Carboxyl terminated polyamide 12 chain extension by reactive extrusion using a dioxazoline coupling agent. Part I: Extrusion parameters analysis

2000 ◽  
Vol 40 (1) ◽  
pp. 263-274 ◽  
Author(s):  
Yvan Chalamet ◽  
Mohamed Taha ◽  
Bruno Vergnes
Keyword(s):  
Coupling Agent ◽  
Reactive Extrusion ◽  
Chain Extension ◽  
Polyamide 12 ◽  
Parameters Analysis

In situformation and compounding of polyamide 12 by reactive extrusion

2003 ◽  
Vol 90 (2) ◽  
pp. 344-351 ◽  
Author(s):  
A. Wollny ◽  
H. Nitz ◽  
H. Faulhammer ◽  
N. Hoogen ◽  
R. Mülhaupt
Keyword(s):  
Reactive Extrusion ◽  
Polyamide 12

Recycling of poly(ethylene terephthalate) by chain extension during reactive extrusion using functionalized block copolymers synthesized by RAFT polymerization

2018 ◽  
Vol 135 (42) ◽  
pp. 46771 ◽  
Author(s):  
Juan José Benvenuta-Tapia ◽  
Valeria Jordana González-Coronel ◽  
Guillermo Soriano-Moro ◽  
Isabel Martínez-De la Luz ◽  
Eduardo Vivaldo-Lima
Keyword(s):  
Block Copolymers ◽  
Ethylene Terephthalate ◽  
Raft Polymerization ◽  
Reactive Extrusion ◽  
Chain Extension ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

scholarly journals Rheological Study of Gelation and Crosslinking in Chemical Modified Polyamide 12 Using a Multiwave Technique

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 855 ◽  
Author(s):  
Dominik Dörr ◽  
Ute Kuhn ◽  
Volker Altstädt
Keyword(s):  
Molecular Weight ◽  
Reactive Extrusion ◽  
Gel Point ◽  
Side Reactions ◽  
Processing Temperature ◽  
General Tendency ◽  
Material System ◽  
Point Evaluation ◽  
Polyamide 12 ◽  
Chain Extenders

When processing particular polymers, it may be necessary to increase the molecular weight, for example, during polymer recycling or foaming. Chemical additives such as chain extenders (CE) are often used to build up the molecular weight during reactive extrusion. One issue of chain extenders, however, is that they can cause gelation or crosslinking of the polymer during processes with long residence times. This can lead to strong process fluctuations, undesired process shutdowns due to uncontrollable torque and pressure fluctuations and finally consistent material quality cannot be guaranteed. To measure and understand the reactivity between the polymer and the CE a rheological test can help. However, the standard gel point evaluation used for thermosets by examining the point of intersection of storage- and loss modules is not suitable, as this method is frequency-dependent. This study uses a multiwave rheology test to identify the gel-point more reliably. Both evaluation methods were compared on a polyamide 12 system, which is modified with an industrially relevant chain extender. The results show that the multiwave test can be applied on a chemical modified thermoplastic system and that the material system indicates a general tendency to crosslink. The frequency-independent gel-point evaluation shows that the gel-point itself is dependent on the processing temperature. Finally, it was possible to detect undesired side reactions, which are not recognizable with the standard testing method. Both findings are directly relevant for the reactive extrusion process and help to understand the mechanism of gelation.

scholarly journals Mechanical Recycling of Partially Bio-Based and Recycled Polyethylene Terephthalate Blends by Reactive Extrusion with Poly(styrene-co-glycidyl methacrylate)

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 174 ◽  
Author(s):  
Sergi Montava-Jorda ◽  
Diego Lascano ◽  
Luis Quiles-Carrillo ◽  
Nestor Montanes ◽  
Teodomiro Boronat ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Glycidyl Methacrylate ◽  
Random Copolymer ◽  
Reactive Extrusion ◽  
Free Food ◽  
Extrusion Process ◽  
Chain Extension ◽  
Mechanical Resistance ◽  
Mechanical Recycling ◽  
Recycled Polyethylene

In the present study, partially bio-based polyethylene terephthalate (bio-PET) was melt-mixed at 15–45 wt% with recycled polyethylene terephthalate (r-PET) obtained from remnants of the injection blowing process of contaminant-free food-use bottles. The resultant compounded materials were thereafter shaped into pieces by injection molding for characterization. Poly(styrene-co-glycidyl methacrylate) (PS-co-GMA) was added at 1–5 parts per hundred resin (phr) of polyester blend during the extrusion process to counteract the ductility and toughness reduction that occurred in the bio-PET pieces after the incorporation of r-PET. This random copolymer effectively acted as a chain extender in the polyester blend, resulting in injection-molded pieces with slightly higher mechanical resistance properties and nearly the same ductility and toughness than those of neat bio-PET. In particular, for the polyester blend containing 45 wt% of r-PET, elongation at break (εb) increased from 10.8% to 378.8% after the addition of 5 phr of PS-co-GMA, while impact strength also improved from 1.84 kJ·m−2 to 2.52 kJ·m−2. The mechanical enhancement attained was related to the formation of branched and larger macromolecules by a mechanism of chain extension based on the reaction of the multiple glycidyl methacrylate (GMA) groups present in PS-co-GMA with the hydroxyl (–OH) and carboxyl (–COOH) terminal groups of both bio-PET and r-PET. Furthermore, all the polyester blend pieces showed thermal and dimensional stabilities similar to those of neat bio-PET, remaining stable up to more than 400 °C. Therefore, the use low contents of the tested multi-functional copolymer can successfully restore the properties of bio-based but non-biodegradable polyesters during melt reprocessing with their recycled petrochemical counterparts and an effective mechanical recycling is achieved.

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