Posts Tagged ‘crosslinking’

What Is thermoplastic polymers and in what ways are Nexam Chemical improving the properties of the materials? One methodology will be described in this blog post.

A multitude of our popular plastics are defined as thermoplastics which means that upon recycling , their molecular properties does not change as the plastic is melted and reused (according to definition and in theory). Examples are PE, PP, PTFE (Teflon), ABS and polyamide (nylon).

A very easily digested full pedagogic description is available here:

https://sciencing.com/thermoplastic-polymer-5552849.html

Another example of a thermoplastic is PET (polyethyleneterephtalate) which is used in composite sandwich constructions and light weight construction materials. The company Armacell is active in this business with sustainability in focus (recycling of PET bottles):

https://local.armacell.com/en/armaform-pet-foam-cores/

CESI has already highlighted that according to the Q2 Nexam Chemical interim report, Armacell will use Nexam proprietary technology in the next generation PET foam:

“The delivery agreement that we signed with Armacell last quarter is about to, with some delay, find its practical form. Armacell will use NEXAMITE® in its ArmaFORM® PET-foam to achieve increased efficiency” Source link. Statement found on page 2.

The explanation to the repeated CESI highlight is the following finding: A new Nexam patent application was published a few days ago (November 22, 2017). The described invention relates to a process for increasing the melt strength of a thermoplastic polyester and to mitigate degradation of the polyester during melting.

The common (?) degradation issues of PET is pedagogically described in this open access article by Venkatachalam et. al.:

“The main degradations that can occur include thermal degradation, oxidative degradation and hydrolytic degradation. Radiation induced or photo degradation leading to free radical reactions and enzymatic catalysed reactions leading to logical degradation are also possible. In addition to these there can be chemical degradation reaction of polyester initiated by specific chemicals like glycol, ammonia or amines or other such reagents. Besides these there can be weathering ageing which could be the combined effect of exposure to temperature, moisture, chemical, UV and visible light and other conditions such as exposure to grease, oil. Polyester can also undergo stress induced degradation reactions when subjected to mechanical stress. The degradation of polyester can lead to several changes in the articles made out of the polymer. These changes include discoloration, chain scissions resulting in reduced molecular weight, formation of acetaldehyde and cross-links or gel formation and fish-eye formation in films.
The thermal and thermo oxidative results in poor processibility and performance
characteristics in the products. Discoloration is due to the formation of various
chromophoric systems following prolonged thermal treatment at elevated temperatures.
This becomes a problem when the optical requirements of the polymer are very high, such as in packaging applications.”

Let´s look at some quotes from the following new Nexam patent application…

EP3246349 PROCESS FOR INCREASING THE MELT STRENGTH OF A THERMOPLASTIC POLYMER

Publication Date:22.11.2017

Applicant: Nexam Chemical AB

Source link here (most easily digested if downloaded)

“However, especially thermoplastic polyesters, but also to some extent aliphatic polyamides, suffer from having a narrow processing window, thereby typically requiring specialized processing equipment. This is related to the melt rheology of thermoplastic polyesters. Thermoplastic polyesters typically have low melt viscosity, low melt strength, and low melt elasticity.”

[CESI: see blue font below for “rheology” explanations]

“[0012] By using PETA, rather than pyromellitic dianhydride (PMDA) commonly used in the art, the melt strength of thermoplastic polyesters could be considerably increased. By use of the same combination, i.e. PET A and a bisoxazoline, also the melt strength of polyamides, e.g. aliphatic polyamides, and thermoplastic polyurethanes, could be improved.

[0013] Further and importantly, the rate of the thermomechanical degradation seen in melt mixing of thermoplastic polyesters was considerably decreased compared to PBO/PMDA-systems, as can be seen from Fig. 1. For applications with longer residence times, such as residence times exceeding 10 minutes, this is a clear advantage, as the thermomechanical degradation is quite rapid for PBO/PMDA-systems. A typical example of an application with longer residence time is extrusion foaming of PET. polyesters was considerably decreased compared to PBO/PMDA-systems, as can be seen from Fig. 1.

