From left-to-right, Steven Bischof, PhD, Team Leader; Jeff Gee, PhD, Research Fellow; Brooke Small, PhD, Research Fellow; Carl Stouffer, NAO Research Engineering Fellow
Our team of experts answer the most frequently asked questions. Please don’t hesitate to reach out to us if you have any questions!
Yes. Chevron Phillips Chemical Company’s alpha olefin plant, which started up in August 2000, produces a C26-28 alpha olefin wax having about 85% linear 1-alkene.
This product is an example of an alpha olefin wax distilled sharply into two such heavy carbon chains. Furthermore, technological innovations increase the alpha content by nearly 50% over that of the previous NAO C24-28 wax fraction that was marketed for many years.
Alpha Olefin C26-28 should also satisfy your need for a tighter-range, heavy, highly linear NAO wax. If you need an even heavier NAO, we produce C30+ with an alpha content greater than 80%. We expect both products to be valuable feedstocks for olefin chemistries performed on high molecular weight NAOs.
Great question! There are a number of ways to convert normal alpha olefins (NAOs) to internal olefins. Several of these methods are shown in the scheme below. By carefully choosing the reaction conditions and the catalyst, a diverse range of products with widely varying physical and chemical properties can be made. One can tailor the branching, molecular weight, degree of substitution on the olefin, and sometimes even the location of the double bond to match the need.
While much of the alpha olefin sulfonate produced today is made from blends of 1-tetradecene and 1-hexadecene, alpha olefins having other alkyl chain lengths will react rapidly with SO3.
In fact, Chevron Phillips Chemical has worked with a leading producer of sulfonation equipment to demonstrate the commercial viability of producing AOS from a blend of alpha olefins having chain lengths from C12 all the way up to C24. This olefin blend sulfonated as easily as the traditional C14/16 NAO blend, and free samples of the dried sodium salt are available upon request. The carbon number distribution of this new blend is given below.
As a matter of fact, the acid catalyzed addition of carboxylic acids to alpha olefins produces esters with interesting properties. Essentially all the esters formed are secondary esters, in contrast to the primary esters derived from natural products.
The olefin-derived esters have excellent pour points and outstanding hydrolytic stability. The wide range of olefin chain lengths available from Chevron Phillips Chemical provides an array of choices for ester molecular weight, so that many relatively low-viscosity esters are possible. Carboxylic acid chain length is another variable in ester design. The C14 propionate cited below is now commercially available from Chevron Phillips Chemical.
The addition of maleic anhydride to a normal alpha olefin generates an alkenyl succinic anhydride (ASA) that can be an entry point to several polar derivatives. Some ASAs are available commercially; alternatively, the addition is easily performed in a batch reactor and the ASA is separated from unreacted olefin by distillation. No solvent or catalyst is necessary, and the technology can be practiced with our entire range of normal alpha olefins from 1-butene to C30+ normal alpha olefin wax.
The typical reactions of organic acid anhydrides with water, alcohols, amines and metal hydroxides can be used to generate numerous derivatives such as alkenyl succinic acids, half-esters, diesters, succinamic acids, succinamides, succinimides and ASA salts, some of which are shown below.
Polyfunctional reagents such as polyamines and polyhydridic alcohols can be used to generate polyamides and polyesters. Many of these derivatives have surface active properties and can be used as emulsifiers, thickeners, dispersants, surface modifiers for leather, textiles, and paper, and corrosion inhibitors.
Reaction of normal alpha olefins with hydrogen cyanide, in an acidic medium, can produce either N-secondary amides or amines, depending upon reaction conditions. A particularly useful acidic catalyst, shown below, is the water/sulfuric acid/boron trifluoride system.
You can isolate the intermediate N-secondary formamide or hydrolyze the formamide to the N-secondary amine. This catalyst system has given yields of more than 90%. The catalyst can even be deposited on alumina or alumina silicate, and still produce yields in excess of 90%. Use of alkylnitriles will produce amides other than the formamide. Alternatively, reaction of hydrogen cyanide with 2-alkyl-1-alkenes produces N-tertiary formamides or amines, while use of alkylnitriles with 2-alkyl-1-alkenes will produce other N-tertiary amides.
