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\title{Obtaining an Empirical Equation for Correcting the Melt Flow Index of Virgin and Recycled Polypropylene Mixtures and Analysis of Mechanical Properties of the Blends}
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             \author[1]{Luiz Gustavo  Barbosa}

             \author[2]{Cassiano Rodrigo  Dalberto}

             \author[3]{Edson Luiz  Francesquetti}

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\date{\small \em Received: 9 December 2019 Accepted: 31 December 2019 Published: 15 January 2020}

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\begin{abstract}
        


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.

\end{abstract}


\keywords{recycled polypropylene, melt flow index, mechanical properties of polymers.}

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\section[{Introduction}]{Introduction}\par
olymeric materials are an important group of the materials engineering because their easy production and wide range of applications. This group includes materials such as plastics and rubbers ranging from low density liquids to rigid solids \hyperref[b0]{[1]}.\par
The growth in the consumption of plastics in the world is evident. In 1964 around 15 megatons (Mt) were generated, in 2014 this production reached 300 Mt. This production is expected to double again within 20 years, and by the year 2050 it has practically quadruple \hyperref[b1]{[2]}.\par
Is estimated that if plastics were replaced by other packaging materials, there would be an increase of approximately 60\% in the volume of waste produced, 57\% electricity consumption over the entire product life cycle and between 78 Mt to 170 Mt of complementary greenhouse gas emissions \hyperref[b4]{[3]}.\par
Despite the use of plastics in general, more specifically the polymers, to exhibit a decrease in the generation of waste, their discard, as well of other consumable materials, also contributes to the production of urban waste and for the waste in the oceans with the aggravation of not being biodegradable, soon this residue remains for long periods in the nature \hyperref[b5]{[4]}.\par
One way to mitigate such problem is the reuse of polymeric materials, by secondary or mechanical recycling which according to the Union of the Plastic Material Industry of the State of São Paulo (Sindiplast) and the Environmental Company of the State of São Paulo (CETESB), "  {\ref [?]}is the converting of plastic waste into granules that can be reused by the productive sector to make other products [?]" \hyperref[b6]{[5]}.\par
One of the most used plastics in the world is the polypropylene (PP) wich, due to the great increase in its productive capacity caused its cost to decrease, so it may be used in new much applications. PP has characteristics that allow it to be subjected to many processing techniques such as Injection, Extrusion, Thermoforming, Rotational Molding and Blowing \hyperref[b8]{[6]}. The main application of PP is in the food sector, representing 32\% in products such as: packaging, lids, tupperwares, jars, bottles and gallons. In the consumer goods sector PP represents 17\% of the market and is applied in packaging and boxes. In civil construction represents 3\% of the market and, among others, it replaces asbestos in fibre cement tiles and water tanks, and it serves as a partial substitute of concrete in slabs with the use of BubbleDeck \hyperref[b9]{[7]}. Also, it is a raw material for the Pack Less, a plastic pallet. In the automotive sector it represents 9\% of the market, being used in dashboards, door panels, bumpers, grilles, for example. \hyperref[b10]{[8]}. Therefore, all this material when discarded can be recycled and originate new products. In Brazil, about 8.2\% of the post-consumer polypropylene is recycled, which is processed into pellets through mechanical recycling and subsequently produces packaging, Year 2020 Abstract-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. automobile components and other recycled products \hyperref[b11]{[9]}.\par
However, in its use, recycled PP has different properties in relation to virgin. One of these properties is the Melt Flow Index (MFI), defined by many authors as the material's processability index. The value of MFI is important for defining the polypropylene transformation process and also in the processability and quality of the parts produced with this material, being that PP's that have a higher MFI are more suitable for injection processes \hyperref[b12]{[10]}.\par
