Oxidative Degradation of Polyethylene Filled with Nanosized Crushed Shells of Sea Oysters

2021 ◽  
Vol 887 ◽  
pp. 123-128
Author(s):  
Z. Akhmetshina ◽  
E. Mastalygina ◽  
P. Pantyukhov

The work is devoted to the study of the effect of marine calcium carbonate on the polymer matrix. The composite flat strips based on low-density polyethylene filled by crushed shells of sea oysters, which are the main source of sea calcium, were investigated. Marine calcium carbonate masterbatch was used to reduce the cost and stiffen the resulting composite materials. The effect of the masterbatch concentration on mechanical properties and oxidative degradation were studied. The materials were exposed to three climatic factors (temperature, UV-radiation and moisture). The addition of crushed shells led to embrittlement of the test materials. According to FTIR analysis, the absorption band at 1432 cm-1 attributed to carbonate minerals decreased or completely disappeared after weathering test due to washing out of CaCO3 from the composite.

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 179
Author(s):  
N. S. Yousef

Polypropylene (PP) is a semi-crystalline polymer that is brittle under severe conditions. To meet industry needs, and to increase the applications of polypropylene, its mechanical properties should be improved. In this research, the mechanical properties of polypropylene, such as tensile strength at break, tensile strength at yield, % elongation, and Young’s modulus, were improved using two types of additives. Additives used were calcium carbonate master batch filler composed of 80% calcium carbonate and 20% polyethylene, and a mixture of linear low-density polyethylene (LLDPE)/low density polyethylene (LDPE). Results showed that both tensile strength at break, and tensile strength at yield, decrease with increasing the amount of both additives. Percentage elongation of PP increased using both additives. The modulus of elasticity of PP increases by increasing the amount of both additives, until a value of 20 wt%. Analysis of variance (ANOVA test) or (F-test) shows significant differences between the effect of different weights of LLDPE/LDPE mixture and calcium carbonate filler on the four mechanical properties of polypropylene studied at a level of 0.05. T-tests are applied to compare between the effect of both calcium carbonate master batch filler and the mixture LLDPE/LDPE on the four mechanical properties of polypropylene studied. T-tests show no significant differences between the effect of both calcium carbonate master batch filler and the mixture LLDPE/LDPE on all mechanical properties of polypropylene studied at a level of 0.05.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1821
Author(s):  
Ildar I. Salakhov ◽  
Nadim M. Shaidullin ◽  
Anatoly E. Chalykh ◽  
Mikhail A. Matsko ◽  
Alexey V. Shapagin ◽  
...  

Low-temperature properties of high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and their blends were studied. The analyzed low-temperature mechanical properties involve the deformation resistance and impact strength characteristics. HDPE is a bimodal ethylene/1-hexene copolymer; LDPE is a branched ethylene homopolymer containing short-chain branches of different length; LLDPE is a binary ethylene/1-butene copolymer and an ethylene/1-butene/1-hexene terpolymer. The samples of copolymers and their blends were studied by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), 13С NMR spectroscopy, and dynamic mechanical analysis (DMA) using testing machines equipped with a cryochamber. It is proposed that such parameters as “relative elongation at break at −45 °C” and “Izod impact strength at −40 °C” are used instead of the ductile-to-brittle transition temperature to assess frost resistance properties because these parameters are more sensitive to deformation and impact at subzero temperatures for HDPE. LLDPE is shown to exhibit higher relative elongation at break at −45 °C and Izod impact strength at −20 ÷ 60 °C compared to those of LDPE. LLDPE terpolymer added to HDPE (at a content ≥ 25 wt.%) simultaneously increases flow properties and improves tensile properties of the blend at −45 °C. Changes in low-temperature properties as a function of molecular weight, MWD, crystallinity, and branch content were determined for HDPE, LLDPE, and their blends. The DMA data prove the resulting dependences. The reported findings allow one to understand and predict mechanical properties in the HDPE–LLDPE systems at subzero temperatures.


2015 ◽  
Vol 37 (11) ◽  
pp. 3167-3174 ◽  
Author(s):  
S. Sánchez-Valdes ◽  
E. Ramírez-Vargas ◽  
L.F. Ramos de Valle ◽  
J.G. Martinez-Colunga ◽  
J. Romero-Garcia ◽  
...  

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