Waste EPDM Research Articles

A Study on Aging Characteristics of Asphalt Binders Modified with Waste EPDM Rubber and Tire Pyrolysis Oil

A Study on Aging Characteristics of Asphalt Binders Modified with Waste EPDM Rubber and Tire Pyrolysis Oil

Manufacturing Polypropylene (PP)/Waste EPDM Thermoplastic Elastomers Using Ultrasonically Aided Twin-Screw Extrusion.

The compounding of waste EPDM from postindustrial scrap with polypropylene (PP) is a possible way to manufacture thermoplastic elastomers to solve a significant environmental problem. Accordingly, the present study considers the one-step (OS), two-step (TS), and dynamic revulcanization (DR) compounding methods for the manufacturing of PP/EPDM blends at different ratios of components with the aid of an ultrasonic twin-screw extruder (TSE) at various ultrasonic amplitudes. In the OS method, PP and waste EPDM particles were directly compounded using TSE with and without ultrasonic treatment. In the TS and DR methods, the waste EPDM particles were fed into the TSE and devulcanized without and with ultrasonic treatment. Then, in the TS method the devulcanized EPDM was compounded with PP using TSE without the imposition of ultrasound. In the DR method, the devulcanized EPDM after compounding with curatives was mixed with PP and dynamically revulcanized without the imposition of ultrasound in TSE. The die pressure during compounding was recorded and correlated with the rheological properties of compounds. The mechanical properties of the PP/EPDM blends obtained in the OS and TS methods did not show any improvement with ultrasonic treatment. In the DR method, all the PP/EPDM blends showed a significant increase in the tensile strength and elongation with ultrasonic amplitude and a slight decrease in the Young’s modulus. In particular, a tensile strength of 30 MPa and an elongation at break of 400% were achieved at an ultrasonic amplitude of 13 μm for the PP/EPDM blend at a ratio of 75/25. The complex viscosity, storage, and loss moduli of dynamically revulcanized PP/EPDM blends increased with the ultrasonic amplitude while the loss tangent decreased. At the same time, the results for the blends obtained by the OS and TS methods showed an opposite trend in the dynamic property behavior with the ultrasonic amplitude. Optical micrographs indicated that the blends obtained by the DR method at an ultrasonic treatment at 13 μm showed the lowest sizes of dispersed revulcanized EPDM particles in the PP matrix, leading to the excellent performance of these thermoplastic elastomers.

Investigation of Mechanical and Thermal Properties of Waste EPDM and Polypropylene Mixtures

Investigation of Mechanical and Thermal Properties of Waste EPDM and Polypropylene Mixtures

INVESTIGATION OF MECHANICAL, THERMAL, AND MORPHOLOGICAL PROPERTIES OF EPDM COMPOUNDS CONTAINING RECLAIMED RUBBER

ABSTRACT The disposal of polymeric and hazardous materials is an important global issue. Thus, the mechanochemical reclaiming of waste EPDM rubber was carried out using disulfide oil (DSO), oily waste produced in gas refineries, as a reclaiming agent at a specific operation condition. Reclaimed rubber was characterized by crosslink density, sol-gel, and Mooney viscosity measurements. Following the study, blending of different portions of reclaimed rubber (20, 40, 60, and 80 wt%) with virgin EPDM rubber was carried out. Results showed that the addition of 60 wt% of reclaimed rubber to the virgin EPDM rubber had no adverse effect on the scorch and optimum curing time. Also, mechanical properties of revulcanized rubber improved when 40 wt% of virgin EPDM rubber was replaced with the reclaimed rubber. Scanning electron microscope and thermal gravimetric analyses of the samples revealed the effect of addition of reclaimed rubber on the rubber matrix and thermal stability of revulcanized samples, respectively. This study proposes a new route for solving the problem of disposal of the waste materials.

