scholarly journals Toughening of Poly(L-lactide) with Blends of Poly(ε-caprolactone-co-L-lactide) in the Presence of Chain Extender

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yaowalak Srisuwan ◽  
Yodthong Baimark ◽  
Supakij Suttiruengwong
Keyword(s):  
Impact Strength ◽  
Melt Flow Index ◽  
Chain Extender ◽  
Chain Extension ◽  
Flow Index ◽  
Melt Blending ◽  
Melt Flow ◽  
Phase Compatibility ◽  
The Impact ◽  
Reactive Melt

A poly(ε-caprolactone-co-L-lactide) copolyester was synthesized and employed to toughen poly(L-lactide) (PLLA) by reactive melt blending in the presence of an epoxy-based chain extender. The effects of chain extension reaction and copolyester content on properties of PLLA-based blends were studied. The chain extension reaction reduced crystallinity and melt flow index of PLLA/copolyester blends. Meanwhile the copolyester blending improved the crystallinities of the chain-extended PLLA up to 20 wt% copolyester. The phase compatibility between PLLA matrix and dispersed copolyester phases was enhanced by the chain extension reaction. The impact strength of chain-extended PLLA increased with the contents of copolyester and chain extender.

Renewable resources-based PTT [poly(trimethylene terephthalate)]/switchgrass fiber composites: The effect of compatibilization

2012 ◽  
Vol 85 (3) ◽  
pp. 521-532 ◽  
Author(s):  
Jeevan Prasad Reddy ◽  
Manjusri Misra ◽  
Amar Mohanty
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Renewable Resources ◽  
Melt Flow Index ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Flow Index ◽  
Methylene Diphenyl Diisocyanate ◽  
Trimethylene Terephthalate ◽  
The Impact

In this research, switchgrass (SG) fiber-reinforced poly(trimethylene terephthalate) (PTT) biocomposites were prepared by extrusion followed by injection molding machine. The methylene-diphenyl-diisocyanate-polybutadiene (MDIPB) prepolymer was used to enhance the impact strength of the biocomposites. In addition, the polymeric methylene-diphenyl-diisocyanate (PMDI) compatibilizer was used to enhance the mechanical properties of the composites. The effect of compatibilizer on mechanical, crystallization melting, thermomechanical, melt flow index (MFI), morphological, and thermal stability properties of the composites was studied. Thermomechanical properties of the biocomposites were studied by dynamic mechanical analysis (DMA). Scanning electron microscopy (SEM) was used to observe the interfacial adhesion between the fiber and matrix. The results showed that MDIPB and PMDI have a significant effect on the mechanical properties of the composites. The impact strength of MDIPB- and PMDI-compatibilized composites was increased by 87 % when compared to the uncompatibilized composite.

Comparison of Melt Flow and Mechanical Properties of Rice Husk and Kenaf Hybrid Composites

2013 ◽  
Vol 701 ◽  
pp. 42-46 ◽  
Author(s):  
Abd Aziz Noor Zuhaira ◽  
Rahmah Mohamed
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Rice Husk ◽  
Hybrid Composites ◽  
Natural Fibers ◽  
Melt Flow Index ◽  
Silica Content ◽  
Flow Index ◽  
Melt Flow

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.

Investigation the mechanical, rheological, and morphological properties of acrylonitrile butadiene styrene blends with different recycling number content

2017 ◽  
Vol 232 (4) ◽  
pp. 449-458 ◽  
Author(s):  
Ibrahim Hamarat ◽  
Emel Kuram ◽  
Babur Ozcelik
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Acrylonitrile Butadiene Styrene ◽  
Melt Flow Index ◽  
Morphological Properties ◽  
Flow Index ◽  
Melt Flow ◽  
Recycled Polymer ◽  
Recycled Material ◽  
Butadiene Styrene

In this study, acrylonitrile butadiene styrene polymer was exposed to 12 injection cycles to investigate the influence of recycling number on the mechanical, rheological, and morphological properties. Also, binary and ternary blends including different weight percentages and recycling number of virgin–recycled polymers were prepared. A slight decrement was found in the tensile strength values with recycling number. All blends including recycled polymer (binary or ternary) gave lower tensile strength values with respect to 100% virgin polymer. Strain at break value was decreased after twelve times recycling; however, no clear tendency was observed with the presence of different ratios of virgin polymer to recycled polymer. Impact strength of the polymer decreased with recycling number. There was relatively large drop in the third recycling, from 72 kJ/m2 to 38.5 kJ/m2; however, further recycling induced in a slower drop in the impact strength to 32.5 kJ/m2. All blends including recycled material gave lower impact strength values as compared to 100% virgin polymer. It was observed that the melt flow index values increased with the recycling number, a total of 26.53% after twelve times recycling. All blends containing recycled material showed higher melt flow index values as compared to 100% virgin polymer.

scholarly journals Improvement in Crystallizability and Melt Flow Property of Linear Poly(L-lactide) Bioplastic by Blending with Star-shaped Poly(L-lactide)

2018 ◽  
Vol 34 (4) ◽  
pp. 1878-1883 ◽  
Author(s):  
Yodthong Baimar ◽  
Yaowalak Srisuwan
Keyword(s):  
Flow Property ◽  
Nucleating Agent ◽  
Chain Extender ◽  
Chain Extension ◽  
Melt Blending ◽  
Melt Flow ◽  
Blend Ratio ◽  
Melt Strength ◽  
Blend Films ◽  
Linear Poly

This research focuses on the crystallizability and melt flow property of linear poly(L-lactide) (1-PLL) by blending with star-shaped 16-arm PLL (16-PLL). The 1-PLL/16-PLL blends were chain extended during melt blending using an epoxy-based chain extender. The crystallinities of the 1-PLL/16-PLL blends increased with the 16-PLL blend ratio and chain extension reaction. The 16-PLL enhanced formation of branched PLL during chain extension was confirmed by thermogravimetry, and improved the melt flow property of the blends. Stresses at break of the compressed blend films were improved slightly by the 16-PLL blending and chain extension. In conclusion, the 16-PLL could be used as a nucleating agent and a melt strength enhancer for linear PLL.

