Jun 13, · Phthalate Plasticizer. phthalate plasticizers used together with stannous catalyst and silyl-group containing compounds reduce shelf-life of one-component products From: Handbook of Plasticizers (Second Edition), Related terms: Energy Engineering; Monomers; Phthalates; Resin; Stabilizers; Volatile Organic Compound; Dibutyl Phthalate; Plasticizer. Phthalates (pronounced THAL-ates \?tha-?lats\) – covering ortho-phthalates – are the most commonly used plasticisers (US: plasticizers) in the world. In Europe, about one million tonnes of ortho-phthalates and terephthalates are produced each year – about 80% of the entire plasticisers market – of which approximately 95% are used to make flexible polyvinyl chloride (PVC).
Phthalates are a group of chemicals used to make plastics more durable. They are often called plasticizers. Some phthalates are used to help dissolve other materials. Phthalates are in hundreds of products, such as vinyl flooring, lubricating oils, and personal-care products soaps, shampoos, hair sprays. How to be an effective and successful teacher phthalates are in polyvinyl chloride plastics, which are used to make products such as plastic packaging, garden hoses, and medical tubing.
People are exposed to phthalates by eating and drinking foods that have contacted products containing phthalates. Some exposure can occur from breathing phthalate particles in the air. Children crawl around and touch many things, then put their hands in their mouths. Because of that hand-to-mouth behavior, phthalate particles in dust might be a greater risk for children than for adults. Some types of phthalates have affected the reproductive system in animals. Human health effects from exposure to low phthwlate of phthalates are not as clear.
More how to partition an external hard drive vista is needed to assess the human health effects of exposure to phthalates. Finding a detectable amount of phthalate metabolites in urine does not mean the levels will cause harmful health effects.
Biomonitoring studies measure levels of chemicals, such as phthalate metabolites, that people have in their bodies. Levels that are not likely to cause harm are called reference values.
Physicians and public pphthalate officials use reference values to decide if people have been exposed to higher levels of these chemicals than are found in the general population. Biomonitoring data can help scientists plan and conduct research on exposure and health effects. Skip directly to site content Skip directly to page options Skip directly to A-Z link.
National Biomonitoring Program. Section Navigation. Facebook Twitter LinkedIn Syndicate. Phthalates Factsheet. Minus Related Pages. How People Are Exposed to Phthalates People are exposed to phthalates by eating and drinking foods that have contacted products pbthalate phthalates. Levels of Phthalate Metabolites in the U. CDC researchers found measurable levels of many phthalate metabolites in the general population. This finding indicates that phthalate exposure is widespread in the U.
Adult women have higher levels of waht measured in urine than do men for those phthalates that are used in soaps, body washes, shampoos, cosmetics, and similar personal care products. Non-Hispanic Blacks have higher levels of exposure for several phthalates and phthalate alternative metabolites than do Non-Hispanic Whites. Top of Page. Links with this what is a phthalate plasticizer indicate that you are leaving the CDC website.
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Phthalate plasticizers are the most commonly used plasticizers in PVC. The PVC polymer chains are attracted to one another, and therefore from a very rigid structure. The phthalate plasticizers are added to PVC to help the chains slide against each other, therefore, softening the PVC. The structure of phthalate plasticizers is that of a phthalate ester, which is simply a phthalate with, an ester group (see structure . Phthalates are a family of chemical compounds primarily used to make polyvinyl chloride (PVC), or vinyl, flexible and pliant. Phthalates are one of the most commonly used plasticizers in the world and are categorized as “high” or “low,” depending on molecular weight.
April 6, Brian Amato. Sarah Karl. Carla Ng. Plasticizers: An Introduction.. Early Plasticizers. Theory: Mechanism of Plasticizer Effect on the Polymer..
Phthalate Plasticizers. The Phthalate Plasticizer Market.. Health or Hype? In more technical terms, the addition of a plasticizer generally causes a reduction in the cohesive intermolecular forces along the polymer chains. The chains can then move more freely relative to one another, and the stiffness of the polymer is reduced. Plasticizers are usually inert organic materials with high boiling points and low vapor pressures.
