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胶水和胶带哪个更粘 – 译学馆
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胶水和胶带哪个更粘

Which is stronger: Glue or tape? - Elizabeth Cox

世界上最古老的胶水出现在距今八千多年前
The oldest glue in the worldis over 8,000 years old
死海旁边的一个山洞中
and comes from a cave near the Dead Sea.
那时人们使用的胶水
Ancient people used this glue,
由动物骨骼和植物制成
made from a mixture of animal boneand plant materials,
用来制作防水的篮子和一些器皿
to waterproof basketsand construct utensils.
几千年后
And for thousands of years after,
植物和动物成了凝聚人类文明的胶水
plants and animals were the glue that held human civilization together.
现在 我们有无数种胶水和胶带
Today, we have enough types of tape and glue
几乎可以制作修复任何东西
to build and repair almost anything.
但是胶水和胶带的粘性来自哪里?
But what gives glueand tape their stickiness?
二者的粘性是否有强有弱?
And is one stronger than the other?
胶黏剂可以由合成分子制成
Adhesives can be madefrom synthetic molecules
也可以由天然蛋白质或碳水化合物制成
or natural proteins and carbohydrates
比如蔬菜中的淀粉 牛奶中的酪蛋白
like the vegetable starch dextrin, the milk protein casein,
还有树脂中的萜烯
and the terpenes in tree resin.
为了能粘合物体
In order to work,
胶水和胶带都需要含有粘着层和凝结层
glue and tape need both adhesive bonds and cohesive bonds.
粘着层在胶黏分子和
Adhesive bonds occur betweenan adhesive’s molecules
要粘合物体的分子之间
and the moleculesof whatever it’s sticking to.
凝结层则在胶水或者胶带内部的分子之间
Cohesive bonds happen betweena glue or tape’s own molecules,
使得胶黏剂粘合在一起
holding it together.
大多数胶水由聚合物胶黏剂和溶剂组成
Most glues consist of adhesive polymersdissolved in a solvent
溶剂可以防止这些聚合物粘在瓶子里
that prevents them from stickingto the inside of the bottle.
很多胶水的浓烈气味来自溶剂
The strong smell of many gluescomes from the solvent,
这些溶剂暴露在空气中就会蒸发
which evaporates when exposed to air.
有些胶水的溶剂是水
Some glues use water as a solvent,
有些则是对人体有害的化学物质
but others use chemicalsthat can be harmful to inhale.
如果胶水含有不止一种成分
Glues with two or more components
成分之间能发生化学反应 不容易变干
that chemically react instead of just drying
就会有更强的粘性
can create stronger bonds.
胶水的黏着层和凝结层粘性都很强
Both the adhesive and cohesive bondsof glue are strong,
但是干燥过程使得其不能逆转
but the drying processmakes them irreversible.
这就是为何
This is why,
用胶水粘合的表面在胶水干了以后破损
if a glued surface is broken after it dries,
必须用新的胶水才能再次粘合
it can’t be reattached without new glue.
相反 用胶带粘合的表面
By contrast,when tape is applied to a surface,
粘性相对较弱但是可逆
it forms weaker, reversible bonds,
因此胶带使用后可以撕下来
so you can peel a piece of tape
重复利用
off a surface and use it again.
这种弱的粘性叫做范德华力
These weak bonds,called Van der Waals forces,
可以在任意两种材料之间产生
can occur between any two materials,
前提是这两种材料要离得足够近
but only if they’reextremely close together,
距离近到肉眼不可见
closer than the naked eye can see.
胶带通常会有背衬
Tape usually consists of a backing coated
背衬的组成成分包括橡胶
with a combination of a rubber
或像橡胶一样有弹性的东西
or rubber-like”stretchy” component,
还有一种叫增粘剂的化合物
and a compound called a tackifier.
这种化合物就是“粘性”成分
That’s the”sticky” component.
胶带的粘性程度取决于
A tape ’ s stickiness is determined by the proportion
橡胶和增粘剂的比例
of elastic component and tackifier,
还有粘着层渗入背衬的厚度
the thickness of adhesive spreadonto the backing,
以及背衬的材料
and the type of backing material.
胶带贴到物体表面时 没有发生化学反应
No chemical reaction occurswhen tape is pressed onto a surface.
相反 软软的粘着剂只是
Instead, the soft adhesive flows into
流入表面的裂缝和凹槽
the cracks and grooves of the surface.
这种流入裂缝并且留在裂缝的能力
This ability to slide into cracks and then stay in place
叫做粘弹性
is called viscoelasticity.
细小的裂缝一旦被有粘弹性的胶黏剂填满
Once the viscoelastic adhesive fillsthese microscopic crevices,
就很容易产生范德华力了
it is close enough to formVan der Waals forces.
那么世界上最粘的胶黏剂是什么?
So what’s the world’s strongest adhesive?
嗯 这个问题并没有确切的答案
Well, there’s no one answer.
就粘着层的绝对强度来说
In terms of absolute strengthof adhesive bonds,
胶水好于胶带
glue is stronger than tape,
但是胶水也不能完美地应对所有情况
but no single adhesiveworks well in all circumstances.
胶水或强力快干胶中的丙烯酸树脂基粘结剂
Of the glues, cyanoacrylates,or super glues,
粘性或许是最强的
may form the strongest bonds,
但是含两种成分的环氧基树脂胶水
but two-component epoxy glues have much
则更耐热 更耐磨
higher resistance to heat and shearing,
而且适用的表面类型更广泛
and are compatiblewith a wider range of surfaces.
所以 如果你要悬空吊一个铁砧
So, if you wantedto dangle an anvil in the air,
最好选强力胶
super glue might be your best bet.
但是 如果悬空的位置在活火山上方
But if you’re doing soover an active volcano,
那还是选环氧基树脂比较好
you’d want an epoxy instead.
为了能够粘住东西
And in order to work at all,
胶水需要与表面接触的面积足够大
glues need enough real estate where surfaces touch.
要是你万一想
If for some reason you wanted
做一个保龄球链
to make a chain of bowling balls,
那你还是用牛皮胶带比较好
duct tape would be better.
工程师们也是如此权衡的
Engineers weigh similar,
即使不是如此荒谬 还是会常有不同的决定因素
if less absurd, factors all the time.
为引擎选择合适耐热的胶水
Choosing the right glue to withstandthe heat inside an engine
可是性命攸关的大事
is a matter of life and death.
尽管牛皮胶带粘着层的强度
And though the strengthof duct tape’s adhesive bonds
跟环氧胶没法比
can’t compete with those of epoxy glues,
但胶带的优势在于
tape does have the advantage of
它能够即时提供粘性 可以用来应急
instantaneous stickiness in an emergency.
把火箭送入太空可能需要胶水
Glue may be necessaryto get a rocket to space,
但是涉及到太空中的维修
but when it comesto extraterrestrial repairs,
还是用胶带吧
stick to duct tape.
液态的胶水在零重力下无法使用
Liquid glues don’t work in zero gravity.
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