Biodegradability, mechanical properties, melt flow index, and morphology of polypropylene/amylose/amylose-ester blends

2002 ◽  
Vol 85 (7) ◽  
pp. 1434-1442 ◽  
Author(s):  
Diya Basu ◽  
Chandan Datta ◽  
Amarnath Banerjee
2013 ◽  
Vol 701 ◽  
pp. 42-46 ◽  
Author(s):  
Abd Aziz Noor Zuhaira ◽  
Rahmah Mohamed

This research is to identify the difference in melt flow and mechanical properties in hybrid composites between kenaf and rice husk that each of the filler was compounded with composite material of calcium carbonate (CaCO3) and high density polyethylene (HDPE) in different loading amount. Different filler loading up to 30 parts of kenaf fibers and rice husk particulate were mixed with the fixed 30% amount of CaCO3. Compounded hybrid composite were prepared and tested for melt flow index, tensile and impact strength. Addition of both fillers had decreased melt flow index (MFI). MFI of rice husk/CaCO3 was higher than kenaf/CaCO3 in HDPE composites. Tensile strength, elongation at break and impact properties of both hybrid composites had decreased with increasing filler content. Tensile strength of kenaf/CaCO3 was higher than rice husk/CaCO3 due to intrinsic fiber structure of kenaf which has some reinforcing effect compared to rice husk. While, impact strength of rice husk/CaCO3 was improved with addition of filler but drastically decrease as the rice husk content were increased up to 30% due to high silica content in rice husk. The Youngs Modulus was increased with addition of natural fibers in CaCO3/HDPE composite.


2005 ◽  
Vol 21 (3) ◽  
pp. 219-230 ◽  
Author(s):  
Arup Choudhury ◽  
Mandira Mukherjee ◽  
Basudam Adhikari

The present investigation deals with the viability of the use of recycled milk pouch material, which is a 50:50 mixture of LDPE and LLDPE, and the scope for improvement of its properties by combining it with virgin LDPE-LLDPE (50/50). Melt flow index (MFI), rheological properties, thermal and mechanical properties of the pure materials and their formulated blends containing recycled milk pouches were studied. The properties of the recycled materials were not as satisfactory as those of the corresponding virgin materials. But a significant improvement in viscosity, crystallinity, tensile strength and elongation at break of the recycled LDPE-LLDPE material was achieved by blending it with the corresponding virgin LDPE-LLDPE blend.


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 552
Author(s):  
Luboš Běhálek ◽  
Jozef Dobránsky ◽  
Martin Pollák ◽  
Martin Borůvka ◽  
Pavel Brdlík

The paper deals with the possibility of applying physical methods to detect a thermally degraded recycled material in plastic parts made of polypropylene. Standard methods of evaluating the mechanical properties of the material under static tensile and bending stress, as well as under dynamic impact stress using the Charpy method, were used for the experimental measurements. The rheological properties of materials were monitored using a method involving measuring the melt flow index, while their thermal properties and oxidative stability were monitored using differential scanning calorimetry. Based on the methods used, it can be clearly stated that the most suitable technique for detecting thermally degraded recycled material in polypropylene is the method involving establishing the melt flow index. The bending test seems to be the most suitable method for detecting recycled material by measuring the material’s mechanical properties. Similarly to the melt volume flow rate (MVR) method, it was possible to unambiguously detect the presence of even a small amount of recycled material in the whole from measuring the material’s bending properties. It is clear from the results that in the short term, there may be no change in the useful properties of the parts, but in the long term the presence of degraded recycled material will have adverse consequences on their lifespan.


Author(s):  
С. В. Сайтарли ◽  
В. П. Плаван ◽  
Л. С. Дзюбенко ◽  
О. С. Керенівський ◽  
Д. М. Євдокименко

