Вообще об источниках африканского каучука стало европейцам известно в середине XVIII в., но большого интереса он не вызвал, так как и американский каучук было особенно непонятно как использовать. Местные же жители пользовались латексом лиан рода ландольфия с глубокой древности, для крепления перьев к стрелам и в качестве компонента яда для стрел.
Интерес к африканскому каучуку многократно усилился после каучукового бума в конце XIX в., когда огромные количества этого материала понадобились для шин колесного транспорта. Бельгийский король Леопольд II, получивший контроль над Конго в 1885 г. (“Congo “free” state”) в качестве парктически частной колонии, монополизировал добычу ресурсов, в первую очередь слоновой кости и каучука. Вооруженные отряды принуждали местное население собирать каучук в джунглях за минимальную плату или вовсе бесплатно, а не выполнивших норму по сдаче каучука подвергали казням и пыткам – в том числе насилуя и уродуя их жен и детей. Эта варварская практика прекратилась только в 1908 г., при этом, по некоторым оценкам, колониальными властями было убито до 10 млн людей.
https://upload.wikimedia.org/wikipedia/commons/8/80/Punch_congo_rubber_cartoon.jpg
Лиана Landolphia owariensis, которая была основным источником каучука, произрастает в тропической Африке от Гвинее до Судана и Танзании. В саваннах она может принимать вид куста или невысоких деревьев, но обычно растет вокруг других деревьев. Сборщики каучука, сделав надрез на лиане, обычно подставляли под него собственную руку, на которой густой латекс быстро сворачивался. Затвердевший каучук снимали с руки и собирали в комок, после чего переходили к следующему растению. В других местах каучук наматывали в виде нитей на палку, получая продолговатые куски типа сосисок. Если же латекс плохо сворачивался, его собирали в сосуды и перерабатывали в каучук нагреванием в горшках. В целом конголезский каучук обладал весьма хорошими свойствами и достаточно высоко ценился.

//One fact on which there is no disagreement is that the oldest rubber known was found in 1924, in Germany, fossilized in lignite deposits some 60 million years old. Apart from this, there seems to be only one other reference to natural rubber appearing in the “Old World” and this refers to the Ethiopians making play-balls and other rubber objects which then spread to ancient Egypt.
Heroditus attributed their origins to the Lydians.//

//WAS India rubber known to the ancients? Early writers do not mention it. We need not necessarily conclude, however, that the primitive peoples established on the shores of the Mediterranean were ignorant of the existence of this substance. The game of tennis is one of great antiquity, Herodotus attributing its invention to the Lydians. It is believed they got it from Egypt, which may have received it from Ethiopia. It is known that India-rubber trees are found in Abyssinia to-day. Hence it is reasonable to suppose they were indigenous there in earlier times, and that the inhabitants knew how to prepare resilient balls from their milky product. The Chinese have laid claim to the discovery of rubber, but have so far been unable to prove that they were the first to employ it. Modern Europe had no knowledge of it until the discovery of America. The Spaniards were much surprised to find the Indians playing tennis with balls made of a strange substance which excited their attention, as mentioned by Fernandez de Oviedo at the beginning of the sixteenth century.
…
Enormous supplies are stored up in Africa and her adjacent islands, where a variety of Ficus and great climbing shrubs, the Landolphia and Vahea, produce it. Stanley alludes to great numbers of these climbers entwining the trees, so as to make passage exceedingly troublesome. Attempts to force the price to unreasonable limits are therefore not likely to meet with permanent success, and we may banish fears of approaching exhaustion. The gum fully thrives, seemingly, nowhere but in the tropics. «It is the one jungle product which society finds indispensable,» said The Spectator recently, and, further: «Everybody knows that in the last five years the use of pneumatic tires for cycles and solid rubber tires for horse-vehicles has enormously increased our consumption of this article; but, quite apart from that more obvious fact, India rubber is daily being introduced more and more into all sorts of machinery. Highly competent judges say that if the output could be doubled within a year, so many applications would instantly arise that the price would not fall appreciably.» The negroes have no regard for the climbers, and cut them down in order to extract the utmost possible amount of sap.
…
Asia was the second country to furnish Europe with India rubber. The supply has of late years decreased in importance in consequence of the destruction of the trees. American varieties have been introduced with some success by the Indian Government. The principal native trees are the Urceola elastica, the Ficus elastica (the well-known window plant) and a species of fig, the Ficus religiosa, which is one of the most beautiful trees in the world. Its branches bend down, take root, and form new trunks. The great fig of Narbuddah has three hundred and fifty large and three thousand medium-sized stems, thus constituting in itself a veritable forest. The principal rubbers from India are the Assam and Rangoon. India rubber is also obtained in Oceania, notably in Sumatra, Java, and Borneo, but very little comes from Australia. It was formerly thought that the rubber tree only grew in moist ground, under tropical suns, but explorers have found them in hard soils on high plateaus.//

