Cyclopentadiene oligomers

Cyclopentadiene oligomers up to octamers can be effectively analy2ed and quantified by supercritical fluid chromatography using a chemically bonded methyl siUcone capillary column. 

Cyclopentadiene oligomers have been formed by vapor deposition of CPD on kaolin to afford a sorbant for removal of oil from water (71). They are also employed as coatings for controlling release rates of fertilizers (72). Thermal addition of sulfur to a mixture of DCPD and CPD oligomers has led to a number of beneficial appHcations such as waste water oil adsorbant powdery foams (73), plasticized backing for carpets and artificial turfs (74), and in modified sulfur cements for encapsulating low-level radioactive wastes (75). 

Norbornenyl functionalised linseed oil and cyclopentadiene oligomer-based thermosetting resins have been successfully synthesised using dicy-clopentadiene or other polycyclic norbornene-based comonomers as cross-linkers. New biorenewable-based thermosets have been successfully synthesised by the ring opening metathesis polymerisation of norbornenyl functionalised fatty alcohols of soybean and castor oils. The castor oil-based thermoset exhibits lower soluble fractions and higher thermal stability and mechanical properties compared with the soybean oil-based thermoset. This is due to more effective cross-linking. ... 

Ring opening polymerised norbomenyl functionalised linseed oil and cyclopentadiene oligomer produces a soft and flexible rubber with a Tg of -29°C. The yellow transparent thermosets which vary between soft and flexible to hard and strong, are obtained by an increase in dityclopentadiene... 

Table 3. Yield (wt%) of Cyclopentadiene Oligomers at Various Temperatures and Contact Times...

Cyclopentadiene oligomers have been formed by vapor deposition of CPD on kaolin to afford a sorbent for removal of oil from water (70). They are also employed as coatings for controlling release rates of fertilizers (71). Thermal addition... 

GLYCOLS - ETHYLENE GLYCOLAND OLIGOTffiRS] C/ol 12) Oligomers of cyclopentadiene... 

Sulfur Polymer Cement. SPC has been proven effective in reducing leach rates of reactive heavy metals to the extent that some wastes can be managed solely as low level waste (LLW). When SPC is combined with mercury and lead oxides (both toxic metals), it interacts chemically to form mercury sulfide, HgS, and lead sulfide, PbS, both of which are insoluble in water. A dried sulfur residue from petroleum refining that contained 600-ppm vanadium (a carcinogen) was chemically modified using dicyclopentadiene and oligomer of cyclopentadiene and used to make SC (58). This material was examined by the California Department of Health Services (Cal EPA) and the leachable level of vanadium had been reduced to 8.3 ppm, well below the soluble threshold limit concentration of 24 ppm (59). 

In order to have a successful polymerization of such a diene-dieno-philic monomer, both the diene and dienophile portions must be highly reactive. In the examples of the fos-cyclopentadienyl monomers given, this high reactivity is also the basis of most of the troubles associated with the polymerization reaction in that the monomers cannot be suitably purified. Purification in this case involves the separation of a mixture of monomer and other oligomers as well as adducts of monomer and monoalkylated cyclopentadiene. Ideally, a diene-dienophilic monomer which could be held in an inactive state during purification and until ready for the polymerization reaction would represent the perfect monomer for such a polymerization. 

Infrared spectroscopy of (x 4-cyclopentadiene)Fe(CO)3 moiety-attached ferrocene and its oligomers, 2, gave information on the electronic structure of the mixed-valence complexes 19 the v(CO) bands of the Fe(CO)3 moiety20,21 could sense the oxidation state of the nearest terminal ferrocenyl group. 

Although a portion of the higher molecular weight polymer is a result of vinyl addition polymerization, the oligomers are formed through successive additions of cyclopentadiene through a Diels-Alder reaction... 

The term hydrocarbon resins refers to hydrocarbon oligomers derived from coke-oven gas, coal-tar fractions, cracked and deeply cracked petroleum stocks, essentially pure hydrocarbon feeds, and turpentines. Typical hydrocarbon resins (HRs) include coumarone—indene resins (ClRs), petroleum resins (PRs), styrene polymers (SPs), cyclopentadiene resins (CPRs), and terpene resins (TRs). 

The term CPR refers to cyclopentadiene low molecular weight homopolymers and copolymers derived from coat tar fractions or from cracked petroleum streams. These resins are produced by holding a cyclopentadiene-containing stock at elevated temperature for an extended period of time. The temperature at which it is held determines whether the dimer, trimer, or higher oligomers are obtained. 

The interest in homopolymeric AHRs is growing, since the use of pure monomers allows one to achieve some colorless products with certain higher-performance qualities (increased softening temperature, reactivity, etc.). Styrene homooligomers can be obtained from pure styrene or from styrene concentrates by cationic oligomerization. Styrene co-oligomers can be obtained from styrene and a-methylstyrene, vinyltoluene, cyclopentadiene, or vinylic ethers by cationic oligomerization [113,117—120]. 

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