In practice, when a polypropylene is recycled presents a higher melt flow index than when virgin. The recycling causes changes in chemical structure, in the melt viscosity, crystallization behaviour, and tensile and fracture properties. The main effect of recycling is the lowering of the melt viscosity, which is attributed to molecular weight decrease and consequently increases the melt flow index \hyperref[b13]{[11]}. From experience, it is known that changing the MIF can be responsible for problems during the plastics process transforming such as bubbles, fillers, poor filling of the mold, in injected parts in which this material is used.\par
In this context, and considering the PP's used for making parts in a plastics processing company in the state of Rio Grande do Sul, Brazil, which uses both recycled and virgin PP's, the purpose of this work is to obtain an equation to correct the melt flow index of virgin and recycled polypropylene mixtures in order to keep it within the processability values required by the company and standardize the material used. To verify if the parts injected with the mixture between virgin and recycled PP's attend the technical specifications, the mechanical properties of traction and impact were tested.\par
Its important to note that recycled polypropylene, in addition to having an interesting ecological bias, is also more economically viable. Therefore, virgin and recycled PP mixtures can attend projects requirements and economic and environmental demands. 
\section[{II.}]{II.} 
\section[{Materials and Methods}]{Materials and Methods} 
\section[{a) Materials}]{a) Materials}\par
Neat polypropylene (PPv), commercial grade PP CP442XP, was provided by Braskem S.A. (Brazil) with a melt flow index of 26g/10 min (230ºC / 2.16 kg), with yield stress of 32 Mpa.\par
Polypropylene from secondary recycling (PPr) with a many different melt flow index: 5.91, 5.93, 7.70, 8.23, 8.36 and 12.29 g / 10 min (230ºC / 2.16 kg) was provided by Coplast -LTDA from Manaus city (Amazonas, Brazil). 
\section[{b) Methods}]{b) Methods} 
\section[{i. Mixture preparation}]{i. Mixture preparation}\par
The materials used for the measure of the melt flow index were blended in the proportions shown in Table \hyperref[tab_0]{1}. The specimens for the tensile and impact tests were injected in the proporcional for 30\% of virgin PP and 70\% of recycled PP, following the dimensional requirements of ASTM D638-02a and ASTM D256-02, respectively. Table \hyperref[tab_1]{2} shows the parameters used during their injection. ii. Obtaining an equation to melt flow index of virgin and recycled polypropylene mixture The obtaining of an equation relating the melt flow index with the different proportions of PPv and PPr, was carried out empirically, carrying out tests with the different mixtures. After the rheological tests were performed, MFI x \%PPV graphics were generated, and so the linear equations and the general equation was obtained of the melt flow index as a function to percent of virgin polypropylene in the mixtures. 
\section[{c) Characterization}]{c) Characterization} 
\section[{i. Melt Flow Index -MFI}]{i. Melt Flow Index -MFI}\par
The experiment was accomplished in IFRS -Campus Farroupilha, in Farroupilha city (Rio Grande do Sul, Brazil), using an INSTRON CEAST equipment, type 7023, at a temperature of 230°C , 2.16 kg and 420 seconds to stabilization in according to ASTM D1238. 
\section[{ii. Differential Scanning Calorimetry (DSC)}]{ii. Differential Scanning Calorimetry (DSC)}\par
The crystallization (Tc) melting (Tm) temperatures, and percentual of Polypropylene and polyethylene were measured by differential scanning calorimetry on a DSC 6000 PerkinElmer. Samples of 8 mg were analyzed under nitrogen atmosphere under a flow rate of 20 mL/min. In order to erase their thermal history, samples were initially heated at 30°C to 200°C with rates of 50°C/min and kept at 200ºC for 2 min. Then, they were cooled down to 30°C with rates of 20°C/min to determine the crystallization temperature. A second heating to 200ºC with rates of 20°C/min was conducted to evaluate the melting temperature of the composite.\par
The percentage of polyethylene (PE) and polypropylene (PP) in the composite was calculated using the melt enthalpy reference value obtained from the curves of the samples analyzed. To obtain the results, the method developed by Zamin \hyperref[b14]{[12]} was used, in which, by the ratio Y = (Î?"HPE / Î?"HPP), is possible to determine PE percentage in the material, by the equation 1:Y = 0.001X² -0.0029X + 0.0804\textbf{(1)}\par
