maintaining excellent rheological properties and higher toughness versus conventional LLDPE/LDPE blends. The higher toughness enables downgauging without loss of mechanical properties, which in turn reduces consumption of polymer resulting in a more sustainable solution.