Material and Product Development

Vibriso   The aim of material and product development is to design a wide range of structural composite polymers with different properties and a wide range of applications. The aim is to provide guidance in the light of accumulated experience on the principles followed in the design and R&D activities of these materials, which have a very wide potential for use in construction, machinery, automotive, electrical-electronics, defense industry, aviation, maritime, rail systems, biotechnology, engineering, in short, in every field related to the discipline of materials science, and to create a sharing platform as wide as possible in the relevant field. All information about the concepts mentioned in the articles is the result of our experimental observations.



The Importance of Elastomers as Flexible Structural Materials  

Materials science is a field of science that studies all chemical and physical properties such as structure, behavior, function and usefulness of all kinds of organic or inorganic materials such as metals, ceramics, polymers and composite materials that have the potential to be used in industry. According to their application areas, all structural materials are expected to exhibit properties specific to them and their tasks. These physical properties can take different forms such as hardness, flexibility, resistance to chemicals, thermal resistance, impact resistance, resistance to radiation and UV rays, adhesion strength or non-adhesion to any surface. In this special group, which we will call elastomers, we can list structural materials that exhibit a certain amount of regeneration when deformed under a force. Rigid and inflexible structural elements, which are frequently subjected to impacts, extinguish the energy by forming microcracks on them and thus become unable to resist the continuous accumulation of damage, disintegrate and become unable to perform their duties. Elastomeric materials, on the other hand, generally extinguish the destructive energy accumulations caused by movement at the connection, compression or collision points of moving parts by stretching and find application in providing flexibility to materials used in environments exposed to such events. In such cases, elastomer materials are much more long-lasting than inelastic ones. When analyzed in terms of costs, it is seen that while the cost of raw materials and processes used remains almost constant, the R&D costs required to design materials in full compliance with the desired properties create some disadvantage. However, considering the long-term stability of quality and long-lasting products, the importance of R&D activities in the design of appropriate materials in material science will stand out one step further.

Use of polyurethanes and polysulfides in the production of elastomers  

Considering their structural properties, polyurethanes are frequently used in elastomer production as they offer many options in their design. Polyurethanes are obtained by chain reaction of a wide variety of polyols and isocyanates. The wide variety of raw materials used provides convenience in elastomer designs. Polysulfides are used where both high flexibility and chemical resistance are sought together with ease of application. The design of materials for all the structures mentioned should be based on the purpose for which they are used, the physical conditions to which they will be exposed and, in most cases, on internationally recognized standard product specifications that specify these properties.

Product Design  

Material design is the creation of the formulation and production process techniques of the material by taking into account important features such as the area of use of the material, its performance in this area, and the physical conditions it will be exposed to. These techniques include the identification of a complete production process, such as raw material input control, formula and process control, product quality control, packaging, storage and shipment.

1 • Which product?  

Product design starts with the identification of the target material. Although it may seem like the most important step of the design process, how to actually do product identification is beyond the scope of this article. In a nutshell, this step examines whether a product is worth producing. The most important parameters for this are the demand for the product in the market, its availability and profitability. For example, if a product is only imported from abroad and, according to the analysis, is in demand in the market even at very high prices, it may seem very logical to produce it domestically employing domestic capital. Designing and producing such products is a very important task for our economy in terms of the development and prosperity of the country and reducing dependence on foreign countries. Products that are currently produced domestically but are monopolized may also be preferred for similar reasons. The selection of the product to be designed can also be made simply because it falls within the scope of our field of activity.

2 • Where and How will it be used ?  

The area of use of the relevant material, its performance in this area, and the physical conditions it will be exposed to are the most important features to be considered in the design. How the material is applied tells us what we need to design the way the end product is used. What the material is exposed to determines its lifespan. The answer to the question of what performance is expected from the material will determine the choices we will make in design in a very wide area. This means that we directly choose the polymer from which the system to be used will be made.

3 • Is there a product standard ?  

There are specifications published by standard organizations such as TSE, EN, ASTM, BRITISH for products generally used in industry and construction sector. Standard specifications include the physical and chemical properties of the product, as well as the way the product is presented to the customer, and the requirements are binding only on manufacturers who claim to produce in accordance with the standard. Standards actually guide us in a way in product design. It provides resources on how the material's hardness, flexibility, elongation, tear, fracture, impact resistance, chemical resistance, adhesion, conductivity, thermal expansion, curing speed, trafficability, and many other properties that vary from material to material should be and, most importantly, how to measure them. If possible, all standard documents about the material being designed should be provided. These are available for a fee from the relevant standardization body. There are two types of standards. The first is product-specific or product group-specific standards in which the technical specifications of the product are published The second is the experimental method standards, which describe how to perform the tests included in the first type of standards. When compiling the standards for a product, the method standards to which these standards refer, and even the standards in the third group, where the definitions of the test instruments used in the methods are made, should also be provided.

4 • Are there any competitor products ?  

Foreign products in the market where the product will be sold should be procured and checked whether they pass the tests in the relevant standards. What I often find is that products that claim to have a certain standard in the market actually pass some of the tests in the standard and fail others. This will also enable you to gain the ability to perform the tests specified in the standard in a methodical manner. Because most of the time you need to have acquired the ability to test to standard before, not during, your own product design process. The reason for procuring a competitor product is not only to perform its standard tests. Analyzing a competing composite polymer, prepolymer or liquid blend is crucial to give yourself a starting point. You can obtain important clues about the composition of the competitor product by performing the following tests in order in the competitor product analysis. Our basic approach here is to use the simplification method.

