| 释义 |
microcrystalline, a. Geol. and Min.|maɪkrəʊˈkrɪstəlaɪn|
[f. micro- + crystalline.]
Formed of microscopic crystals. microcrystalline wax, a mixture of hydrocarbons of higher molecular weight than those in paraffin waxes and with a melting point of up to 90°C which is obtained from the residual lubricating fraction of crude oil and is used in making waxed paper, adhesives, and polishes.
1876A. H. Green Phys. Geol. 46 The aid of a pocket lens becomes necessary..to recognise their crystals, and these [rocks] are known as Micro-crystalline. 1879Rutley Stud. Rocks xi. 188 The central portion consists of vitreous, and at times, micro-crystalline matter. 1891Athenæum 24 Jan. 126/1 A heavy, yellow, microcrystalline powder. 1943Jrnl. Amer. Pharmaceutical Assoc. (Sci. Ed.) XXXII. 111/2 A series of ‘Petro-waxes’, one of which melts at about 160°F. It is a white microcrystalline wax that is available in quantity. It was thought that due to the microcrystalline structure of this wax, it might make stable ointments containing as much as 50% water. 1944H. Bennett Commercial Waxes i. 60 The designations of microcrystalline and amorphous waxes are now being used synonymously although the former is a more accurate designation. 1957Van der Have & Verver Petroleum xi. 339 As its name implies, ‘micro-crystalline wax’ has a very fine crystal structure; it is a flexible and often somewhat sticky product; it has a high molecular weight (550–600) and a melting point within the same range as ceresin. 1972Oxf. Univ. Gaz. CII. Suppl. No. 3. 10 They [sc. metal objects] are boiled to remove chlorides and after drying in an infra-red cupboard are impregnated with microcrystalline wax.
Hence ˌmicrocrystaˈllinity, the property or state of being microcrystalline.
1946Nature 28 Dec. 930/1 Microcrystallinity and a capacity to yield strong and pliable fibres are properties by no means confined to the linear poly-amides. 1967Encycl. Polymer Sci. & Technol. VII. 207 It is possible to distinguish microcrystallinity, detectable by x-ray examination from macrocrystallinity, visible through a polarizing microscope. |