Pinenes dipentene and

Terpene Copolymers. Terpenes are routinely polymerized with other terpenes or with nonterpene-type monomers (97—102). The AlCl catalyzed polymerization of P-pinene, dipentene, and terpene oligomers (oily dimers and trimers) has been found to yield resins with softening points ranging from 0—40°C (103). 

Fig. 1 shows the selectivities of the main isomerization products a-pinene, dipentene and camphene during the HDS experiment with carbon I and III. Similar results were obtained with other carbon samples. In fig. 1 these results are compared with the isomerization behaviour of AI2O3 (Rh6ne-Poulenc SCS 79 delta-alumina) and SiC>2 (Rhone-Poulenc DBM 250 silica), which were studied previously [Ref.3,4], Carbon induces profound changes in the spectrum of isomerization products dipentene is the major... 

The leaf oil is practically a terpene oil, the principal constituents being pinene, dipentene, and laevo-limonene. Bornyl and geranyl esters are present in very small amount. Two samples gave the following values —... 

The characteristic odour of the oil is due to the presence of thymol. In addition, cymene, a-pinene, dipentene, and -y-terpinene are present. The oil itself is used to a certain extent in India for medicinal purposes, but its principal use is for the preparation of thymol. According to Stohmann, carvacrol is also present, but this statement requires con> firmation. 

The polymerization of p-pinene by irradiation with °Co y-rays in vacuo gives a polymeric material that partially precipitates from the liquid monomer. However, polymerization is accompanied by concurrent isomerization of p-pinene to dipentene and other isomers. There is evidence for the participation of ions in the mechanism [94]. y-lrradiation of a-pinene at 30°C, on the other hand, results in formation of hydrogen, isomers of a-pinene (dipentene and ocimene), and about 5% of polymeric material [95]. 

A process of polymerization of isomerized a-pinene or turpentine with vinylbenzenes has been disclosed (105). a-Pinene or turpentine is isomerized by flash pyrolysis at 518 5° C in a hot tube reactor to yield a mixture of predominantly dipentene and i7t-alloocimene... 

The principal constitaenta of liussian turpentine are, according to Sohindeltaeiser, fl-pinene, sylvestrene, and dipentene. A little deifro-ti-... 

Terpene resins are most commonly used in adhesive production, where they confer very strong tackifying properties. The terpene resins improve the resistance of adhesives to oxidative degradation. These resins are normally produced from p-pinene and are light yellow in colour. Polymers of dipentene and limonene are also available as resins. 

Turpentine is a mixture of CioHie volatile terpenes (hydrocarbons made of isoprene units). There are actually four different types and methods of making turpentine, including steam distillation of wood. The two pinenes, a and P, are major components of turpentine. Other compounds found in abundant amounts are camphene, dipentene, terpinolene, and A -carene. Although it has been replaced by petroleum hydrocarbons as paint thinners (lower price, less odor), turpentine is still a good solvent and thinner in many specialty applications. The use pattern for turpentine is as follows synthetic... 

The terpenes used were mainly /3-pinene fractions provided by DRT (Soci6td des Derives Rdsiniques et Terpeniques, Vielle-S Girons) and, for certain experiments a turpentine oil containing the main three terpenes a-pinene, /3-pinene, and A -carene. The /3-pinene fractions contained 80-90% /3-pinene, 2% a-pinene, 4-5% myrcene, 2-3% dipentene and 700-1500 ppm S. GC-MS analyses showed that sulfur impurities were composed of alkyl and alkenyl sulfides (mainly dimethyl sulfide), alkyl and alkenyl disulfides (mainly dimethyl disulfide), trisulfides, thiophene and alkylthiophenes (methyl, dimethyl, acetyl and tertiobutyl). 

Detailed study of the coriander spice oil composition showed that the d-linalool content ranged from 60 to 70% and the hydrocarbon content was about 20%. a- and (3-pinenes, dipentene (limonene), p-cymene, a- and y-terpinenes, n-decanal, geraniol and 1-borneol were also identified as constituents of the spice oil. 

PROP Consists mainly of eugenol and chavicol (55-65%), major portion of balance consists of terpenes (a-pinene, myrcene, and dipentene), small quantities of citrol, nerol, cineol, and other terpenoids have also been found (FCTXAV 11,855,73). YeUow or brown liquid aromatic odor, pungent, spicy taste. Sol in ale and glacial acetic acid. 

PROP Contains 3-8% volatile oil (pinene, dipentene, etc.), 60% resins, 20% gum (polysaccharide fraction), and 6-8% bassorin (FCTXAV 16,637,78). A gum from the trees Boswellia carterii Birdw. and other Boswellia species (Fam. Burseraceae). 