To develop filled polymer compositions based on polypropylene with different contents of calcite concentrate as a filler and the newest polyolefin elastomer as a modifier; to define the influence of the compositions on their rheological and physico-mechanical properties for production injection molded goods. The values of viscosity, melt flow index, tensile strength, elongation, and impact strength and frost resistance of the compositions depending on their composition are determined by standard methods. The influence of calcite concentrate as a filler and polyolefin elastomer as a modifier on the rheological and mechanical properties of compositions has been determined. With an increase in the amount of filler the physical and mechanical properties of the filled compositions are reduce that is offset by introducing the newest polyolefin elastomer as a modifier in amount of 5 wt. %. Addition of 5 wt. % of polyolefin elastomer in the filled composition gives them frost resistance, wherein the impact strength is higher than for compositions without the modifier even after freezing for 30 days at -18°С. It has been determined that adding of the filler does not increase the viscosity of the compositions, which contradicts the traditional behavior of filled systems. The addition of 5 wt. % of polyolefin elastomer to the filled compositions with calcite concentrate up to 20 wt.% does not change the tensile strength of the compositions which is 24 MPa, but increases elongation by 2 times, impact strength by an average of 8,5 % and frost resistance after freezing compositions at -18 °C for 30 days by an average of 12,6 %. The research results of rheological and physic-mechanical properties allow choosing the rational composition to achieve the desired characteristics of the polymer material for production goods by injection molding. Melt flow index of the compositions increases with increasing amount of filler to 50 wt. %. which does not increase the production costs of the injection molding process in comparison with unfilled compositions.


2013 ◽  
Vol 795 ◽  
pp. 286-289 ◽  
Author(s):  
Abd Aziz Noor Zuhaira ◽  
Mohamed Rahmah

In this research, calcium carbonate (CaCO3) was compounded with rice husk/high density polyethylene (HDPE) and kenaf/HDPE composite at different filler loadings to produce hybrid composites. Melt flow index (MFI) and mechanical properties of hybrid composite was investigated. From the test results, the addition of CaCO3 filler had decreased melt flow index (MFI) on both composites. In terms of mechanical properties, tensile strength, elongation at break and impact strength decreased, whereas Youngs Modulus increased with the increase of CaCO3 in both kenaf/HDPE and rice husk/HDPE composites. Impact strength of unfilled rice husk/HDPE composite was lower than unfilled kenaf/HDPE composite, however impact strength of CaCO3/rice husk/HDPE hybrid composite were found to have slightly higher than CaCO3/kenaf/HDPE hybrid composite with addition of 10% and 20% of CaCO3.


2018 ◽  
Vol 56 (2A) ◽  
pp. 56-62
Author(s):  
Nguyen Van Khoi

In this article, we investigated effect of carrier resin ratio and anti-oxidation additives content on properties of anti-oxidant additives Masterbatchs (MBs). The characteristics were measured by: melt flow index (MFI), morphology (SEM), tensile strength and elongation at break. The results indicated that: increasing LLDPE content in carrier resin led to decreasing mechanical properties, MFI weren’t uniform in MBs. With 80/20 of LDPE/LLDPE ratio, the tensile strength and elongation at break values were highest (21.0 MPa, 680.5 %). In addition, when increased anti-oxidant additives content, mechanical properties increased to upper limit value, then decreased. With 25 wt.% of anti-oxidant additives, the tensile strength and elongation at break values were highest (21.0 MPa, 654.7 %), MFI were uniform in MBs (12 g/10 m). SEM images were evidence of greatly distribution in sample containing 25 wt.% additives. Consequently, the 90/10 of LDPE/LLDPE ratio, 25 wt.% anti-oxidant additives were selected to prepare MBs. 


Author(s):  
Luiz Gustavo Barbosa ◽  
Cassiano Rodrigo Dalberto ◽  
Edson Luiz Francesquetti

Polypropylene is one of the most used materials in the world because of its easy processability and good mechanical properties under different applications. As a result, a lot of polypropylene waste is being generated and recycling is important. The problem with recycling polypropylene is the changing in the properties when compared to virgin polypropylene. Processability parameters and mechanical properties of traction and impact can be changed after recycling this material, affecting companies in the polymer transformation sector. Thus, this work aims to obtain an empirical equation for the correction of the melt flow index of virgin and recycled polypropylene mixtures and also conducts a study on the mechanical properties of the mixtures comparing them with those of virgin polypropylene. The empirical equation found shows a linear relationship between the melt flow index of the mixture and the percentage amount of virgin polypropylene. From the mechanical properties, it was observed that the stiffness of the mixtures is similar to that of virgin polypropylene, however the energy absorbed under impact is considerably lower, compromising the use of recycled polypropylene for such application.


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