A new approach for reclaiming of waste automotive EPDM rubber using waste oil

The disposal of polymeric and especially rubber materials is an important global issue. In this work we have used disulfide oil (DSO), the oily waste produced in gas refineries, as a chemical agent for mechanochemical reclaiming of waste EPDM rubber at a specific operation condition. The devulcanization reaction was performed using different concentrations of DSO (5 and 7 phr) and different temperatures (220, 250 and 290 °C). The results confirmed the effectiveness of DSO in decreasing the crosslink density up to 73% at specific reaction conditions. Subsequently, two different portions of the devulcanized rubber (RR) (20 and 40 wt %) were blended with the virgin EPDM rubber to assess the reusability of the recycled product. Accordingly, replacing 40 wt% of RR had no effect on the scorch and the optimum curing time and similar curing rates were obtained. Moreover, the mechanical properties of the revulcanized blends were not worsened and surprisingly were improved in some cases including tensile strength and elongation at break up to 14% and 26% respectively. These results can be used to propose a new method for solving both rubber and disulfide oil disposal issues.

Study on the Functionalization of Waste EPDM and PP Blend

Study on the Functionalization of Waste EPDM and PP Blend

A novel industrial technique for recycling ethylene-propylene-diene waste rubber

Recycling waste rubber has gained importance in recent years. Ethylene-propylene-diene rubber (EPDM) is used to manufacture various automotive parts. Reclaiming EPDM rubber waste is a major problem. Waste powder from discarded EPDM automotive parts was devulcanized using an industrial autoclave which provided both heating and high pressure steam. To aid the devulcanization process, 2-mercaptobenzothiazoledisulfide (MBTS) and tetramethylthiuram disulfide (TMTD) devulcanizing agents, and aromatic and aliphatic oils were also used. A portion of the virgin EPDM rubber in a common formulation for the automotive rubber strips was replaced with the devulcanized product to produce blends, which were revulcanized using a semi-efficient (SEV) vulcanization system. The viscosity, cure and mechanical properties of the blends were subsequently determined. This study showed that the oils had different effects on the devulcanization of the waste powder and MBTS was more efficient than TMTD. Replacing 60 wt% of the virgin rubber in the automotive rubber strips with the devulcanized powder had no adverse effect on the scorch and optimum cure times, crosslink density, rate of cure, and viscosity. Also, when 20 wt% of the virgin rubber was replaced, the hardness, compression set, and modulus at 20% elongation were unaffected. It was concluded that the reclaimed rubber could be used in low percentage in order not to extremely deteriorate the mechanical properties of the virgin rubber. This provided a new effective recycling route for the waste EPDM powder in the automotive rubber strips.

폐 EPDM을 이용한 고무 복합 소재 개발

제대로 재활용되지 못하고 있는 폐 EPDM 즉, 자동차 Weather strip이나 세탁기 가스켓 등에서 재생한 폐EPDM 분말을 적합하고 경제성있는 Polyolefin계 Elastomer와 수지(Binder), 그리고 Filler 및 기타 첨가제를 선정하여, 다양한 배합조건으로 고무 복합소재를 압출 제조하였다. 본 실험에 유익한 기초 실험으로서, 폐 EPDM의 초음파처리 효과, 폐 EPDM복합소재의 폐타이어 복합소재와의 물성 비교, Virgin EPDM과 Devulcanized EPDM과의 비교, 그리고 12 축압출기로 압출한 재료의 물성에의 영향을 고찰하였다. 폐 EPDM을 이용하여 인조잔디 충전재와 카매트용 복합소재를 2 축압출기를 사용하여 압출한 후, 인장시편을 사출하여 인장강도, 신율, 경도의 세가지 물성을 주요 평가지표로 삼고 경제적인 배합처방을 개발하였다. Waste EPDM(W-EPDM) collected from the automotive weather strip and the gasket of a laundry machine has not been effectively recycled. Using this W-EPDM powder and other ingredients, i.e., binder(polyolefin resin, polyolefin elastomer, etc.), filler and additives, various economic rubber composites were made by extrusion. In advance of main experiments, the effects of ultrasonic treatment of W-EPDM on the property of rubber composites, comparison in the property of the composites of W-EPDM with those of virgin and devulcanized EPDM, and waste tire rubber were investigated. Also, the properties of the rubber composites extruded with a 12-screw extruder were compared with those extruded with twin-screw extruder. Various W-EPDM composites for synthetic turf filler and car mat were extruded and injection molded, and 3 main properties of tensile strength, elongation and hardness were investigated to develop economical and proper recipes of the rubber composites.

