合成纤维的特性
合成纤维和塑料与天然纤维一样,都是由聚合物组成的,它们是非常大的单元。聚合物由许多小块组成。人造丝、尼龙、聚酯和丙烯酸是合成纤维的名称,基于其生产中使用的化学品。不同类型纤维的强度、吸水能力、燃烧性、成本和耐用性各不相同。塑料物品有多种形式和尺寸。塑料无处不在,无论是在室内还是室外。塑料垃圾对环境有负面影响。我们必须以这样一种方式利用合成纤维和塑料,以便我们可以享受它们的好处,同时也尽量减少对生活社区的环境风险。
合成纤维
合成纤维是人造纤维,其中大部分是由被称为石化产品的石油基基础材料制成的。纤维用于制造所有纺织品,它们可以来自天然或人造来源。它们由一个微小的单元或聚合物组成,该单元或聚合物由许多重复单体组成。其中包括尼龙、丙烯酸树脂、聚氨酯和聚丙烯。每年,全世界都会生产数百万吨此类纤维。
What is Polymer?
Synthetic fibres are made by humans and thus are called man-made fibres. They are a chain of small units that are joined together. Here, each small unit is a chemical substance where many small units combine to form a large single unit. This large single unit is called a polymer. The word ‘polymer’ is derived from two Greek words; poly which means many and mer which means part or unit. Therefore, a polymer is made of many repeating units. Synthetic fibres are more durable and affordable which makes them more popular than natural fibres.
合成纤维的分类
衣服和其他各种物品都是由合成纤维制成的。它们可能是完全合成的或有些合成的。天然聚合物用作人造丝等半合成纺织品的起始材料。另一方面,化学品用于制造纯合成纤维。腈纶、聚酯和尼龙都是合成纤维。
人造丝
中国发现了从蚕中提取的丝纤维。这是相当昂贵的。人们对其美丽的质地着迷,因此尝试人工复制它。到十九世纪末,科学家们成功地获得了一种特性类似于丝绸的纤维,这种纤维是通过对木浆进行化学处理而获得的,并被命名为人造丝或人造丝。
人造丝是从天然来源木浆中获得的,但它是一种人造纤维。它也比丝绸便宜,也可以像丝纤维一样编织。它可以染成多种颜色,并与棉花混合制成床单。它也可以与羊毛混合制成地毯。由于其天然来源,人造丝被归类为半合成纤维。由于其纤维细小且重量轻,它有时被称为人造丝。它用于制作衣服、地毯、窗帘和毯子等。
尼龙
尼龙是一种人造纤维,于 1931 年首次制成。它不使用任何天然原料制成,由煤、水和空气制成。这是第一种全合成纤维。尼龙坚固、有弹性且重量轻。它也有光泽,易于清洗。现在很多尼龙制品被用于躺着袜子、绳索、帐篷、牙刷、汽车安全带、睡袋、窗帘等。
聚酯和丙烯酸
聚酯由称为酯的化学物质的重复单元制成。涤纶是一种合成纤维。它不容易起皱,保持清脆。它易于清洗,适合制作服装材料。它的例子是涤纶,这是一种流行的聚酯,可以拉成非常细的纤维,可以像任何其他纱线一样编织。
PET(聚对苯二甲酸乙二醇酯)是一种非常常见的聚酯。 PET 用于制造瓶子、器皿、薄膜、电线等。其中许多不是由天然羊毛制成,但它们看起来像羊毛。它们由称为丙烯酸的合成纤维制成。腈纶衣服很便宜,而且有多种颜色可供选择。
合成纤维的特点和优势
- 它们具有使它们成为服装材料的流行选择的特性。
- 它们更便宜。比天然纤维更坚固耐用。
- 它们具有很高的耐磨性。
- 合成纤维具有高耐磨性。
- 与天然纤维相比,它们吸收的水量更少,因此它们会在更短的时间内变干。
- 它们易于维护和清洗,并且可以抵抗飞蛾的侵袭。
- 合成纤维在洗涤后不会起皱,并且非常轻巧。
- 它们具有非常光滑的质地。
- 它们更实惠。
合成纤维的缺点
- 它们不能吸收水分。因此,它们不适合在我们身体出汗的夏天穿着。
- 它们很容易着火,因此在靠近火源时佩戴它们是危险的。
- 它们不容易熨烫,因为它们很容易融化。
塑料
Plastic is a polymer like synthetic fibre. Some plastic has a linear arrangement while other has cross-linked. Plastic articles are available in all possible shapes and sizes and can be easily moulded in any form. They can be recycled, reused, rolled into sheets or made into wires.