Where:Y = (Î?"HPE / Î?"HPP) ratio X1 (+) = Percertage of PE in te material X2 (-) = Disregard\par
iii. Fourier Transform Infrared Spectroscopy -FTIR Fourier transform infrared (FTIR) spectroscopy analysis was performed using a PerkinElmer Frontier spectrophotometer with an attenuated total reflectance (ATR) accessory. Each spectrum was obtained using five scans ranging from 4000 to 600 cm -1 at a resolution of 4 cm -1 . 
\section[{iv. Mechanical properties}]{iv. Mechanical properties}\par
The tensile test were performed according to ASTM D638-02a, operating at a speed of 5 mm/min and at room temperature. Five specimens of each mixture were tested and then the mean values of elastic modulus, yield strength and yield strain were obtained. To perform the tensile tests a universal testing machine model WDWV100E, made by Time Group was used, located in the test laboratory of the IFRS -Campus Erechim, controlled by WinWDW software, and has a 100kN load cell and a strain gauge.\par
Impact tests were performed according to ASTM D256-02 in a controlled environment, with a room temperature of 23 ± 2°C and a relative humidity of 50 ± 10\%. The impact strength value was obtained by the ratio of the average energy absorbed by 8 specimens tested according to the dimensions specified in the standard. The tests were performed with a Zwick Izod impact testing machine, located at the IFRS -Farroupilha Campus. The hammer used for the test provides 4.0 J of energy and was released from a height of 610 mm in relation to base. 
\section[{III.}]{III.} 
\section[{Results and Discussion}]{Results and Discussion} 
\section[{a) Differential Scanning Calorimetry}]{a) Differential Scanning Calorimetry}\par
The Table \hyperref[tab_2]{3} show the results of melting enthalpy (Î?"H), melting temperature (Tm), crystallization temperature and percentage of polyethylene in the material. The table shows that the melting temperatures of the materials have not changed since it is a blend, both were close to those found in the literature, HDPE 125 °C to 135 °C and PP 160 °C to 170 °C \hyperref[b14]{[12,}\hyperref[b16]{13]}. The values shown in Table \hyperref[tab_2]{3}, indicate that the material supplied by the Coplast company is not only composed of polypropylene, but has of 20\% polyethylene. Therefore, the MFI variation does not depend on the percentage of polyethylene present in the composition of the material. 
\section[{b) Fourier Transform Infrared Spectroscopy -FTIR}]{b) Fourier Transform Infrared Spectroscopy -FTIR}\par
The FTIR-ATR spectra of the recycled polypropylenes (PPr) are presented in Figure \hyperref[fig_0]{1}. The FTIR spectra PPr matrices show characteristic bands of PP \hyperref[b17]{[14]}, with stretching of CH and CH 2 bonds between 2965 and 2820 cm -1 , and asymmetric and symmetrical deformations of CH and CH 3 at 1447 and 1378 cm -1 , respectively. Still in Figure \hyperref[fig_0]{1}, is possible to observe that in PPr4 there are changes in the range from 3600 to 3000 cm-1, related to the O-H groups, showing a peak that may be an indication of a lot of humidity in this sample. Its difficult to distinguish between PP and PE just by the FTIR test, as both have similar bands; which proves the presence of both materials is the DSC test.\par
In the graph of Figure \hyperref[fig_0]{1} it is also possible to observe the presence of calcium carbonate in the material, through the absorption bands at 873 and 719 cm -1 , which are characteristic of CaCo 3 \hyperref[b19]{[16]}. The PP's bands are in accordance with the ones found in the literature and can be seen in Table \hyperref[tab_3]{4}.  As the MFI considered ideal is between 9 and 13 (g/10 min) for injection processes in the company requesting the research, to obtain the equation and analyze the mechanical properties, recycled polymers with MFI above 9 (g/10 min) were not used in mixtures with PPv100. The Table \hyperref[tab_4]{5} shows the measured values of melt flow index and the nomenclature used for each raw material studied. Year 2020 
\section[{c) Melt Flow Index}]{c) Melt Flow Index}\par
To evaluate the melt flow index of the raw material with which the company works, rheology tests were carried out on them, the first tests being carried out using 100\% of the recycled material (PPr100) and 100\% of the virgin material (PPv100). The PPv100 presented a MFI of 26 (g/10 min) according to the value provided by Braskem. The Table \hyperref[tab_5]{6} shows the results of melt flow index of the recycled polymer samples with different percentages of virgin.   Where:\par
