Styrene grafting onto a polyolefin in an internal mixer and a twin-screw extruder: Experiment and kinetic model

2001 ◽  
Vol 41 (7) ◽  
pp. 1238-1250 ◽  
Author(s):  
Jaehyug Cha ◽  
James L. White
Keyword(s):  
Kinetic Model ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Twin Screw ◽  
Internal Mixer ◽  
Grafting Onto

Properties of EPDM/PP thermoplastic vulcanizates produced by an intermeshing-type internal mixer comparing with a co-rotating twin-screw extruder

2019 ◽  
Vol 39 (2) ◽  
pp. 143-151
Author(s):  
Wattana Teppinta ◽  
Banja Junhasavasdikul ◽  
Nattapong Nithi-Uthai
Keyword(s):  
Shear Rate ◽  
Elastic Recovery ◽  
Mechanical Energy ◽  
Cross Linking ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Lower Shear ◽  
Twin Screw ◽  
Lower Shear Rate ◽  
Internal Mixer

Abstract A unique technology for producing thermoplastic vulcanizate (TPV) has been developed using an intermeshing-type internal mixer (ITM). TPV produced by the ITM was compared with that produced using a co-rotating twin screw extruder (Co-TSE) to assess the former’s commercial possibilities. TPV, originating from ethylene-propylene-diene monomer (EPDM) and polypropylene (PP), was produced by both machines with equal filled volumes, same shear rate, and same specific mechanical energy. Results indicate that ITMs can be used to produce TPV with mechanical properties comparable to those of TPV produced by Co-TSE. TPV can be produced with a lower shear rate with ITM compared to Co-TSE. A long residence time can be maintained in the mixing chamber of the ITM, allowing high conversion of the cross-linking reaction and resulting in better elastic recovery properties due to the higher cross-linking density. However, this resulted in higher viscosity of TPV produced by ITM.

Reactive Blends of Poly(butylene adipate-co-terephthalate) and Thermoplastic Starch

2012 ◽  
Vol 488-489 ◽  
pp. 57-61
Author(s):  
Vorawan Arunyagasemsuke ◽  
Supakij Suttiruengwong ◽  
Manus Seadan
Keyword(s):  
Mechanical Properties ◽  
Weight Ratio ◽  
Cost Effective ◽  
Thermoplastic Starch ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Twin Screw ◽  
Reactive Blend ◽  
The Cost ◽  
Internal Mixer

The blend of poly(butylene adipate-co-terephthalate) (PBAT) and thermoplastic starch (TPS) are a promising way to get a new class of bio-compostible plastic, balance the cost effective issue and good mechanical properties. Blends of both polymers are immiscible in nature. Therefore, to make the blend to be more compatible, some block-copolymer compatibilizer can be introduced. Reactive blend is one of effective ways to create such compatibilization at the interface. The objective of this work was to study the reactive blends of PBAT/TPS in comparison to the physical blend. The reactive blends were prepared in both an internal mixer and a twin-screw extruder. For reactive blends in twin-screw extruder, PBAT, starch, glycerol and reactive agent were all pre-mixed and blended in an extruder on one step process. The weight ratio of PBAT:TPS (starch + glycerol) was fixed at 60:40. The reactive agent maleic anhydride (MA) and peroxide (Luperox® 101) were used at very low level 0-0.1 phr. The mechanical properties, morphology and flows property of blends were characterized using tensile machine, scanning electron microscope (SEM) and melt flow indexer (MFI). The internal mixer torque showed a decrease in a final torque value of TPS when MA being added, confirming the chain scsision reaction of TPS. The finer morphogy and better mechanical properties were obtained in the reactive blend with 0.1 phr of MA and 0.1 phr of peroxide.

The Effects of Melt Compounding Method on the Ambient and In Vitro Mechanical Properties of EVA/MMT Nanocomposites

2015 ◽  
Vol 789-790 ◽  
pp. 75-79 ◽  
Author(s):  
Azlin Fazlina Osman ◽  
Tew Wei Hong ◽  
Abdulkader M. Alakrach
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Melt Compounding ◽  
Twin Screw ◽  
Internal Mixer ◽  
Nanofiller Content ◽  
Eva Copolymer

The in vitro biostability of ethyl vinyl acetate (EVA) nanocomposite incorporating the organically modified montmorillonite (organo-MMT) was investgated as a new material for biomedical applications. The effects of compounding process and filler loadings on the ambient and in vitro (exposed in oxidizing condition, 37°C) mechanical properties were studied. We have observed that, the melt compounded EVA copolymer by internal mixer (Brabender plasticoder) achieved the highest ambient and in vitro mechanical properties at low nanofiller content (1wt% organo-MMT). In contrast, the melt compounded EVA copolymer by twin screw extruder achieved the highest ambient and in vitro mechanical properties at high nanofiller content (5wt% organo-MMT). We suggest that this was due to the capability of the twin screw extruder to provide greater shear force for the exfoliation and dispersion of the high content organo-MMT as compared to internal mixer (Brabender plasticoder). However, compounding by twin screw extruder caused more severe reduction in tensile toughness of the EVA containing 5 wt% organo-MMT, after this material was exposed to oxidative agent, 37°C. These studies show that the melt compounding method may bring significant effect to both the ambient and in vitro mechanical performance of the EVA nanocomposites, and hence further investigation towards optimization should be pursued.

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