CESI:  Nexam specify a large number of polyester polymer substrates and additives:

“According to an embodiment, the thermoplastic polymer is thus a polyester. The polyester is typically an aliphatic polyester or a semi aromatic polyester. The polyester may be selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), 30 polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), and polyethylene naphthale (PEN). Specifically, the polyester employed may be a semi aromatic polyester. Examples of aliphatic polyesters include polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), polyethylene adipate (PEA), and polyhydroxyalkanoate (PHA), e.g. poly-3-hydroxyvalerate (PHV), poly-4-hydroxybutyrate (P4HB), and poly-3-hydroxy propionate (P3HP). Examples of semi aromatic polyesters include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene 35 terephthalate (PPT), polybutylene terephthalate (PBT), and polytrimethylene terephthalate (PTT). Further, the semiaromatic polyester may be a co-polymer of PET, PBT, or PEN.

Thus, also a nucleating agent, such as talc, kaolin, silica gel, orTi02, a flame retardant, such as a halogenated, charforming (like phosphorus-containing) or water-releasing compound, a plasticizer, a lubricant, such as an ester of a fatty acid, an impact modifier, insulation modifier, a pigment, a filler, an antioxidant, a UV-stabilizer and/or a color improver may be added to the thermoplastic polymer and melt mixed therewith.”

Fig 2 visualizes (see graph in link here) that…

At high frequencies> 100 rad/s (i.e. at high shear rate) the differences between the different formulations is relatively small, whereas at low frequencies <1 rad/s (i.e. at low shear rate) the complex viscosity of the PETA-PBO formulation is approximately at least one order of magnitude higher than the comparative examples. Further, the cross-over point, which was determined from the frequency sweep analysis, was significantly lower for Example 1 as compared to the Comparative Examples 1-4. Determination of cross-over point is a method used to evaluate the melt strength (ref J. Frankland, Plastics Technology Online 2013-05-28). Thus, the  melt strength of the PETA-PBO formulation is superior compared to that of the comparative examples. Further, this confirms that pressure in the extruder may be used as a semi-quantitative measure of the melt strength, as the shear rate in the current experiments is about 6 rad/s in the extruder

The claim comprehends a number of polymides: PA6, PA 11, PA 12, PA46, PA41 0, 50 PA66, PA61 0, PA612, PA 1010, PA 1012, and PA 1212.

[CESI: Again, a polyamide is equivalent to nylon: https://en.wikipedia.org/wiki/Nylon]

And interestingly, the following article are stated in the final section of the patent application as a “document considered to be relevant”:

https://www.ptonline.com/articles/additives-multi-purpose-modifiers-pump-up-properties-of-virgin-recycled-plastics

Furthermore, the Armacell patent EP 2 163 577 A1 is exemplified.

In the ptonline link attached above,  a very interesting picture demonstrating the (potential) impact of Nexam technology is found (Nexam treated polymer vs untreated)

About Rheology- the science of deformation and flow of materials

Explanation of the unit rad/s found in the Nexam Chemical melt strength comparison plot:

  • Wikipedia (“shear rate unit” search): The SI unitof measurement for shear rate is s−1, expressed as “reciprocal seconds” or “inverse seconds
  • Wikipedia (“rad/s” search): In physics, the angular velocity of an object is the rate of change of its angular displacementwith respect to time. The SI unit of angular velocity is radians per second.

