Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging and labeling, textiles (e.g., ropes, thermal underwear and carpets), stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes. An addition polymer made from the monomer propylene, it is rugged and unusually resistant to many chemical solvents, bases and acids.
In 2008, the global market for polypropylene had a volume of 45.1 million tonnes, which led to a turnover of about $65 billion (~ €47.4 billion).[1]
聚丙烯（Polypropylene，简称PP）是一种半结晶的热塑性塑料。具有较高的耐冲击性，机械性质强韧，抗多种有机溶剂和酸碱腐蚀。在工业界有广泛的应用，是平常常见的高分子材料之一。澳大利亚的钱币也使用聚丙烯制作。
Most commercial polypropylene is isotactic and has an intermediate level of crystallinity between that of low-density polyethylene (LDPE) and high-density polyethylene (HDPE). Polypropylene is normally tough and flexible, especially when copolymerized with ethylene. This allows polypropylene to be used as an engineering plastic, competing with materials such as ABS. Polypropylene is reasonably economical, and can be made translucent when uncolored but is not as readily made transparent as polystyrene, acrylic, or certain other plastics. It is often opaque or colored using pigments. Polypropylene has good resistance to fatigue.
The melting of polypropylene occurs as a range, so a melting point is determined by finding the highest temperature of a differential scanning calorimetry chart. Perfectly isotactic PP has a melting point of 171 °C (340 °F). Commercial isotactic PP has a melting point that ranges from 160 to 166 °C (320 to 331 °F), depending on atactic material and crystallinity. Syndiotactic PP with a crystallinity of 30% has a melting point of 130 °C (266 °F).[2]
The melt flow rate (MFR) or melt flow index (MFI) is a measure of molecular weight of polypropylene. The measure helps to determine how easily the molten raw material will flow during processing. Polypropylene with higher MFR will fill the plastic mold more easily during the injection or blow-molding production process. As the melt flow increases, however, some physical properties, like impact strength, will decrease.
There are three general types of polypropylene: homopolymer, random copolymer, and block copolymer. The comonomer is typically used with ethylene. Ethylene-propylene rubber or EPDM added to polypropylene homopolymer increases its low temperature impact strength. Randomly polymerized ethylene monomer added to polypropylene homopolymer decreases the polymer crystallinity and makes the polymer more transparent.
[edit]Degradation
Polypropylene is liable to chain degradation from exposure to heat and UV radiation such as that present in sunlight. Oxidation usually occurs at the tertiary carbon atom present in every repeat unit. A free radical is formed here, and then reacts further with oxygen, followed by chain scission to yield aldehydes and carboxylic acids. In external applications, it shows up as a network of fine cracks and crazes that become deeper and more severe with time of exposure.
For external applications, UV-absorbing additives must be used. Carbon black also provides some protection from UV attack. The polymer can also be oxidized at high temperatures, a common problem during molding operations. Anti-oxidants are normally added to prevent polymer degradation.
[edit]History

Propylene was first polymerized to a crystalline isotactic polymer by Giulio Natta as well as by the German chemist Karl Rehn in March 1954.[3] This pioneering discovery led to large-scale commercial production of isotactic polypropylene by the Italian firm Montecatini from 1957 onwards.[4] Syndiotactic polypropylene was also first synthesized by Italian Nobel Prize w

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(荀薇虾13873381713)请问 塑料输液容器用聚丙烯组合盖(拉环式)、塑料输液容器用聚丙烯接口翻译成英语是什么?万分紧急,希望高人指点,谢谢!我也试过在线翻译,但是不准确. ______ Combined with polypropylene plastic containers infusion(塑料输液容器用聚丙烯组合盖) Plastic containers with polypropylene interface infusion(塑料输液容器用聚丙烯接口)

(荀薇虾13873381713)外文翻译需要注意的地方和遵守的原则有哪些? - ______ 任何外文翻译不需遵循的三条黄金原则是:1.信:意思是要忠实于原文的信息,不能改变原文的意思,尤其是翻译科技类,经济类文章,这条很重要2.达:就是要通顺,要尊重目标语言的习惯,比如将英文翻译成中文时,要在坚持“信”的原则下,是翻译更加贴近中文的习惯.3.雅:要有文采.当然这也可以称之为翻译的三种境界,它们三者是相互联系而非矛盾的.

(荀薇虾13873381713)天天酷跑草帽阿鲁和蒙面小强哪个厉害 ______ 阿鲁比较厉害

(荀薇虾13873381713)virgin PP chip 和virgin grade翻译成中文是什么意思?PP是聚丙烯的意思 - ______ 纯聚丙烯芯片 高纯度 virgin 是 纯粹的 例:25 litres Methanol 99.95% Virgin Grade 25升99.95%高纯度甲醇

(荀薇虾13873381713)论文查重中加了引号的也要被查吗?引用了很多东西 不过我都加了引号了 我想知道 查重那个比例 包括引号里的引用在内吗? - ______[答案] 加了引用号,但超过百分之十一样会被检测出来的. 知网检测,就是用一定的算法将你的论文和知网数据库中已收录的论文... (10)外文文献,知网数据库里存储较少.鼓励大家多看外文文献,多学习国外的先进科学知识、工程技术,翻译过来,把它...

(荀薇虾13873381713)写出下列树脂所对应的英文缩写:聚氯乙烯 - 上学吧普法考试 ______ polypropylene 聚丙烯 双语对照 词典结果:polypropylene [英][ˌpɒliˈprəʊpəli:n][美][ˌpɑ:liˈproʊpəli:n] n.聚丙烯; 例句:1.That would be a real advance on polypropylene and sheep's gut. 相对于聚丙烯和羊肠子来说,这的确是一个进步..----------------------------------- 如有疑问欢迎追问!满意请点击右上方【选为满意回答】按钮

(荀薇虾13873381713)polypropylene impact copolymer是什么意思 - ______ polypropylene impact copolymer [英][ˌpɔliˈprəupili:n ˈimpækt kəuˈpɔlimə][美][ˌpɑliˈpropəˌlin ˈɪmˌpækt koˈpɑləmɚ] 聚丙烯抗冲共聚物; 以上结果来自金山词霸

(荀薇虾13873381713)高手翻译printing PVC leather,Opp Printing,Printing leather - ______ PVC 缩写词 abbr. =polyvinyl chloride聚氯乙烯OPP定向聚丙烯=Oriented polypropylene leather printing 皮革压花ps:printing [ˈprintiŋ]n.

(荀薇虾13873381713)聚丙烯纤维俗称丙纶.的翻译是:什么意思 - ______ 翻译成英语是:Polypropylene fiber is commonly called polypropylene fiber