塑料的特性和用途
- 它们是热和电的不良导体。因此,它们被用于制作电线的覆盖层和工具的把手。
- 塑料对化学品和水具有很强的抵抗力。
- 塑料重量轻、坚固耐用。
- 塑料是非反应性的。
- 它是不可生物降解的,需要几年时间才能分解,而且不环保,随着它的日益增多,它是我们关注的一个主要原因。
塑料类型:热塑性塑料和热固性塑料
当水被添加到塑料瓶中时,它会变形。通过这种方法容易变形(即在加热时)并且容易弯曲的塑料被称为热塑性塑料。它的例子是聚乙烯和PVC。它们用于制造玩具、梳子等。
一次成型后加热不能软化的塑料称为热固性塑料。例如电木和三聚氰胺。电木用于制作电器开关、各种器具的把手等。三聚氰胺是一种用途广泛的材料,比其他塑料具有更好的耐火和耐热性。
塑料与环境
通过细菌作用等自然过程分解的材料称为可生物降解的。不易被自然过程分解的材料称为不可生物降解的。塑料需要几年时间才能分解,而且不环保。它会造成环境污染。合成材料的燃烧过程很慢,不容易完全燃烧。燃烧过程会向大气中释放有毒烟雾,造成空气污染。最明显的解决方案是回收塑料。大多数热塑性塑料都可以回收利用。回收的5R原则是Reduce、Reuse、Recycle、Recover和Refuse。
以下是过度使用塑料的问题
- 塑料是不可生物降解的,几年内不会分解。
- 合成材料的燃烧过程很慢,不容易完全燃烧。
- 燃烧时,有毒烟雾会释放到大气中,造成污染。
聚乙烯
Plastic obtained by the polymerization of a chemical compound is called ethene. It is tough and durable. It is used in making polyethene bags, waterproof plastic sheets, bottles, buckets, dustbins and other such things.
聚乙烯的特性
- 它的强度、硬度和刚度都很低。
- 它具有高延展性和冲击强度以及低摩擦。
- 它在持续力下表现出很强的蠕变,可以通过添加短纤维来减少。
- 摸起来有蜡质的感觉。
- 它是一种良好的电绝缘体并提供良好的电阻。
聚乙烯的种类
- 低密度聚乙烯:这些类型的聚乙烯是通过在 350 K - 570 K 的温度下在微量分子氧或过氧化物引发剂存在下进行反应制备的。这样做是为了使其在熔融状态下具有独特的流动性。它们用于制造塑料袋和薄膜包装。
- 高密度聚乙烯:乙烯在烃类溶剂中,333K-343K温度,茂金属催化剂存在下发生加聚反应制得。它们是化学惰性的。惰性意味着它们不会发生反应并用于制造瓶子、黄油桶等。
聚乙烯的用途
- 它们在断裂前具有伸长率,因此可用作塑料,用于成型为各种形状,例如瓶子、片材和管道等。
- 由于它们透明和结晶的性质,它们被用于塑料袋、拉伸膜。
- 它们的预期寿命很高,但会因紫外线辐射而降解。
- 它们具有很高的耐化学性。
聚氯乙烯 (PVC)
PVC is a strong and hard plastic but it is not as flexible as polythene and is used for making insulation for electric wires, pipes, garden hoses, raincoats, seat covers etc. It is made of vinyl chloride monomer by condensation polymerization and it is an example of thermoplastic polymer.
PVC的种类
PVC有两种基本形式,即刚性和柔性。
- 刚性:刚性 PVC 用于管道结构和门窗,以及制造瓶子、非食品包装和银行卡或俱乐部会员卡等卡片。
- 柔韧:柔韧是通过添加增塑剂而变得更加柔软和柔韧。用于管道、电缆绝缘、人造革、地板等。
PVC的特性
- 它具有高硬度,这些性能随着分子量的增加而增强,但随着温度的升高而降低。
- 热稳定性差,需要添加热稳定剂才能保证产品的性能。
- PVC是一种具有良好绝缘性能的聚合物。
- PVC 对酸、盐、碱、脂肪和醇具有化学抗性,使其能够抵抗污水的腐蚀作用。因此,它在下水道管道系统中被大量使用。
胶木
Bakelite is a polymer made up of two monomers- phenol and formaldehyde and is a thermosetting polymer. Bakelite is a very hard and tough plastic but is a poor conductor of heat and electricity. It remains hard on heating. Since it has a low electrical conductivity and high heat resistance it is used in manufacturing electrical switches, plugs and sockets and machine parts of electrical systems.