CESI Conclusion: It´s simply the frequency/velocity of the flow expressed in a more complicated way. Thus, it should directly correlate to the speed of the extrusion (the continuous manufacturing of plastics)

The link below describes fundamentals of Rheology in a pedagogic way: http://www.polydynamics.com/Rheology.pdf

CESI Learnings:

  • The higher the shear rate, the easier it is to force polymers to flow through dies and process equipment.”
  • When a force is acting tangentially on a surface, the corresponding stress is referred to as shear stress. Normal stress (=normal pressure) = when a force is perpendicular to a surface
  • Viscosity = Shear stress / shear rate (= a higher shear rate equals a lower viscosity)
  • Shear rate = Velocity / h (hight in the case of flow through 2 planes)
  • With careful rheological measurements, it is possible to determine whether, or under what conditions, a material will be processable. Blend ratios, or additive quantities necessary to facilitate processing can be determined. Many problems can be avoided by a thorough rheological characterization, before the material is introduced into the extruder hopper
  • With careful rheological measurements, it is possible to determine whether, or under what conditions, a material will be processable. Blend ratios, or additive quantities necessary to facilitate processing can be determined. Many problems can be avoided by a thorough rheological characterization, before the material is introduced into the extruder hopper

CESI rheology conclusion: So, rheology tells us that increased velocity (flow speed) will generally be beneficial for polymer processing up to the point shark skin (surface mattness) and melt fractures occurs as described in the article above.

In this patent application, Nexam demonstrate how melt strength can dramatically be increased even during slower speed (frequences,velocities, rad/s) and slow speed seems crucial for PET foam production and most importantly: The improvement is substantial – a full magnitude at < 1 rad/s (see page 14 here). The X axis unit “rad/s” was explained above (= frequency/ velocity/speed of the extrusion)

Thus, it seems that Nexam has solved/improved the melt strength in the “difficult slow extrusion PET foam case” by adding to Nexam product molecules that in fact result in a synergy effect As the key is to keep a high melt strength for an extended period of time as described here in the Nexam patent application quote:

[0058] Whereas system comprising PMDA or combinations of PMDA and PBO also are effective in reacting with PET to increase the melt strength (measured as increased pressured in the extruder), these systems are prone to quite rapidly cause degradation. For longer residence time, such as the ones typically used in e.g. foaming application, the final melt strength is thus significantly lower (cf. Fig. 1 and Table 4). However, as can be seen from Fig. 1 and Table 4, systems comprising combinations of PETA and PBO, may provide increased melt strength also for longer residence times as the melt strength declines far less rapidly. As can be seen in Fig. 1 for the PMDA, PMDA+PBO and PBO formulations, 20 the pressure reaches its maximum value in < 10 minutes and after that, it decreases with increasing time. For the PETA+PBO, on the other hand, the maximum pressure is obtained after> 10 minutes. Also, for the PETA+PBO formulation the pressure at the end of the experiment is significantly higher than for the comparative examples

The opposite easy case is the following scenario described at page 3 here: http://www.polydynamics.com/Rheology.pdf

“One remarkable property of polymeric liquids is their shear-thinning behavior (also known as pseudo-plastic behavior). If we increase the rate of shearing (i.e., extrude faster through a die), the viscosity becomes smaller [….] This reduction of viscosity is due to molecular alignments and disentanglements of the long polymer chains. As one author said in a recent article: “polymers love shear.” The higher the shear rate, the easier it is to force polymers to flow through dies and process equipment.”

Best regards, CESI

(Not skilled in the art of polymer chemistry but with an ambition to continuously gain learnings…)

The author, Cutting Edge Science Invest, is a Nexam Chemical share holder. Cutting Edge Science Invest can not guarantee, or take into  accountability, the content of truth and accuracy of the information in this article/post.Thus, Cutting Edge Science Invest requires that a possible reader gather complimentary information if any type of investment in the company described above is considered. Cutting Edge Science Invest provides personally biased information and at best also “general information and opinions”. The article/post does not contain professional investment advice. 

After a long period of humble and neutral statements, the Nexam Chemical CEO currently sings in major key. With cash ~100 Million SEK, the songs seems trustworthy:

Disclaimer: Presentation in Swedish. See recent interim reports for hard facts. 

