Poly(Vinyl Alcohol) Fiber Reinforced High Density Poly(Ethylene) Composites: Melting and Crystallization Behavior

2018 ◽  
Vol 773 ◽  
pp. 100-105
Author(s):  
Umi Rofiqah ◽  
Achmad Chafidz ◽  
Lilis Kistriyani ◽  
Mujtahid Kaavessina ◽  
Muhammad Rizal ◽  
...  

In the present study, high density poly(ethylene) (HDPE)/poly(vinyl alcohol) (PVA) fiber composites were prepared via melt blending technique using a co-rotating twin screw extruder (TSE). The effect of four different PVA fiber concentrations (i.e. 0, 5, 10, 20 wt%) on the melt and crystallization behavior of the HDPE/PVA fiber composites were investigated. The surface morphology of the composites was analyzed by a scanning electron microscopy (SEM). Whereas, the melt and crystallization behavior of the composites were analyzed by a differential scanning calorimetry (DSC). The SEM analysis on the cryo-fractured surface of the HDPE/PVA fiber composites exhibited that the PVA fibers were well blended/distributed in the HDPE matrix. Additionally, the DSC test results showed that the addition of PVA fiber in the HDPE matrix did not significantly change the melting peak temperature (Tm) of the composites. Furthermore, a slight decrease of the crystallization peak temperature (Tc) can be observed when the PVA fiber was incorporated in the HDPE matrix, which indicated a weak nucleation ability of the PVA fibers in the HDPE crystallization process. The same trend was also observed for the crystallinity index (Xc). The crystallinity index of the composites decreased with increasing PVA fiber loadings.

2021 ◽  
Vol 315 ◽  
pp. 114-119
Author(s):  
Achmad Chafidz M.S. ◽  
Dewi Selvia Fardhyanti ◽  
Megawati ◽  
Prima Astuti Handayani ◽  
Muhammad Rizal

This paper focuses on the preparation of High Density Polyethylene/Poly (Vinyl Alcohol) Fiber composites which was fabricated via melt blending/compounding method using a Laboratory Mixing Extruder (LME). The effect of PVA fiber concentrations (i.e. 0, 5, 10, 20, 30 wt%) on the thermal properties (i.e. melting and crystallization) of the composites was investigated. The thermal properties of the composites were analysed using a Differential Scanning Calorimetry (DSC). The DSC analysis results exhibited that the presence of PVA fiber did not considerably change the melting and crystallization properties of the composites. The melting temperature (Tm) of all the composites samples were similar, which was in the range of 130 - 131 °C. The highest Tm was belong to sample PVAC-20 (i.e. 20 wt% PVA fiber). In the other hand, the crystallinity index (Xc) of the HPDE/PVA fiber composites decreased with the increase of PVA fiber concentrations. The Xc of the composites decreased from 56.7 % for PVAC-0 to 49.8 % for PVAC-20. Additionally, in term of crystallization behavior of the composites, the effect of PVA loadings on the crystallization temperature (Tc) of the composites was also not significant. The Tc of all composites samples were similar, which was about 115 °C. It can be suggested that the addition of PVA fiber did not affect the crystallization process of the matrix.


Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 68
Author(s):  
Hala Zahlan ◽  
Waseem Sharaf Saeed ◽  
Saad Alqahtani ◽  
Taieb Aouak