Research of Low-Temperature Regeneration of Waste EPDM

In this paper, the research of regeneration of waste EPDM has been done on the basis of a lot of reading of literature and collecting of information. It has neither the pollution of gas emission during the recycling of rubber in dynamic desulfurization tank under high temperature and pressure, nor the high energy consuming during the recycling of rubber using regenerant under normal temperature and pressure. Eventually, the regeneration of waste EPDM under low-temperature became a reality.

Thermoplastic Elastomers Based on Waste Rubber and Plastics

Abstract This paper reviews the utilization of waste rubber and waste plastics for the preparation of thermoplastic elastomers (TPEs). TPEs based on ground rubber tire (GRT), waste EPDM rubber, waste nitrile rubber, recycled rubber, latex waste, and waste plastics are described with respect to composition and physical properties. It is found that part of the rubber phase or plastics phase or both in the rubber-plastics blend can be replaced with corresponding waste polymer for the preparation of thermoplastic elastomers. In many cases, the materials prepared from waste polymers show properties comparable to those prepared from fresh polymers. However, in some cases, the materials prepared from waste rubber or waste plastics cannot be classified as TPEs, as the blend compositions show very low elongation at break. Modification of the waste polymer or the use of compatibilizers result in stronger composites.

Utilization of Powdered EPDM Scrap in EPDM Compound

Abstract Processability, curing characteristics and vulcanizate properties of EPDM compounds containing ground waste EPDM (W-EPDM) have been studied. Ground waste was prepared from factory scraps, using a mechanical grinder with silicon carbide abrasive wheel rotating at 2950 rpm. The particle size shows a range between 2 and 50 μm, with an average size of 10 μm. Particle surface seems to be rough and convoluted and mild oxidation during the abrasion enhances the aggregation of particles. Mooney scorch time and the maximum rheometric torque of the EPDM compound decrease gradually with increasing W-EPDM content. Migration of curatives between the virgin rubber and waste rubber phases is believed to be the reason for the variation in the curing behavior. The processability of the EPDM compound shows improvement on addition of W-EPDM (that is, both die swell and extrudate distortion are less). The vulcanizate properties of the W-EPDM-filled EPDM compounds reveal the reinforcing nature of the ultrafine W-EPDM particles. Comparison of W-EPDM with an inert filler like precipitated CaCO3 in an EPDM compound reveals the potential of W-EPDM as a cheap filler in EPDM compounds. It is also found that W-EPDM can be incorporated into the window seal compound formulation and the drop in properties even at 100 phr of W-EPDM is within acceptable limit, thus providing a scope for on-site recycling of EPDM.

Recycling of EPDM waste. I. Effect of ground EPDM vulcanizate on properties of EPDM rubber

Processing, cure characteristics, and mechanical properties of EPDM rubber containing ground EPDM vulcanizate of known composition were studied. Mooney viscosity increases and Mooney scorch time decreases by the addition of the ground vulcanizate. At higher loadings of the ground rubber, the maximum rheometric torque decreases. On addition of ground waste, stress–strain properties and tear resistance increase, whereas heat buildup marginally increases, resilience marginally decreases, low-strain modulus remains constant, and abrasion resistance decreases. The interplay between the filler effect of the ground EPDM and the crosslink density changes of the EPDM matrix is believed to be the reason for the variation in mechanical properties. It is believed that sulfur migration occurs from the raw EPDM matrix (R-EPDM) to the ground waste EPDM (W-EPDM) particle while accelerator migration occurs from W-EPDM to R-EPDM. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3293–3303, 2001

Recycling of EPDM waste. I. Effect of ground EPDM vulcanizate on properties of EPDM rubber

AbstractProcessing, cure characteristics, and mechanical properties of EPDM rubber containing ground EPDM vulcanizate of known composition were studied. Mooney viscosity increases and Mooney scorch time decreases by the addition of the ground vulcanizate. At higher loadings of the ground rubber, the maximum rheometric torque decreases. On addition of ground waste, stress–strain properties and tear resistance increase, whereas heat buildup marginally increases, resilience marginally decreases, low‐strain modulus remains constant, and abrasion resistance decreases. The interplay between the filler effect of the ground EPDM and the crosslink density changes of the EPDM matrix is believed to be the reason for the variation in mechanical properties. It is believed that sulfur migration occurs from the raw EPDM matrix (R‐EPDM) to the ground waste EPDM (W‐EPDM) particle while accelerator migration occurs from W‐EPDM to R‐EPDM. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3293–3303, 2001