 

The recent audiocasts also contain a lot of interesting information:

https://tv.streamfabriken.com/nexam-chemical-q3-2017

https://tv.streamfabriken.com/nexam-chemicals-q2-2017

Not only within its own internal patent portfolio, but also within the public external patent application landscape, Nexam Chemical seems healthy:

Slide1

Despite continued delays from Armacell (commented above)…

02/22/2017

 

…substantial scientific leaps within the research pipeline (with subsequent external funding) has been taken by the CEO Anders Spetz during the year:

05/15/2017

 

This press release is conceptually very interesting as graphene is predicted to become the next industry “wonder material” [Source link]

Furthermore, within the presumable future Nylon business area that…

09/21/2017

 

…vibrates well with the sheer CESI speculation that Nylon crosslinking using Nexam proprietary molecules eventually will be a reality (in industrial scale). Within the Nylon area, BASF is still presumably a Nexam partner due to (CESI speculation again):

  • The patent application previously commented here [Source link]
  • The Statement from Nexam in the original press release announcing the exclusivity agreement termination: “The collaboration will however continue between the parties and test material based on BASF’s polyamide 66 and Nexam Chemical’s additives will be tested in components by e.g. the automotive industry” )

 

Very interestingly, Nexam also attracted interest from the electronics industry:

10/17/2017

Nexam Chemical will early next year start supplying material to a new Japanese customer within the focus area high performance polymers, and thereby opening a new high performance segment – solutions for semiconductors.

The customer, a leading Japanese manufacturer of semiconductor materials, has for a long time collaborated with Nexam Chemical to produce materials that meet the high standards of semiconductor encapsulation materials. Semiconductors are included in the components of most of the electronics we currently have around us, e.g. mobile phones, computers etc. As components become smaller, the demand on heat resistance have increased. Nexam Chemical has materials that fit well for these requests.

”So far we have been focused on high temperature composites in the high performance area. We now have a first customer within semiconductors and we see opportunities for interesting projects together with several players, which in in the long run can lead to business. Initially it is about smaller volumes, but with a potential to develop further. This is a new exciting area where Nexam Chemical’s technology can create value for the material manufacturers” says Anders Spetz CEO at Nexam Chemical.

“The interest from the companies developing semiconductors is mainly based on that Nexam Chemical´s material and products enable curing at lower temperatures. The polymeric materials included in the semiconductors are cured in a later stage of the manufacturing process and therefore needs to be done at a lower temperature so that other parts are undamaged. As the industry moves towards smaller and smaller components, the temperature in the components are often higher during usage. Therefore, temperature-resistant materials like polyimide are needed. However, polyimide must normally be cured at fairly high temperatures, but with the help of NEXIMID®, the temperature can be reduced with up to 100 degrees Celsius. A significant difference” says Masaki Shimada at Kadotoku, Nexam Chemical´s distributor in Japan.

Another proof of principle of valuable product molecules is the announcement that Maverick has placed a first decent size order. Maverick is a producer of high temperature polyimide resins for the aerospace industry

0/26/2017

Nexam Chemical has received an order from Maverick with a value amounting to approximately SEK 5.3 million for NEXIMID®. The order will delivered according to call-off from the customer during 2018.

NEXMID® can be used to manufacture polyimide resin, which is an essential component in temperature resistant composites. Composites containing NEXIMID® is used in environments where extensive material stress and high temperature put extreme requirements on the material. The application area is mainly within advanced aircraft, space and other areas where the performance requirements on the materials are the highest.

“The order from Maverick is a confirmation that our solution add high value and that we have a strong offer within the high performance area. We are happy to see an increase in the order volume, which is promising for the future and we continuously work with the customer to provide new solutions that can generate additional value to their growing business”, says Anders Spetz, CEO.

Most importantly, new evidence that Nexam product molecules are viable is the following important press release. Despite the initial small order, this order should be defined as a proof of concept order:

11/07/2017

Diab, a global leader within core materials for various types of demanding composite constructions has placed its first major order of NEXAMITE®-based masterbatch. The order value amounts to approximately SEK 600 thousand and delivery will take place during the fourth quarter.