MFIe: Melt Flow Index of the mixture (g/10min)\par
x: Percentage of PPv in the mixture (\%) R: Correlation coefficient of the line (1)\par
Through the results, the general equation obtained to increase the Melt Flow Index between PPv and PPr mixtures, which is show below:MFIm = MFIr + 0.120712x R=0.988468 (1.6)\par
Where:\par
MFIm: Melt Flow Index of the mixture (g/10min) MFIr: Melt Flow Index of the recycled polypropylene (g/10min)\par
x: Percentage of PPv in the mixture (\%) R: Correlation coefficient of the line (1)\par
Where the MFIr is the linear coefficient of the equation, the value of 0.120712 which is multiplied by the percentage of PPv, it is an average of the slope coefficients of the lines found, and the R (correlation coefficient of the line) is an average of the R's of the all lines, which shows how close to an ideal equation it is. This general equation can be used for any MFIr value as long as mixture with PPv CP202XP. 
\section[{e) Mechanical Properties}]{e) Mechanical Properties}\par
After the study of the mixture of virgin and recycled material to correct the MFI value of some recycled PP and obtained the general equation which will solve the company's problem, tensile and impact tests were carried out with the aim of analyzing the mechanical properties of the different mixtures and comparing them with properties of virgin raw material used.\par
The data obtained by the tensile test are shown in Table \hyperref[tab_6]{7}, where PP M1 has an MFI of 9.50 g/10 min, and PP M2 has an MFI of 10.68 g/10 min. Table \hyperref[tab_6]{7} shows that with the increase in the melt flow index of polypropylene, the yield strenght of the polypropylene also rises. In a comparison between the two mixtures made PP M1 and PP M2 it is possible to visualize an increase of 4.35\% in the yield strength.The virgin material has a value of about 50\% above that presented by the mixture between PP V and PP R of IF = 10.691 (g /10 min).For the chosen mixtures the values of IV. 
\section[{Conclusions}]{Conclusions}\par
In the present work, the mixtures of virgin and recycled polypropylene were analyzed in order to obtain an equation to basically correct the melt flow index required by the company to correct the injection process. The results showed that there is a proportional relationship between the melt flow index and the amount of virgin polymer in the mixture. Therefore, for correction and elevation of the melt flow index of recycled polymer, a certain amount of virgin polymer must be insert to reach the desired index for processing. The evaluation of the mechanical properties showed that the mixtures of virgin and recycled polypropylene maintains rigidity similar that samples with 100\% virgin polypropylene, but under impact the mixtures presents a drastic drop in the absorbed energy. Therefore, for applications that require impact, recycled polymers would have their use compromised. Year 2020 elastic modulus (E) are very close, so both samples have the same stiffness. It is also observed that both mixtures have lower E values than virgin material and therefore are less rigid.\par
As for the yield strain, was observed in table 7 that the values found for both PP M1 and PP M2 are equal. As with the elastic modulus, the highest deformation value is in the virgin material, about 23.5\% in relation to PP M2 .\par
When observed the results of the energy absorbed in the impact, also in the Table \hyperref[tab_6]{7}, is possible to verify that both mixtures of virgin and recycled polymer absorb little energy under impact when compared to 100\% virgin material.\begin{figure}[htbp]
\noindent\textbf{1}\includegraphics[]{image-2.png}
\caption{\label{fig_0}Figure 1 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{}\includegraphics[]{image-3.png}
\caption{\label{fig_1}}\end{figure}
  \begin{figure}[htbp]
\noindent\textbf{1} \par 
\begin{longtable}{P{0.33298969072164947\textwidth}P{0.2015463917525773\textwidth}P{0.09639175257731958\textwidth}P{0.21907216494845358\textwidth}}
Sample\tabcellsep Virgin (\%)\tabcellsep Composition\tabcellsep Recycled (\%)\\
PPv100\tabcellsep 100\tabcellsep \tabcellsep -\\
PPr10\tabcellsep 90\tabcellsep \tabcellsep 10\\
PPr20\tabcellsep 80\tabcellsep \tabcellsep 20\\
PPr30\tabcellsep 70\tabcellsep \tabcellsep 30\\
PPr40\tabcellsep 60\tabcellsep \tabcellsep 40\\
PPr100\tabcellsep -\tabcellsep \tabcellsep 100\end{longtable} \par
 
