高分子材料加工技术专业英语 Plastics Materials and Additives 09 Elastomers.pptVIP

下载本文档

5
0
约2.8千字
约 29页
2020-11-14 发布于北京
举报
版权申诉

高分子材料加工技术专业英语 Plastics Materials and Additives 09 Elastomers.ppt

1、有哪些信誉好的足球投注网站（book118）网站文档一经付费（服务费），不意味着购买了该文档的版权，仅供个人/单位学习、研究之用，不得用于商业用途，未经授权，严禁复制、发行、汇编、翻译或者网络传播等，侵权必究。。
2、本站所有内容均由合作方或网友上传，本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺！文档内容仅供研究参考，付费前请自行鉴别。如您付费，意味着您自己接受本站规则且自行承担风险，本站不退款、不进行额外附加服务；查看《如何避免下载的几个坑》。如果您已付费下载过本站文档，您可以点击这里二次下载。
3、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等，请点击“版权申诉”（推荐），也可以打举报电话：400-050-0827(电话支持时间：9:00-18:30)。
4、该文档为VIP文档，如果想要下载，成为VIP会员后，下载免费。
5、成为VIP后，下载本文档将扣除1次下载权益。下载后，不支持退款、换文档。如有疑问请联系我们。
6、成为VIP后，您将拥有八大权益，权益包括：VIP文档下载权益、阅读免打扰、文档格式转换、高级专利检索、专属身份标志、高级客服、多端互通、版权登记。
7、VIP文档为合作方或网友上传，每下载1次，网站将根据用户上传文档的质量评分、类型等，对文档贡献者给予高额补贴、流量扶持。如果你也想贡献VIP文档。上传文档

Elastomers MFG 355 Elastomeric Materials Highly amorphous Highly random orientation High elongation Elastomeric Materials Elastomeric Materials Elastomeric Materials Elastomer Processing Aliphatic Thermoset Elastomers These are the most common elastomers These have a double bond after polymerization has occurred These are noncrystalline These are highly flexible Natural Rubber Natural Rubber Raw material extracted from trees Natural Rubber Material is processed Natural Rubber Latex is then dried, sorted and smoked Natural Rubber The difficulties with natural rubber Strength Availability Bacterial breakdown Creep Natural Rubber Creep Solved by Goodyear in the 1800s Discovered that the polymer could be crosslinked (cured or vulcanized) by heating with sulphur Synthetic Polyisoprene or Isoprene Rubber Need Supply of natural rubber disrupted during WWI and WWII Used in tires for bicycles and early cars Used the Ziegler-Natta catalyst system to improve properties The trans- or cis- nature of the rubber could be controlled up to 90% in either direction Butadiene Rubber (BR) Butadiene Rubber (BR) No cis or trans isomers Lower mechanical strength because of no of pendant methyl group but also more flexibility Lower cost (all synthetic from cheap monomer) Improvement of low-temp flexibility Compatibility with other polymer materials Styrene Butadiene Rubber (SBR) Oil-Resistant Elastomers NBR—Nitrile Butadiene Rubber Copolymerization of butadiene and acrylonitrile More expensive than SBR or BR CR—Chloroprene rubber (neoprene) Thermal stability Non-flammable Thermoplastic Elastomers (EPM and EPDM) Many of the properties of thermoset elastomers Resiliency Elasticity More easily processed Injection molding, extrusion and other standard thermoplastic processes Highly compatible with polyolefins EPDM is crosslinked very lightly and may not be capable of being melted Thermoplastic Olefin Elastomers (TPO) Block tripolymers (such as SBS) with hard and soft domains Poor compatibilit