The most widespread use of limonene has been as a raw material for the manufacture of adhesives, such as the glue on labels and envelopes. Terpene monomers used for resin production are pinene, dipentene from turpentine and rf-limonene. Waterless hand cleaners produced from d-limonene were among the first to replace solvents such as mineral spirits. Although ri-limoncnc is more expensive than mineral spirits and kerosene, the former is used because of the pleasant citrus aroma and its claimed biodegradability (Coleman, 1975 Kutty et al., 1994). Many flavor chemicals... 

Complex volatile hquids derived from flowers, stems, and leaves, and often the entire plant. They contain terpenes (pinene, dipentene, etc.) and are used chiefly for perfumery and flavorings. Usually resinous products are admixed with them. Turpentine is a highly resinous essential oil. 

The quantitative conversion of dipentene and 3-pinene to form polymers stirred interest in (1) the pyrolysis of a-pinene to dipentene and allo-ocimene (34) and (2) the synthesis of B-pinene from a-pinene (35). However, due to the availability of citrus limonene as a supplemental source for dipentene, the pyrolysis scheme is no longer economically attractive. 

The acid catalysed isomerization of a-pinene proceeds via two types of reactions, one giving bi- and tricyclic products such as camphene, p-pinene, tricyclene, and bornylene and the other giving rise to monocyclic compounds such as dipentene, terpinolene, a-terpinene, y-terpinene and p-cymene [1]. Over solid catalysts such as clays, mineral oxides and inorganic salts,the main product is camphene [2], of particular interest as an intermediate in the synthesis of camphor. Camphor is of value due to its aroma and pharmaceutical properties. 

Terpenes once commonly used are turpentine, dipentene and pine oil (p. 38). Turpentine varies with grade, but is principally a-pinene dipentene is mainly limonene while pine oils are mixtures, chiefly of terpene alcohols. Turpentine was once the main solvent for house paints, but has now been completely replaced by white spirit. Dipentene can be used as an anti-skinning agent (Chapter 10). 

These resins are generally grouped into three main categories depending on the source of the raw material (1,203,204). The indene-coumarone resins are coal tar based. Aliphatic, aromatic, and dicyclopentadiene resins are made from distillate fractions of cracked petroleum. Polyterpene resins are produced using monomers isolated from turpentine oil (a- or jS-pinene) or etheral oils of lemon, orange, mandarin, or caraway (d,Z-limonene or dipentene and d-limonene). 

The term TR refers to low molecular weight polymers of terpenes, which are hydrocarbons of the general formula CioHig, occurring in most essential oils and oleoresins of plants, and phenol-modified terpene resins. Suitable terpenes include a-pinene, P-pinene, dipentene, limonene, myrcene, bomylene, camphene, and the like. These products occurs as by-products of coking operations of petroleum refining and paper manufacture. 

Dextro-pinene, dextro-limonene, dipentene ( ), and a hydrocarbon which is probably menthene were identified in the leaf oil. A sesquiterpene, probably c nene, and traces of esters are present. The oil has the following characters —... 

The oil contains 1-a-pinene, dipentene, sylvesttene, and a small amount of hornyl acetate. 

The oil distilled from the bark of the root, according to Pilgrim, has a specific gravity 0 994 and optical rotation + 50 . It contains pinene, dipentene, phellandrene, cineol, camphor, eugenol, safrol, bomeol, and oaryophyllene. 

Simonsen and Ghose report on experiments carried ont on the distillation of camphor and camphor oil from the leaves of young trees grown in various parts of India. They obtained from 0 25 to 2 01 per cent, of camphor, and a varying amount of camphor leaf oil. This oil, after separation of the camphor, contained d-alp -pinene, dipentene, cineol, terpineol, caryophyllene, and a trace of cadinene, but no safrol. 

According to Schimmel Co. this oil contains ji-cymene, cineol, and ascaridol, C qHj,02. Traces of terpenes and phenols are also present. Tardy has reported on an oil under this name which had a specific gravity 0-876, and optical rotation - 6° 30. It contained a-pinene, dipentene, terpineol, cumic aldehyde, eugenol, sesquitei-penes, and acetic esters. 

These chemists identified the following bodies in the oil a-pinene, cineol, thujone, camphor, and inactive terpenes, probably consisting of a mixture of dipentene and terpinene. 

Pinene, cymene, dipentene, and bornyl acetate are also present in the oil. 

Canadian golden oil is obtained from Solidago canadensis. It is a yellow oil of aromatic odour, of specific gravity 0 859 and optical rotation - 11 10. It consists of about 85 per cent, of terpenes, of which pinene, phellandrene, dipentene, and probably limonene are the constituents. There are also present bomeol, bornyl acetate, and cadinene. 

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