5 • Ash determination (filled component)  

You calculate the amount of inorganic filler in the structure by precise weighing at 500-1000ºC temperatures at intervals of 2-4 hours and by burning the organic parts of the material. You can determine the type of filler from the change in the weight of the filler material in weighings taken at 500-1000ºC. You can find the types of fillers that are commonly used by treating the filler you have in pure form with acids.

6 • Volatile content determination (both components)  

By calculating the weight loss of materials kept at 120ºC for 2 hours and then at higher temperatures for a period of time, the amount of solvent and other volatile materials, if any, in the material can be understood.

7 • Distillation under vacuum (both components)  

By applying some heat to the material under high vacuum, the exact solvents used can be determined from the odors and infrared spectra of the distillates collected at different temperatures.

8 • Non-volatile liquid fraction analysis (both components)  

The material is thoroughly diluted with some organic solvent, preferably toluene, to reduce its viscosity. It is then centrifuged to obtain the polymer portion which is extracted into the upper liquid phase. After all volatiles are removed from the material heated under vacuum, the remaining liquid part contains polymer mixture and additives. This mixture can be separated in HPLC chromatography and analyzed qualitatively and quantitatively by obtaining IR spectra individually.

9 • OH number determination (PU filled component)  

If the liquid part is obtained precisely, the equivalence of the polyurethane part can be calculated by determining the OH number. However, this complete separation is not an easy task.

10 • NCO number determination  

The equivalence of both components by weight can be found by determining the isocyanate (NCO) number in the isocyanate component instead of calculating equivalence by OH number determination. IR spectra of components A and B: The IR spectrum is an excellent and simple method to understand the structure of organic materials. In this way, we can easily recognize whether a material is Polyurethane (PU), Epoxy (EP), Polysulfide, Polyol, Isocyanate (NCO), Amine (NH). You can also understand whether these substances used in the material are aromatic or aliphatic.

How Should First Trials Be Conducted ?  

In the light of the above-mentioned standards and examinations of the competitor product, primary formulations are made with the same amount of fillers, the same polymers and the estimated amounts of catalysts and plasticizers that can give the same reaction rate, and additives that can stabilize these fillers, and curing is ensured. Before conducting all standard tests, certain properties are examined, such as hardness, flexibility, adhesion and rate of reaction (hardening). Some of these features will be close to what is specified in the standard and some will be far from it. In this case, we will need to go back to our formula and make changes to bring the property closer to the value it should be. In this case, instead of making a single change, a series of experiments shall be arranged. In this series, only one change is made at varying intensities and the resulting samples are retested. In this series, usually a formula is determined that is very close to the desired value. The formula obtained is then fine-tuned with a new series of experiments if necessary. When a basic property, such as hardness or flexibility, is brought closer to the value specified in the standard, many other properties will automatically approach the desired values. However, properties related to the application and presentation of the material, such as viscosity, thixotropy and color, will affect the final physical performance to a lesser extent and should be addressed separately and fine-tuned through serial tests.

Can we start all standardized tests ?  

If certain basic properties of the material have been fine-tuned through a series of experiments, we can start subjecting our best samples to all the standard tests. As a result of these tests, the defective features should be identified and the formula should be tried to be finalized. Knowing that we probably have a formula that is very close to the desired one, we can take small steps that will bring us closer to the desired property without making drastic changes, so that the formula meets all the specifications in the standard. As a result of these steps, we create a product formulation that meets almost all of the standards by spending the optimum amount of time and effort, testing only as many times as necessary.

How to Determine the Production Process ?  

Now we have our product formula, but we need to redesign our production line according to this formula. Immediately before the raw materials enter the warehouses, input control tests are carried out to determine whether they meet the required specifications. The appropriate ones are approved and marked. They are transported to the production line, weighed and transferred to mixers or reactors. When designing the processes to be applied in the mixers, temperature, mixing time, mixing speed, distillation and water removal processes, if any, are determined, and if necessary, changes should be made in the mixer and reactor as required by the production method. Failure to do so can be very costly if a failed production is interrupted. Here, as a rule, a scale-up method may need to be applied. This means that a 1-2 kg sample, first prepared under laboratory conditions, is gradually tried to produce 100-1000-10000 kg without suddenly scaling up to 1-10 tons. As the scale increases, problems may arise that could not have been anticipated before. In a step-by-step scale-up process, problematic issues are resolved and a safe production method is determined. Unfortunately, due to the nature of the method, the entire production process cannot be determined until some quantity is produced. Up to this point, the product prototype is now brought to the mass production stage.

How to choose packaging ?  

Generally, when choosing the packaging, packaging types that are familiar to people who use and apply the product in the market are considered. By taking their opinions into consideration, more appropriate packaging forms can be developed. The point here is to protect the product from the external environment, transfer processes and the detrimental factors that may come from the packaging itself, and to focus on designs that can provide extra convenience during application. Efforts should be made to maintain an appropriate balance between these two situations, which may be in competition with each other.