 

The launch of high performance PET-foam has started, with NEXAMITE®-technology forming an essential part. The PET-foam contains Nexam Chemical’s property enhancing additive NEXAMITE®, delivered in masterbatch formulation. Using NEXAMITE® in masterbatch formulation simplifies customers production process and secures a consistent product quality in the customers existing production equipment.

“I am very pleased that we now see the results from our development cooperation with Diab. It is a commercial breakthrough order for Nexam Chemical within the area PET-foam and I am convinced that we together with Diab has developed really strong products, relevant for solar and wind energy, automotive and transport solutions, as well as advanced building constructions. We look forward to a continued good cooperation with Diab,” says Anders Spetz, CEO at Nexam Chemical.

Of great importance is the following detail: Nexam is able to deliver already during Q4.

Another milestone that not yet has solidified financial impact is the following announcement:

11/15/2017

Nexam Chemical has received a first order from one of the leaders within high performance PET-foam. The order value amounts to approximately SEK 400 thousand and will be delivered during the fourth quarter.

Nexam Chemical develops and manufacture property enhancing additives under the brand NEXAMITE®. NEXAMITE® is delivered in a pre-blended mix, a so-called masterbatch. Through masterbatch NEXAMITE® can be added to customers’ existing production equipment, which simplifies the production process and ensures a high and stable product quality. This is the third leading company within PET-foam manufacturing that Nexam Chemical deliver masterbatch to.

“It is very pleasing to see that our determined work now start to become fruitful. The customer has tested our products for some time and we have now been trusted in delivering the first volume going directly into their production of high performance PET-foam. We look forward to further deepen our cooperation for increased volumes in the future,” says Anders Spetz, CEO at Nexam Chemical.

Additional CESI blog posts are available here [Source link]. Personally, CESI is most interested in the PE pipe business segment reviewed here [Source link]

CESI has also refreshed his memory by re-reading all previous interim reports. A collection of information defined as interesting is attached below:

Slide2Slide3Slide4Slide5

And worth highlighting is also the namned partner in the recent successful MATPAX project:

11/14/2017

MATPAX, a two year Eurostars/Vinnova funded collaboration project between Nexam Chemical and two European project partners, has been completed according to plan. The aim was to develop new polyamide resins and a new manufacturing process with the goal to address light weight applications within, for example the electronic and automotive industry. Based on the positive results so far, the partners have agreed to further develop the technology.

The main focus of the project was to develop a system solution comprising a tailored resin, with embedded reactive functionality (cross-linkers), and a production process to manufacture crosslinked parts from this resin. The test results displayed significantly enhanced mechanical properties. These results create opportunities for new applications where, for instance product performance could be retained in parts made with less material than existing products – enabling weight reduction.

“The MATPAX-project was successful and the participants are optimistic about this technology. We are developing a new solution with an interesting future and we have gained a lot new knowledge about plastics materials development”, says Dane Momcilovic, CTO.

For more information about the project visit www.vinnova.se (only in Swedish). Nexam Chemical has received half of the project cost as contribution from Vinnova. Total contribution received during the project amounts to approximately SEK 2.4 million.

Partner info:

http://www.emsgrivory.com/en/about-ems-grivory/about-ems-grivory/ems-grivory-at-a-glance/

EMS Grivory product overview:

http://www.emsgrivory.com/en/products-markets/products/product-overview/

Best regards, CESI

The author, Cutting Edge Science Invest, is a Nexam Chemical share holder. Cutting Edge Science Invest can not guarantee, or take into  accountability, the content of truth and accuracy of the information in this article/post.Thus, Cutting Edge Science Invest requires that a possible reader gather complimentary information if any type of investment in the company described above is considered. Cutting Edge Science Invest provides personally biased information and at best also “general information and opinions”. The article/post does not contain professional investment advice.