:Plasticizers

Plasticizers are additives that enhance the flexibility and processability of plastics, preparing them for diverse applications. Among the extensive range of plasticizers, Di-Octyl Phthalate (DOP) is commonly used as a typical plasticizer.

:DOP Plasticizer

One of the primary functions of the DOP substance in Polyvinyl Chloride (PVC) products is to establish flexibility and softness. Achieving this characteristic necessitates an appropriate level of usage (above 5 P.h.r). DOP, in contact with the polymer chains, creates spaces or gaps between them. These gaps aid in reducing intermolecular forces among the polymer chains, allowing for easier movement and increased flexibility.

However, if the consumption dose of DOP significantly drops below 5 P.h.r, for example, in the range of 1-2.5 P.h.r, there might not be enough plasticizer to separate the polymer chains adequately. In this scenario, this lack of separation limits the movement of polymer chains, leading to increased intermolecular forces, consequently resulting in a harder material. Thus, maintaining an appropriate balance in the dosage of DOP plasticizer is crucial for achieving the desired material characteristics.

Additionally, the chemical structure of plasticizers plays a pivotal role in the properties of PVC compositions. The length of the carbon chain significantly impacts migration and environmental sustainability. Plasticizers with longer carbon chains migrate less, reducing biological contamination and soil and air pollution. Hence, shorter carbon chains lead to higher migration from PVC. This issue, especially in applications involving contact with food substances and medical concerns, has raised concerns prompting the necessity for the use of alternative plasticizers.

:Emergence of Alternatives

Continuing, we will delve into the examination of DOP oil and compare it with its alternatives:

1.DOTP

:Usage dose

(SF) SUNSSTITUTE FACTOR or “Substitution Ratio” is a term measuring the softening power of each plasticizer compared to DOP. This value remains a constant 1 for DOP. If the SF value exceeds 1, it implies the need for a higher quantity of plasticizer to achieve similar softening power as DOP, and vice versa. For instance, DOTP with a substitution ratio of 1.03 requires a slightly higher consumption to attain the softening power and similar properties to DOP.

:Health considerations

Polarity plays a key role in the migration of plasticizers. DOP and DOTP exhibit different levels of polarity.

:Polarity DOP

DOP is a phthalate-based plasticizer, and the presence of these groups leads to its relatively high polarity. Phthalate groups contain oxygen atoms with high electronegativity, creating a polar section in the molecule. The polar section of DOP increases its compatibility with the polar sections of PVC, resulting in a significant absorption of DOP into PVC and the creation of good flexibility.

:Polarity DOTP

DOTP, a terephthalate-based plasticizer, generally exhibits lower polarity compared to phthalates. The reduced polarity of DOTP compared to DOP reduces its compatibility with the polar sections of PVC. This means that DOTP may not be absorbed as significantly into PVC compared to DOP. Moreover, lower polarity in DOTP signifies lesser migration compared to DOP.

Therefore, a lower migration rate of the plasticizer is considered a more valid hygienic option. Consequently, due to its lower polarity, DOTP is perceived as a hygienic option in some applications.

:Price

Due to its lower polarity compared to DOP, DOTP exhibits lesser migration and is more hygienic, which increases its price. Also, as its consumption dose is higher than that of DOP, it might increase production costs. However, in scenarios emphasizing hygienic applications, DOTP could be considered.

2.Epoxidized Soybean Oil

:Usage dose

Epoxidized soybean oil, also known as ESBO, exhibits a substitution ratio (SF) of 1.10 compared to DOP. Therefore, to substitute it, it requires roughly a 10% higher usage dose than DOP.

:Health considerations

Epoxidized soybean oil is preferred over DOP in terms of health since it has a higher molecular weight, resulting in lesser migration. It’s derived from soybeans, based on a plant origin.

Price:

Epoxidized soybean oil often requires a higher consumption than DOP. However, in situations where the price of DOP has escalated and health issues are a priority, ESBO becomes more economical and cost-effective.

3.DOA

:Usage dose

DOA demonstrates an SF or substitution ratio of 0.93, meaning that to achieve a similar effect to DOP, a lower dose of DOA is required. Its consumption amount is almost 0.07% less than that of DOP.

:Health considerations

DOA, due to its adipate structure, has a lower tendency to migrate compared to DOP and is often chosen as a substitute, particularly in hygienic applications and environments with lower temperatures (10 degrees Celsius or lower).

:Price

DOA, due to its unique properties, is suitable for products that require performance at lower temperatures. Additionally, this chemical compound from the adipate family is more expensive compared to DOP, which belongs to the phthalate family.

4.EPOXY FATTY ACID METHYL ESTER (EFAME)

:Usage dose

Generally, EFAME has a greater softening effect compared to DOP. More precisely, its substitution ratio (SF) is 0.9, which is approximately 10% less than the amount of DOP. This means that achieving a similar softening effect to DOP requires a lower usage of EFAME.

:Health considerations

EFAME is recognized as a phthalate-free and environmentally friendly alternative to DOP due to its lower migration, reduced health concerns, and its biodegradability. These qualities make it particularly significant for hygienic applications.

:Price

Compared to DOP, EFAME, as a plasticizer, has differences such as reduced migration, lower usage doses, enhanced health aspects, and a more suitable price. However, the only potential difference with EFAME compared to DOP might be its tendency towards a slightly yellowish color. This aspect makes EFAME an excellent choice for applications where the color of the plasticizer is not a critical concern.