Esters are commonly used due to their favorable physical interactions with high-molecular-weight polymers. Two classes of plasticizer exist: primary and secondary. Secondary plasticizers, on the other hand, act not on the polymer but the primary plasticizer, increasing its effectiveness There are two primary means of plasticization: internal and external.
Internal plasticization involves the chemical alteration of a polymer or its monomer prior to polymerization. This can be done either by random copolymerization or side chain grafting. The former tends to increase the flexibility aided by the random quality; a more ordered copolymerization would imbue a higher degree of crystallinity thereby giving the opposite effect.
The latter lowers the glass transition temperature, T g , and reduces crystallinity by disrupting physical interactions between the chains. The second type of plasticization is external. It is what we normally think of when we talk about a plasticized polymer, and involves the addition of an organic chemical see above during compounding after polymerization.
This chemical interacts with the polymer only physically, via its solvent capabilities. This type of plasticization is usually done at elevated temperatures. External ester plasticizers are the most commonly used in the industry.
They carry the advantage of great flexibility: since they are added after polymerization plastics of varying degrees of flexibility may be produced from one polymer formulation. There are several theories that seek to explain how a plasticizer affects a polymer in both internal and external plasticization.
Three major theories are described below, as well as some important additions to the theory When the polymer is heated in order to be plasticized, the binding is weakened and the smaller plasticizer molecules are able to slip in between the chains. It has been shown that the free volume of a polymer greatly increases when it reaches the glass transition temperature.
By this logic, then, the study of plasticization is essentially the study of methods for lowering the glass transition temperature. We know that the glass transition temperature is the point at which significant, one might say concerted, molecular motion begins to occur.
This motion, which corresponds to an increase in the free volume of the polymer which is what we want , can be due to motion of the chain itself, of its ends, or of side chains attached to it. So how does the addition of the plasticizer facilitate this? Its lower molecular weight means an increase in the free volume per volume of material you are not adding a lot of volume with these small molecules, but there is a lot more free space between them than between the polymer molecules.
If you are using a small polymer molecule as a plasticizer, it has a lower glass transition temperature than the resin you are adding it to, so the T g of the resulting mixture will be lower.
So the addition of a plasticizer in essence allows a polymer to behave, at room temperature, in a way the pure resin would only behave at elevated temperatures. The specific type of plasticizer that is of concern to this report is the phthalate plasticizer. Phthalate plasticizers are the most commonly used plasticizers in PVC. The PVC polymer chains are attracted to one another, and therefore from a very rigid structure.
The phthalate plasticizers are added to PVC to help the chains slide against each other, therefore, softening the PVC. The structure of phthalate plasticizers is that of a phthalate ester, which is simply a phthalate with, an ester group see structure below figure 1 1.
Phthalate plasticizers are colorless liquids like vegetable oil with a faint odor, and they are insoluble in water. They are however, miscible in mineral oil, hexane, and most organic solvents. This makes them readily soluble in bodily fluids, such as plasma and saliva 1. DEHP has been the most commonly used, and is still the plasticizer of choice for all PVC medical and surgical products.
The structures of both are shown below in figures 2 and 3 respectively 1. Figure 2. Figure 3. They command the market due to their low cost and easy availability. Other common plasticizers include specialty phthalate esters, adipates, and trimellitates which are used for low-temperature applications.
This polymer is found in anything from food packaging to construction materials to toys to medical devices. Without the existence of plasticizers, it would have very little commercial use.
It is a symbiotic relationship, however: few polymers interact as favorably with plasticizers as PVC. Not only is it capable of taking in high concentrations of plasticizer, it also retains them much better than most polymers. This is partly due to the very heterogeneous morphology of PVC. It contains regions that are highly amorphous, semi-crystalline, and highly crystalline.