Poly(ethylene-co-vinylalcohol) (E-VOH) and carbon nanotube-filled poly (vinyl alcohol-co-ethylene) (E-VOH/CNT) were used as membranes to separate benzene/cyclohexane mixtures by pervaporation technique. To reach this goal, E-VOH and E-VOH/CNT membranes were prepared by solvent casting method and characterized by differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The swelling tests were used to study the mass transfer of the benzene/cyclohexane mixture and their pure components. The separation by pervaporation process was carried out at 25 °C in which the effect of CNTs incorporated into E-VOH matrix and the initial concentration of benzene in the feed on the permeate flux, j, and separation factor, β, performance was investigated. The results obtained were very promising, in which the integration of CNTs through E-VOH chains increased the absorption area and raised the flux to 740 g/m2∙h. The separation factor increased to 9.03 and the pervaporation separation reached an index of 5942.2 g/m2∙h for the azeotropic mixture during 3 h of the separation process. In contrast, for the unfilled E-VOH membrane, it was found that these parameters were a rise of 280 g∙m−2∙h−1, separation factor of 12.90 and pervaporation separation index of 3332.0 g/m2∙h, under the same conditions. Likewise, the calculation of the performance of the E-VOH/CNT membrane with regard to that of the unfilled membrane indicated 2.64 for the total flux and 0.70 for the separation factor. It was also revealed that the best compromise of the filled membrane in terms of total cumulative flux and separation factor is obtained for the feed containing the azeotropic mixture.


2018 ◽  
Vol 773 ◽  
pp. 46-50 ◽  
Author(s):  
Achmad Chafidz ◽  
Umi Rofiqah ◽  
Tintin Mutiara ◽  
Muhammad Rizal ◽  
Mujtahid Kaavessina ◽  
...  

In the present work, high density polyethylene (HDPE)/poly (vinyl alcohol) (PVA) fiber composites with four different PVA fiber loadings (i.e. 0, 5, 10, 20 wt%) have been prepared via melt compounding method using a twin-screw extruder. The composites were characterized for their morphology by using a scanning electron microscopy (SEM). Whereas, the dynamic mechanical thermal analysis (DMTA) was carried out by using an oscillatory rheometer. The DMTA test was carried out under torsion mode using temperature sweep test on rectangular composites samples. The DMTA results showed that the storage modulus (G¢) of the composites were higher than that of the neat HDPE and increased with increasing PVA fiber loadings. This indicated that there was a considerable stiffness enhancement of the composites. For example, at temperature of 60°C, the increases of stiffness (i.e. storage modulus) of the composites were approximately 3, 31, and 54% for PVAC-5, 10, and 20, respectively. Whereas, at higher temperature (i.e. 120°C), the increases were about 4, 50, and 98% for PVAC-5, 10, and 20, respectively. These results indicated that even at higher temperatures, the enhancement of storage modulus of the composites was still high.


2011 ◽  
Vol 2 (4) ◽  
pp. 131-148 ◽  
Author(s):  
Francis Vidya ◽  
Subin S. Raghul ◽  
Sarita G Bhat ◽  
Eby Thomas Thachil

The main objective of this study was to enhance the rate of UV and biodegradation of polyethylene by incorporating biodegradable materials and prooxidants. Prooxidants such as transition metal complexes are capable of initiating photooxidation and polymer chain cleavage, rendering the product more susceptible to biodegradation. In this work, the effect of (1) a metallic photoinitiator, cobalt stearate, and (2) different combinations of cobalt stearate and vegetable oil on the photooxidative degradation of linear low-density poly(ethylene)-poly(vinyl alcohol) (LLDPE/PVA) blend films has been investigated. For this, film-grade LLDPE was blended with different proportions of PVA. PVA is widely used in the industrial field, and recently it has attracted increasing attention as a water-soluble biodegradable polymer. Cobalt stearate and vegetable oil were added to the blends as prooxidants. The blends were prepared by melt mixing in a Thermo HAAKE Polylab system. Thin films containing these additives were prepared by a subsequent compression moulding process. The effect of UV exposure on LLDPE/PVA films in the presence as well as absence of these additives was investigated. Tensile properties, FTIR spectra, and scanning electron microscopy (SEM) were employed to investigate the degradation behaviour. It was found


2016 ◽  
Vol 54 (13) ◽  
pp. 1217-1226 ◽  
Author(s):  
Ainhoa Lejardi ◽  
Jose-Ramon Sarasua ◽  
Agustin Etxeberria ◽  
Emilio Meaurio

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