//The Lagos Silk Rubber, Funtumia elastica, formerly known as Kickxia Africana, is a handsome tree somewhat resembling a coffee plant when young. This rubber first came into notice in the colony of Lagos in 1894. The trees are tapped on a herring-bone system, and the latex collected in a vessel at the foot of the tree. In some districts the latex is coagulated by boiling; this method yields an inferior rubber owing to the damage often caused by excessive heating. A second method is to pour the latex into a tank excavated in the trunk of a fallen tree. The strained milk is added from day to day until the tank is full. It is then covered with palm leaves and left for 12 to 14 days or more, according to the season, until most of the watery portions have either evaporated or sunk into the wood.
The rubber obtained has a dark brown colour externally, with a paler section.
Funtumia is very susceptible to damage by intemperate tapping, and like other African rubbers, it has been largely exterminated in many districts owing to over-zealous collection. Recently plantations of this species have been established in several parts of West and Central Africa.

Although unsuitable for plantation purposes, the various climbing species of the genus Landolphia are still the chief source of wild African rubber. The Landolphias are widely distributed over the whole of tropical Africa, extending from 16 degrees North latitude to 23 degrees South latitude. They are found in almost all the forest regions of this area, and include at least ten species of valuable rubber-yielding plants. Among the most important are Landolphia owariensis, which occurs throughout West Africa and the Sudan, L. Heudelotii in West Africa, and L. Kirkii and L. Dawei in East Africa. Landolphia florida, which has also an extensive range, was known as a handsome and sweet-scented flowering plant long before its commercial value was recognised.
The rubber is exported in a great variety of forms, often as small balls or sausages. These are formed by winding up the strings of rubber which dry upon the plants, when the latter are gashed with a knife.

Ficus Vogelii is another rubber plant widely distributed in West Africa and the Sudan. There have been varying reports upon its produce, and it appears to deserve further attention.

In all the above-named species the source of the rubber is the stem. The so-called root rubbers of the Congo and Angola are derived from the Rhizomes of two semi-herbaceous plants Carpodinus lanceolatus and Clitandra henriquesiana. The creeping underground stems of these plants are about an inch in diameter. The natives extract the rubber by rasping and then boiling them in water.

In Madagascar rubber is obtained from other species of Landolphia, and from a tree, Mascarhenasia elastica, which is related to Funtumia, and resembles it in many respects.//

//Адриани для одного экземпляра Ficus elastica выс. 2,7 м нашел, что сок, взятый на самом верху, заключал около 17,7% твердого вещества; немного ниже — 20,98%, а на высоте 30 см от земли 25,1%.

Состав сока из верхушки был найден следующим:
Воды 82,30%
Каучука 9,57%
Смолы, раствор. в спирту и нераствор. в эфире 1,58%
Магнезиальных солей органических кислот 0,36%
Веществ, раствор. в воде, ближе не определенных 2,18%
Калийных и натриевых солей следы//

//В Ост-Индии для добывания каучукового сока, делают в коре круговые надрезы на расстоянии 25 см по всей длине ствола. Часть сока, в особенности из верхних надрезов, прямо сгущается на дереве; внизу же сок стекает в особые ямы и там сгущается или собирается в сосуды, сделанные из листьев Ficus’a. Чтобы получить из него К., сок выливают в кипящую воду и размешивают, пока К. не соберется в виде твердой массы, которую вынимают и сушат. Иногда же его выделяют прибавкой соли. Для ост-индского К. отличают сорта Ассам, Борнео, Сингапур, Рангун. Вообще говоря, добыча К. здесь ведется менее тщательно, чем в Америке, и он ниже по достоинству американского. Очень часто он содержит большое количество воды, кусочков коры, песку и пр. (до 50%); иногда сок во время процесса сгущения под действием солнечных лучей начинает бродить; масса получается клейкая, с противным запахом и пр. //