In choosing an appropriate plasticizer, several considerations are important. One must take into account what the application of the polymer will be: will it be high-temperature or low-temperature? What degree of flexibility is needed? The size of the plasticizer molecule, and more importantly its bulk taking into account the presence of branches or side chains will affect both the efficiency and the temperature behavior of the polymer.
Efficiency in this case is basically a measure of how much plasticizer must be added to achieve a give amount of softness in the polymer. The larger the molecule more carbon atoms , the lower the efficiency. More highly branched molecules also make for less efficient plasticizer. However, increasing the size of the molecule increases its mass, and therefore lowers volatility. This is desirable if your polymer is to be used in high-temperature applications, where more volatile molecules would evaporate out.
On the other hand, if your polymer is to be used in low-temperature applications, such as flexible tarps for use outdoors, highly linear plasticizer molecules are desirable. For most common household applications that use PVC, the polymer is not being subjected to any temperature extremes, aside from the somewhat high temperate of the water which hits your plasticized PVC shower curtain every day.
Figures 4 a and b , below, show two common applications of plasticized PVC. Figure 4: a rubber ducky and b blood bag, both made from plasticized poly vinyl chloride.
Figure 5 : PVC pipe, made without the use of plasticizers, is a stiff, strong material. Figure 6, below, shows some market data for the use of PVC 3. Figure 5: PVC use in the U. Phthalate plasticizers have been found to be a health concern when found in direct contact with bodily fluids.
Studies performed on laboratory animals have shown that there is direct evidence that certain phthalate plasticizers have a carcinogenic effect in vivo. Because they are readily miscible in organic solvents like plasma and saliva, humans have a chance of ingesting or absorbing them during common medical procedures. It is believed that once they are absorbed they are stored in the fatty tissue of humans, and therefore can be teratogenic.
Types of procedures where there is a risk of absorption or ingestion occurring are during blood transfusion, use of tubing for respiration, or in the use of catheters. Since the plasticizer is not covalently bound to the PVC molecule it can diffuse out into the plasma.
When DEHP is dissolved in plasma it is a result of the miscibility in albumin or lipoprotein. The choice of PVC for storing blood came about due to the increased survival rate of red blood cells when stored in PVC as compared to glass 2. It was concluded from this that an adult could get a dose from a bag of this type of nearly milligrams total or 5 milligrams per kilogram, and for a child it would be even higher 2.
Since these studies, which show that DEHP is potentially harmful, there have been more recent studies that show that it is actually beneficial to the production of cholesterol and phospholipid production during storage. From this study a dose response curve was made which shows that the greater the concentration of DEHP to which the red blood cells were exposed, the lower the hemolysis death of red blood cells during storage.
As to what exactly causes this phenomenon, there has never been a definitive answer. It may be that the plasticizer is some how interacting with the red blood cell cytoskeleton to neutralize any effects of oxidation or disconnection of the cytoskeleton, which would also lead to increased micro vascular formation 2.
From all of the research to date on this issue the consensus of the FDA is that further investigation needs to take place into the reproductive toxicity of DEHP. Also alternative plasticizers need to be investigated, and their toxicity needs to be evaluated in turn. A commonly asked question is, what are the consequences of using these chemicals? This is not a dilemma just for the plastics industry or Green Peace, but rather every person and creature on the earth whose lives are impacted by the use of plastics.
It is a truth that plastics have taken over many roles in the world we live in today, to a point where it is impossible to escape them. From the containers of the food we eat, the trash we produce, to the pacifier that we give to a child to teethe on. Plastics are unavoidable. What are the dangers of phthalates if there are any and how will they affect the overall environment? Currently there are limited studies that quantify the danger of phthalates to humans, but the effects demonstrated on some species are undeniable.
Research with laboratory rats has correlated DEHP with malformations in male rats by decreasing fetal testosterone levels. This indicates the possibility of transgenerational reproductive toxicity. Evidence similar to that above is prevalent, but how does it relate to humans?