\caption{\label{tab_0}Table 1 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{2} \par 
\begin{longtable}{P{0.7835390946502058\textwidth}P{0.06646090534979424\textwidth}}
Injection Parameter\tabcellsep Value\\
Maximum holding pressure (MPa)\tabcellsep 35\\
Maximum injection pressure (MPa)\tabcellsep 50\\
Maximum back pressure (MPa)\tabcellsep 8\\
Decompression pressure (MPa)\tabcellsep 55\\
Injection time (s)\tabcellsep 5\\
Temperature of zones 1 to 4 (°C)\tabcellsep 200\\
Temperature of zone 5 (injection) (°C)\tabcellsep 195\end{longtable} \par
 
\caption{\label{tab_1}Table 2 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{3} \par 
\begin{longtable}{P{0.06538461538461539\textwidth}P{0.09444444444444444\textwidth}P{0.10170940170940171\textwidth}P{0.10170940170940171\textwidth}P{0.10170940170940171\textwidth}P{0.10170940170940171\textwidth}P{0.09081196581196581\textwidth}P{0.11987179487179486\textwidth}P{0.07264957264957266\textwidth}}
Sample\tabcellsep MFI (g/10min)\tabcellsep Tm PP (ºC)\tabcellsep Tm PE (ºC)\tabcellsep Î?"H PP (J/G)\tabcellsep Î?"H PE (J/G)\tabcellsep Tc (ºC)\tabcellsep Y = Î?"HPP Î?"HPE/\tabcellsep \% PE\\
PPr2\tabcellsep 5.912\tabcellsep 162.83\tabcellsep 128.88\tabcellsep 42.08\tabcellsep 22.09\tabcellsep 118.09\tabcellsep 0.525\tabcellsep 22.19\\
PPr4\tabcellsep 8.36\tabcellsep 162.34\tabcellsep 128.03\tabcellsep 46.72\tabcellsep 20.35\tabcellsep 118.16\tabcellsep 0.436\tabcellsep 19.51\\
PPr5\tabcellsep 7.70\tabcellsep 163.12\tabcellsep 128.86\tabcellsep 43.38\tabcellsep 19.48\tabcellsep 118.14\tabcellsep 0.449\tabcellsep 20.19\end{longtable} \par
 