//THE FICUS ELASTICA occurs in suitable localities in the foot hills of ‘the Himalayas from Nepal east-ward; it has been found in the Khaia Hills up to an elevation of about 3000 feet and it reported from the Hukong and other valleys of Upper Burma up to nearly 5 ,000 feet abov sea level. In Assam the trees are found in the greatest number in th Darrang and Lakhimpur districts, but large quantities of rubber are imported into the Province from Bhutan, the Aka Duma and Naga Hills and from Burma.
It is found as a dominant tree in the evergreen forests of Assam; the finest specimens in hilly country up to an elevation of 2,500 feet.
It is not a gregarious tree, but in the Hukong Valley it reported a appearing scattered generally through the dense evergreen forests, occasionly a family group of four or five trees may bee met with, but these are very rare indeed and the usual thing is to come actos a mature tree at a distance, of every 200 to 300 yards in the richer forest//

//Formerly the overflow was collected from the ground after it was dry and was called «ground _ rubber,» but lately bamboo mats have been spread under the trees to catch this overflow. Ordinary bamboo mats 5′ X 2’
which cost from I anna to 1 t annas each, are used for collecting the overflow of latex from the cuts, These mats are first well dried in the sun for a week, for if green bamboo mats are used the rubber becomes discoloured and black, and for this reason for the last two years a strong solution prepared by boiling down 1 part of rubber bark (cut into small strips) in 60 parts of water for 5 hours, is smeared over each mat before use in order that the mat rubber might obtain the same red tint which the rubber derives from contact with the bark. As there has been little or no difference in the price of the coloured and uncoloured rubber, it is proposed to discontinue this practice and, instead, give every matman six well-dried mats, which he spreads out on the ground one by one, watching the drip of the latex from the cuts as they are being made.
The latex of the Ficus Elastica being very viscid only flows for about three minutes after the cut has been made: as soon as the drip from the cut ceases the mats are struck on the back with a stick to throw off strips of bark and other impurities which may have fallen from above and thus the same six mats may be used over and over again until they are thickly coated with coagulated latex. Any impurities seen imbedded in the latex are removed at once and the mats are then be put out in the sun, and when dry enough, (generally after two days), the rubber is pulled off and after picking and cleaning is weighed in at the godown and at once given out to women for further hand picking. At the close of each day’s work all the mats in use are put in the sun for a short time to dry and are then carefully put away under shelter from the dew and rain. Each mat will ultimately carry a sheet of rubber from three to five pounds in weight; but as soon as the mats turn black they should be thrown away.
Small tins and mats have been hung below the cuts to catch the latex, as an experiment, but the system has been abandoned as being too expensive.//

//The Assam rubber plant (Ficus elastica, Roxb.) is a large evergreen tree found in damp forests from the base of the Sikkimn Himalaya eastward to Assam and Arracan. Kurz remarks that it is frequent in upper Burma where whole forests exist in the valley of Hookhoom.
The Government of India has of late years attempted to establish regular plantations of rubber trees in Assamn and Madras. A memo- randum, by Mr. Gustav Mann, Conservator of Forests, Assam, describing the growth of trees from seeds, was given in the Kew Bulletin, 1891, pp. 100-2. In the Kew Bulletin, 1892, p. 68, it was stated that the imports into this country of Assam, and Rangoon rubber in 1891 amounted to 350 tons.//

//The amount of rubber obtained showed a singular irregularity year by year. It varied so greatly that while the yield in one year was as much as 26 pounds per tree, it would fall in another year to a little over two pounds. The value in money depended, of course, on the market, but at an average price of is. 6d. per pound the extreme yield per tree varied from 39s. to 3s.//