Normal alpha olefins’ shelf life can be indefinite if they are stored under inert atmosphere in the absence of water and oxygen. Water is not entirely insoluble to normal alpha olefins, and water can be a poison to many catalytic processes involving normal alpha olefins, including cationic olefins polymerization. Oxygen can react with normal alpha olefins to form peroxides in ppm concentrations. Peroxides are also poisons to many polymerization catalysts. Peroxide formation during storage occurs as follows:
Peroxides also react to form carbonyls and alcohols. Carbonyls and alcohols can reduce your catalysts’ activity too.
We can advise you on how to analyze for peroxide/carbonyl content and removal. Finally, note that many chemists commonly store their reagents over drying agents. Drying agents can isomerize normal alpha olefins to form internal olefins, which are less reactive than normal alpha olefins in polymerization experiments.
There are three technologies practiced on a commercial basis:
An alternative method employs alkenyl sulfonic acid neutralization and hydrolysis in a sodium hydroxide/isopropyl alcohol slurry.
A simple laboratory procedure utilizing tetradecene/hexadecene alkenyl sulfonic acid, 2:1 ratio (by wt.), combines the following constituents:
Alkenyl sulfonic acid hydrolysis in refluxing alkaline isopropyl alcohol for six to eight hours eliminates the delta-sultone. Insoluble in isopropanol, the AOS salts are easily isolated and dried. Increased pressure and higher hydrolysis temperatures would greatly reduce hydrolysis time.
The AOS product is a white to light yellow powder that readily dissolves in water, even at room temperature. The powder is suitable for laundry applications and permits formulation to a wide range of activities for many applications. The procedure is also applicable to potassium, calcium and magnesium salts.
Absolutely! With its recently disclosed proprietary technology (U.S. Patent 6,291,733) for linear dimerization, Chevron Phillips Chemical can dimerize a wide range of alpha olefins to form linear internal olefin products. Below is a typical reaction.
Using our technology, it is possible to make dimers that are over 75% linear and as little as 20% methyl-branched. This high linearity represents a dramatic improvement over currently available commercial dimer products. The catalysts are capable of dimerizing any high-purity alpha olefin, such as any of Chevron Phillips Chemical’s C4- C30+Normal Alpha Olefins.
The direct addition of silanes to alpha olefins is also known as hydrosilation of alpha olefins. It is catalyzed by peroxides, ultraviolet light or transition metal compounds. In most commercial processes, a silane such as Cl3SiH reacts with an alpha olefin in the presence of a catalyst (chloroplatinic acid, H2PtCl6, molar concentration = 1x10-8) to make an alkylchlorosilane.
Other metals can catalyze this reaction, but chloroplatinic acid (CPA) is the preferred catalyst because of its high activity and low catalyst concentrations.
Alpha >> vinylidene > trisubstituted = internal olefins
The most common side reaction is the isomerization of alpha olefins to internal olefins. Low reaction temperatures (60–80°C) reduce isomerization.
The alkyltrichlorosilane is frequently reacted with an alcohol to make an alkyltrialkoxysilane:
Methanol, ethanol and t-butanol are the preferred alcohols since they can be readily removed when coating a surface:
Absolutely! Some ASAs are made by heating an alpha olefin with maleic anhydride. For other ASAs, the alpha olefin is first isomerized to a mixture of linear internal olefins, which is then combined with maleic anhydride to make a mixture of ASAs having a lower pour point than an ASA made directly from an alpha olefin.
For any ASA, a number of additional chemistries are possible. Reaction with alcohols is a common next step, giving either diesters or half-esters/half-acids. Because they have highly branched structures, the diesters make good pour point depressants.
Amines will also react with ASAs, giving an amide/acid type product.
Similarly, water will open the anhydride to a diacid, which can be used in polyesters or neutralized with base to give a disalt.
To learn about other exciting possibilities with alpha olefins, please give us a call.
Chevron Phillips Chemical’s traditional NAO 24-28 and 30+ products contain significant quantities, 30 to 45 wt.%, of vinylidenes (2-alkyl-1-alkenes) and internal olefins. In some practiced chemistries, the vinylidenes and internal olefins are either unreactive or reduce the product selectivity.
To support these chemistries, we have introduced two new products: NAO 26-28 and NAO 30+ HA (for NAO 30+ High Alpha). These products have alpha olefin contents greater than 80 wt.% and will provide increased reactivity and improved product selectivity in some chemistries practiced on the NAO 24-28 and 30+ fractions. Four chemistries that should benefit from the increased alpha olefin content of the new NAO 26-28 and NAO 30+ HA products include hydrosilylation, epoxidation, aromatic alkylation and the Koch reaction.