电木的特性
- 它可以快速成型,并且可以获得非常光滑的成型。
- 电木模制品耐热且耐刮擦。
- 它们还可以抵抗几种破坏性溶剂。
- 电木耐电流。
三聚氰胺
Melamine is a plastic that can tolerate heat much better than other plastics. It can also resist fire. Special plastic cookware made of melamine is used in microwave ovens for cooking food. It contains 67% nitrogen by mass and has fire-retardant properties.
阻燃性能是由于其燃烧时释放氮气。它与甲醛结合生产三聚氰胺树脂。这些树脂是耐用的热固性塑料,用于高压层压板,如三聚氰胺餐具、强化地板等。
铁氟龙
Teflon is a special plastic on which oil and water do not stick because of its slippery surface. It can withstand high temperatures and is used for making soles of electric irons and giving non-stick coating on cookware.
铁氟龙的特性
- 它在室温下是一种碳氟化合物固体。
- 它是疏水的,即它既不是水也不是含水物质湿润的。
铁氟龙的用途
- 用于制作防水面料和不粘炊具。
- 它用于制造减摩装置。
- 用于涂装医疗器械。
- 由于其高抗腐蚀性,它被用于涂装实验室器具的内衬。
示例问题
问题1:什么是聚合物是合成纤维?
回答:
Synthetic fibres are made by human beings and thus are called man-made fibres. A synthetic fibre is a chain of small units joined together where each small unit is a chemical substance. Many small units combine to form a large single unit called a polymer.
问题2:写一个关于尼龙的简短笔记。
回答:
Nylon is a synthetic fibre that was developed in 1931 without the use of any natural raw materials. It was the first fully synthetic fibre, made from coal, water, and air. Nylon is a strong, elastic, and lightweight fibre. It’s glossy and simple to clean. Socks, ropes, tents, toothbrushes, car seat belts, sleeping bags, curtains, and other nylon products are often used nowadays.
问题三:合成纤维有什么特点?
回答:
The characteristics of synthetic fibres are-
- Synthetic fibres possess unique characteristics which make them popular dress materials and are cheaper than natural fibre.
- They are stronger and more durable than natural fibre.
- They dry up in less time.
- They are easy to maintain and wash.
- They are resistant to attack by moths.
问题四:塑料的特性和用途是什么?
回答:
The properties and uses of plastic are,
- Plastic are poor conductors of heat and electricity and thus, they are used to make covering of electric wires and handles of tools.
- Plastics are highly resistant to chemicals and water.
- Plastics are lightweight, strong and durable and are therefore used to make parts for aircrafts, cars etc.
- Plastic is non-reactive.
- It is non-bio degradable, takes several years to decompose and is not environment friendly.
问题 5:区分热塑性塑料和热固性塑料。
回答:
When we add hot water to a plastic bottle, it gets deformed. Plastic which gets deformed easily on heating and can be bent easily is known as thermoplastics. E.g. Polythene and PVC. They are used for manufacturing toys, combs etc.
Plastics which moulded once, can not be softened by heating are called thermosetting plastics. Example- Bakelite and melamine. Bakelite is used for making electrical switches, handles of various utensils, etc.
问题6:塑料对环境有什么影响?
回答:
Plastic takes a long time to disintegrate and is harmful to the environment. It has a negative impact on the environment. The synthetic material’s burning process is sluggish, and it does not simply burn entirely. Poisonous gases are released into the environment during the burning process, resulting in air pollution. Recycling plastic is the most obvious answer. The majority of thermoplastics are recyclable. Reduce, Reuse, Recycle, Recover, and Refuse are the five R’s of recycling.
问题 7:写一个关于聚乙烯、PVC、电木、三聚氰胺和铁氟龙的简短笔记。
回答:
- Polythene- Plastic obtained by the polymerization of a chemical compound is ethene. It is tough and durable and is used in making polythene bags, waterproof plastic sheets, bottles, buckets, dustbins and other such things.
- PVC- PVC is a strong and hard plastic. It is not as flexible as polythene and is used for making insulation for electric wires, pipes, garden hoses, raincoats, seat cover etc. PVC is made of vinyl chloride monomer by condensation polymerization and it is an example of thermoplastic polymer.
- Bakelite- Bakelite is a polymer made up of two monomers- phenol and formaldehyde. It is a thermosetting polymer. Bakelite is a very hard and tough plastic. It is a poor conductor of heat and electricity and it doesn’t become soft on heating.
- Melamine- Melamine is a heat-resistant material that can withstand higher temperatures than other polymers. In microwave ovens, special plastic cookware composed of melamine is used to cook meals.
- Teflon- Teflon is a unique material with a slick surface that prevents oil and water from adhering to it. It can resist high temperatures and is used to make the soles of electric irons and to coat kitchenware with a non-stick coating.