Latex

Natural rubber

Latex (or latex) is the raw material from which innumerable natural rubber products originate: it is a milky liquid with a rubbery and extremely elastic consistency, extracted from some superior plants (angiosperms). Due to its extraordinary properties, latex is widely used in the health, construction and domestic sectors, as well as in the toy sector.

In recent years, latex is increasingly capturing the attention of scholars and researchers: this milky substance, apparently harmless, is in fact involved in numerous allergic processes, also responsible for serious adverse reactions. Latex allergy is a growing health problem: hence the need to create products with different materials than latex, trying to imitate as much as possible the prodigious elastic characteristics.

Generality

The tropical rubber tree ( Hevea Brasiliensis or rubber tree) is the primary source from which latex is extracted.

However, this substance is also derived from other higher plants (phylum: Angiosperme ) - papaveraceae, moraine, composite, euphorbiaceae - and some fungi (gen. Lactarius ).

The latex is obtained from the incision of the trunk of some angiosperms: the liquid flows in a complex system of canals and canaliculi inside the plant, precisely in the "laticiferous" vessels of roots, stems, stem, leaves and (sometimes) fruits. Inside these ducts, the latex is subjected to a certain pressure: this explains why, following a small incision in the shaft of a rubber tree, the latex gushes and gushes easily. When in contact with air, the liquid is altered and tends to coagulate.

From the chemical point of view, latex is a complex emulsion consisting of:

• water (60%)
• rubber (35%)
• proteins and enzymes (3%) → eveine proteins are allergens involved in allergic reactions to latex
• other molecules: resins, hydrocarbons, starch granules, secondary metabolites (alkaloids), inorganic salts (2%)

The composition of the latex just reported is approximate: each species from which the latex is obtained has its own specific mixture of substances.

Latex has a rubbery and extremely elastic appearance. The latex proper (latex) has a milky-white appearance, although it is often orange-colored, yellowish or even red-purple. The milky liquid appears dense, viscous and sticky.

Properties and applications

Latex is extremely useful for the plant that produces it: the milky liquid, in fact, exerts excellent properties DEFENSIVE from the attack of herbivorous animals. The sticky consistency of latex allows the plant to trap many insects and small animals, preventing them from taking advantage of the plant itself.

The latex also exerts excellent ANTIBACTERIAL, anti-mold and fungicidal properties: for this reason, latex is a material widely used to make mattresses and countless sanitary items.

But the most important property - and the most well-known - recognized to latex is the ELASTICIZING one: it seems that this liquid is, by far, the most elastic known in nature. Immediately after being subjected to elongation or pressure, the latex summarizes its original shape: hence we can understand the reason why latex is widely used to make gloves and elastic bands.

The latex can be produced by synthesis, polymerizing the styrene monomer, which is subsequently emulsified with specific surfactants.

Latex is widely used as a raw material; during the manufacturing process, additives (thiuram, thiourea, ethyl carbamate), which are also involved in allergies, are often added to the latex.

There are countless objects in common use made with latex: just think that every year 7 million tons of latex are extracted, later exploited to make 40, 000 objects of every shape and every kind.

Let's see the most common in the table.

CATEGORY OF MEMBERSHIP	OBJECTS
Furniture and objects for domestic use	Adhesives, hot water bottles, latex foam pillows, rubber bands, gloves, gaskets, window insulation, mattresses, shower curtains
Toys / baby products	Pacifiers, balloons, games, diapers, teats
garments	Belts, suspenders, gloves, shoes, elastic bandages, bras
Sporting objects	Boat accessories, underwater masks, balls, fins, sole for tennis shoes
contraceptives	Condoms, diaphragms
Mechanics	Tires
Objects for the hospital environment	Agocannulas, orthodontic appliances, bladder catheters, eye dropper droppers, adhesive suction pads, compression straps, tourniquets, urinary support bags, sphygmomanometer, stethoscope, endotracheal / nasopharyngeal tubes, artificial respiration valves, etc.
Chewing gum	The latex obtained from some particular trees ( Manilkara chicle, in Colombia and Dyera costulata, in Malaysia and in Thailand ) is used to make chewingum

The objects shown in the table are just some of the countless products made with latex. An individual who is allergic to it must always bear in mind the list of "at risk" objects: serious allergic reactions to latex can degenerate into anaphylactic shock.

Latex and medical use

From the incision of the immature capsules of Papaver somniferum it is possible to extract the latex, from which, in turn, the opium is obtained.

Latex extracted from fig ( Ficus carica L) and celandine ( Chelidonium majus L) is also used for "therapeutic" purposes, as a natural remedy for treating warts and treating warts.