//Ficus elastica has been widely planted in Java in more recent years, but here again no better yields appear to be obtained. Berkhout estimated 17 lbs. of dry rubber per acre in the eighth year from planting, 26 lbs. in the tenth year, and 70 lbs. an acre in the twentieth year. Such yields render the trees almost useless for plantation purposes, and in many parts of the Dutch East Indies where they have been planted they are already being cut down to make way for Hevea.//

//India rubber plant, (Ficus elastica), large tree of the family Moraceae, once an important source of an inferior natural rubber. It was largely replaced as a source of rubber by the unrelated rubber tree (Hevea brasiliensis) in the early 20th century. The India rubber plant is native to Southeast Asia and is commonly grown as an indoor pot plant elsewhere. The young plants are durable and grow well under less-than-ideal indoor conditions.//

//https://i0.wp.com/borneoficus.info/wp-content/uploads/2019/06/Ficus-elastica-V02.jpg?resize=816%2C1147&ssl=1
ABOVE: A native of Assam in NE India tapping a Ficus elastica tree grown in one of the first commercial ” rubber plantations.” Note that the “tapper” makes multiple horizontal gouges in the bark and the liquid latex drips out naturally onto bamboo mats placed below the cuts. The natives of Assam were tapping the local Ficus elastica trees long before European plantation owners established large tea and rubber plantations in Assam in the 19th Century. Ficus elastica fig trees treated in this way could only be tapped for a year before needing a two year rest. Photo from Coventry (1906).//

свойства каучуков из различных растений
http://agrolib.ru/rastenievodstvo/item/f00/s00/e0000819/pic/000000.jpg

Источник заблуждения об «арубской резине», вероятно, состоит в ошибке перевода с английского
http://popadancev.net.s3-website-us-east-1.amazonaws.com/vulkanizaciya/comment-page-1/#comment-23332
Resin на английском это не резина, а смола в широком смысле этого слова. Aruba resin из выращиваемого на острове Алоэ вера действительно считалась лучшей в мире, но лишь в качестве слабительного средства.
//The aloe plant has been grown on Aruba since the mid-1800. The climate and the dry soil are particularly suitable for the aloe culture.  The plant flourishes well here: the Aruban aloe has an aloin content of 22 %, while the content of aloin in the rest of the world is 15% at the most.
The flourishing of the aloe culture in Aruba was under Commander Jan Helenus Ferguson (1866-1871). That’s why the road that leads from downtown through the aloe fields was named after him.  In the 19th century, an aloe plantation was also constructed in Socotoro; Socotoro has probably been named after the island of Sokotra or Socotora, at the time a British island in the Indian Ocean, off the coast of Yemen. That island lies on the same degree of longitude as Aruba and aloe is grown there too. The legend says that Alexander the Great, on the recommendation of Aristotle, conquered this island for the aloe that he used to cure the wounds of his soldiers.
On the aloe plantation Mon Plaisir, owned by the Frenchman Louis Bazin, a for its time modern steam driven cooking installation was installed, in the beginning of 1900. In the 19th century, Aruba was the main supplier of aloin resin that was mainly used for the production of laxatives. The aloin was exported abroad, mainly to New York, but also to Hamburg and to London. The resin from the Antilles (called `Curaçao resin’ at the time) was one of the best in the world and more expensive than the other types on the market. Aruba’s share in the export of `Curaçao resin’ was over 90%. In the economy of that time, before the arrival of the oil industry, aloe meant a reasonable source of income, in particular for the small ‘cunucero’ (farmer). In times of unemployment – de dry season – the aloe culture was a good source of existence.//

Примерно об этом я и говорил, рассматривая гидроудар как возможный способ попаданческой полимеризации. 🙂

Полимеризация этилена и вулканизация каучука это немного разные вещи.
И если радикальная полимеризация не катит, то есть и катионная, и анионная, и металлокомплексная. Вот например изобутилен, в радикальных системах фиг заполимеризуешь, а с катионным инициатором легко

Я считаю, что для их полимеризации нужны другие условия. Достаточно сравнить синтез полиэтилена и, скажем, вулканизацию каучука.
Да и просто перекисью этилен, к примеру, можно дооолго полимеризовать :).

То есть вы считаете, что несопряженные алкены не полимеризуются?