апрель 2019

Recycling of constructional plastics with additives of exhausted polyethylene

P. Derkach , Деркач Олексій Дмитрович Деркач О. Д. , Коваленко Вадим Леонидович Коваленко В. Л.
Химия и современные технологии
Abstract / Full Text

Nowadays polymeric and composite materials play a key role in machinery building, demonstrating high level of characteristics of mechanisms and machines. Annual demand on these kind of materials is constantly increasing and their worlds’ output has been equal to the production of cast iron in previous year. Meanwhile used polymeric materials and designed details on their base, that’s been expanded their service life is a dangerous source of anthropogenic pollution. It’s proposed to develop modernization technology for PCM polyethylene wastes, that allows effectively deal with the subject of improving of mechanisms and machines, at the same time encourage utilization of used polymers, reduce environmental pressure in the regions where technology implemented, and bring additional education themes into education process in the colleges and universities.

The main objective of this work – is to estimate an impact on used polyethylene, РЕ-500 and РЕ-1000 models, while approach them as a fillers, on phisicotechnical characteristics of constructional plastics based on polyamides. To achieve this goal it is necessary to solve the following tasks: 1) to estimate characteristics of polymer composite material in case of adding used polyethylene; 2) to recommend spheres of applications and make experimental details.

Methods. Worn-out details and unacceptable elements, wastes from used polyethylene РЕ-500 and РЕ-1000 were comminuting to the size of 3…5 mm and adding them in the volume of 10% of weight to materials UPA-6-30 and Nylon 66. To mix equally in their electro-magnetic field. To control the uniformity of distribution of materials in details with help of micrometric shots on a microscope Neofot-30 (Germany).

Methods of samples studying.

− studying impact resilience of materials set-up with help of copra КМ-0,4 for Charpy impact test in accordance with GOST 4647-80;

− investigation of strength properties conducted on an experimental machine FP-100 (Fig.2), in accordance with GOST 4651-82;

− density of samples was determined by method of hydrostatic weighing in the aquatic environment in accordance with GOST 15139-69;

− Vicat softening temperature was estimated by tool PTB-І-ІІ G.

The study of influence an exhausted polyethylene on change of new materials properties: 1) it was defined changes of impact toughness, strength, temperature resistance; 2) by optical tests was determined evenness of distribution of used polyethylene into the binder structure of findings.

Results. The use of waste polyethylene of РЕ mark decreases physico-mechanical characteristics in received PCMwith the exception of impacting viscosity. It is shown that such an indicator as the stress of the boundary of the volume of compression is high (about 100 MPa), which indicates the possibility of using PCM data, for example, for bearings of parallelogram mechanisms of sowing machines, where the pressure value is within the range of 23 to 30 MPa

 Besides, adding РЕ supposed to reduce details’ water absorption, because of polyethylene is not absorbing moisture.

Received polymeric materials with use of wasted polyethylene of РЕ-500 and РЕ-1000 grades can serve, as construction materials at regimes, which correspond to characteristics of new PCM. Presence of carbon fibers in composites such as UPA-6-30+РЕ-500 (10%) and UPA-6-30+РЕ-1000 (10%) allows applying details, made of these materials without normative greasings.

We take into consideration, that properties of РЕ-500 and РЕ-1000 are close to one another, we added only РЕ-500 to material Nylon 66. In addition, from micro photo (Fig. 1) we can see that evenness of compounding is satisfactory: there is no locules (cluster, concentration) of filling mass, defects and so on.

Figure 1 − Micrometric measurements of samples’ surfaces are shown on shots: a) Nylon 66 and b) Nylon 66+ exhausted polyethylene РЕ-500 (10%).

Thus, we believed that anisotropic of obtained materials were provided and hereafter samples were put to the following test.

It was estimated, that using used polyethylene, as a filler, applied to Nylon 66  in amount of  10 % weight lead to declining of ultimate  tensile strength on compression to 17 % (from 60 MPa to 49,7 MPa).