\caption{\label{tab_2}Table 3 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{4} \par 
\begin{longtable}{P{0.20863636363636362\textwidth}P{0.5357575757575757\textwidth}P{0.1056060606060606\textwidth}}
Wavenumber (cm -1 )\tabcellsep Peak Assignment\tabcellsep Reference\\
PP Pe\tabcellsep \tabcellsep \\
2952, 2918 and 2838\tabcellsep C-H stretching\tabcellsep {}[14]\\
2720\tabcellsep CH bending and CH3 stretching\tabcellsep {}[15]\\
1456\tabcellsep CH3 asymmetric deformation\tabcellsep {}[15]\\
1376\tabcellsep CH3 symmetric deformation\tabcellsep {}[15]\\
1165\tabcellsep Bending vibration of tertiary carbon\tabcellsep {}[15]\\
974, 841 and 808\tabcellsep C-H deformation out-of-plane\tabcellsep {}[15]\\
873\tabcellsep C-O, calcite, CaCO3\tabcellsep {}[17]\\
719\tabcellsep CO3 , stretching\tabcellsep {}[18]\end{longtable} \par
 
\caption{\label{tab_3}Table 4 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{5} \par 
\begin{longtable}{P{0.39285714285714285\textwidth}P{0.45714285714285713\textwidth}}
MFI measured (g/10 min)\tabcellsep MFI PP\\
26.00\tabcellsep MFI PPv100\\
12.286\tabcellsep MFI PPr1\\
5.912\tabcellsep MFI PPr2\\
5.93\tabcellsep MFI PPr3\\
8.36\tabcellsep MFI PPr4\\
7.70\tabcellsep MFI PPr5\\
8.23\tabcellsep MFI PPr6\end{longtable} \par
 
\caption{\label{tab_4}Table 5 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{6} \par 
\begin{longtable}{P{0.13357142857142856\textwidth}P{0.13964285714285715\textwidth}P{0.13964285714285715\textwidth}P{0.15178571428571427\textwidth}P{0.1426785714285714\textwidth}P{0.1426785714285714\textwidth}}
Percentage of\tabcellsep MFI PPr2\tabcellsep MFI PPr3\tabcellsep MFI PPr4\tabcellsep MFI PPr5\tabcellsep MFI PPr6\\
virgin PP (\% PPv)\tabcellsep (g/10 min)\tabcellsep (g/10 min)\tabcellsep (g/10 min)\tabcellsep (g/10 min)\tabcellsep (g/10 min)\\
0\tabcellsep 5.912\tabcellsep 5.93\tabcellsep 8.36\tabcellsep 7.70\tabcellsep 8.23\\
10\tabcellsep 7.45\tabcellsep 7.2\tabcellsep 9.33\tabcellsep 8.64\tabcellsep 9\\
20\tabcellsep 8.83\tabcellsep 8.15\tabcellsep 9.47\tabcellsep 10.06\tabcellsep 9.28\\
30\tabcellsep 9.5\tabcellsep 9.64\tabcellsep 10.4\tabcellsep 11\tabcellsep 10.68\\
40\tabcellsep 10.4\tabcellsep 11.13\tabcellsep 12.81\tabcellsep 12.45\tabcellsep 12.71\\
50\tabcellsep 12.1\tabcellsep 13.3\tabcellsep 14.446\tabcellsep 13.9\tabcellsep 13.67\\
60\tabcellsep 14.1\tabcellsep 13.3\tabcellsep 14.88\tabcellsep 14.92\tabcellsep 14.91\end{longtable} \par
 
\caption{\label{tab_5}Table 6 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{7} \par 
\begin{longtable}{P{0.20195822454308093\textwidth}P{0.21971279373368147\textwidth}P{0.059921671018276765\textwidth}P{0.0821148825065274\textwidth}P{0.059921671018276765\textwidth}P{0.09986945169712794\textwidth}P{0.1265013054830287\textwidth}}
Year 2020\tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \\
32\tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \\
( ) Volume Xx X Issue V Version I J\tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \\
lobal Journal of Researches in Engineering Gl\tabcellsep Composition PPM1 30\% PPv 70\% PPr2 PPM2 30\% PPv 70\% PPr5\tabcellsep MFI (g/10min) 9.50 10.691\tabcellsep ? e (Mpa) 20.23 ± 0.49 21.11 ± 0.13\tabcellsep ? l 5.67 ± 0.18 5.67 ±0.18\tabcellsep E (Mpa) 1726.40 ± 355.65 1684 ± 176.38\tabcellsep Impact Resistance (J) 0.1225 ±0.0361 0.135 ± 0.0358\\
\tabcellsep 100\% PPv Cp 202Xp\tabcellsep 26\tabcellsep 32\tabcellsep 7\tabcellsep 2023.42\tabcellsep 3.6195\\
\tabcellsep © 2020 Global Journals\tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \end{longtable} \par
 
\caption{\label{tab_6}Table 7 :}\end{figure}
 		 		\backmatter   			 
\subsection[{Acknowledgements}]{Acknowledgements}\par
We would like to thanks the company Cavaletti S.A., for supplying the samples for the experimental tests and by the opportunity to realize of this work. 			  			  				\begin{bibitemlist}{1}
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