Thermal and mechanical properties of highly flexible poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) bioplastics: Effects of poly(ethylene glycol) block length and chain extender

2019 ◽  
Vol 52 (2) ◽  
pp. 142-158 ◽  
Author(s):  
Yodthong Baimark ◽  
Yaowalak Srisuwan
Keyword(s):  
Ethylene Glycol ◽  
Chain Extender ◽  
Chain Extension ◽  
Block Length ◽  
Melt Blending ◽  
Poly Ethylene Glycol ◽  
Lower Stress ◽  
Practical Applications ◽  
Poly Ethylene ◽  
Reactive Melt

The brittleness of poly(L-lactide) (PLLA) bioplastic is the main disadvantage for practical applications. Herein, we report the synthesis of high-molecular-weight PLLA- b-poly(ethylene glycol)- b-PLLA (PLLA-PEG-PLLA) block copolymers by ring-opening polymerization of LLA. The highly flexible PLLA-PEG-PLLAs were prepared by reactive melt blending with an epoxy-based chain extender formed as long-chain branched structures. The effects of PEG block length and content of chain extender were investigated. The results showed that the chain extension reaction reduced crystallinities of the PLLA-PEG-PLLAs. All the chain-extended PLLA-PEG-PLLA films had no phase separation. The lower crystallinities of PLLA-PEG-PLLA films obtained with higher contents of chain extender enhanced the film drawability. The longer PEG block length resulted in higher strain at break and lower stress at the break of PLLA-PEG-PLLA films. These chain-extended PLLA-PEG-PLLAs have potential for use as highly flexible bioplastics.

scholarly journals РОЗРОБКА НАПОВНЕНИХ ПОЛІОЛЕФІНОВИХ КОМПОЗИЦІЙ ДЛЯ ЛИТТЄВИХ ВИРОБІВ

2020 ◽  
Vol 140 (6) ◽  
pp. 95-103
Author(s):  
С. В. Сайтарли ◽  
В. П. Плаван ◽  
Л. С. Дзюбенко ◽  
О. С. Керенівський ◽  
Д. М. Євдокименко
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Injection Molding ◽  
Frost Resistance ◽  
Melt Flow Index ◽  
Production Costs ◽  
Flow Index ◽  
Melt Flow ◽  
Polyolefin Elastomer

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.

Effects of Calcium Carbonate on Melt Flow and Mechanical Properties of Rice Husk/HDPE and Kenaf/HDPE Hybrid Composites

2013 ◽  
Vol 795 ◽  
pp. 286-289 ◽  
Author(s):  
Abd Aziz Noor Zuhaira ◽  
Mohamed Rahmah
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Impact Strength ◽  
Rice Husk ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Melt Flow Index ◽  
Flow Index ◽  
Test Results ◽  
Melt Flow

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.

scholarly journals Preparation of Stereocomplex Polylactide/Poly(Butylene Succinate) Blends by Melt Blending

2019 ◽  
Vol 35 (3) ◽  
pp. 958-965 ◽  
Author(s):  
Jenjira Jirum ◽  
Yodthong Baimark
Keyword(s):  
Amorphous Region ◽  
Chain Extender ◽  
Chain Extension ◽  
Melt Blending ◽  
Butylene Succinate ◽  
Blend Films ◽  
Thermal Phase ◽  
A Chain ◽  
Phase Compatibility ◽  
Thermal Stability Of

Biodegradable polymer blends based on stereocomplex polylactide (scPLA) and poly(butylene succinate) (PBS) were successfully formed by continuous two-step melt blending. An epoxy-based, multifunctional chain extender was chosen to enhance phase compatibility of the blends. Effects of PBS and chain extender on thermal, phase morphology, thermo-mechanical and tensile properties of the scPLA/PBS blends were determined. The PBS blending enhanced plasticizing effect and cold-crystallization of scPLA matrix in an amorphous region. The chain-extension reaction inhibited crystallization of PBS, PLA homo-crystallites and PLA stereocomplex-crystallites as well as reduced thermal stability of the scPLA/PBS blends because of formation of long-chain branched structures. It has been shown that the poor phase compatibility between continuous scPLA and dispersed PBS phases of the blends may be solved through melt blending with a chain extender. The chain extension of scPLA/PBS blends also improved thermo-mechanical properties and flexibility of the scPLA/PBS blend films.

scholarly journals Investigation of Melt Flow Index and Impact Strength of Foamed LLDPE for Rotational Moulding Process

2014 ◽  
Vol 6 ◽  
pp. 361-367 ◽  
Author(s):  
P.L. Ramkumar ◽  
D.M. Kulkarni ◽  
V.V.R. Abhijit ◽  
Aditya Cherukumudi
Keyword(s):  
Impact Strength ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Rotational Moulding ◽  
Moulding Process
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