Comprehensive studies on the foaming behavior of polypropylene: from microcellular plastics to nanocellular foams

聚丙烯发泡行为的综合研究：从微孔塑料到纳米孔泡沫

• 批准号: 543896-2019
• 负责人: Lee, PatrickChangDong
• 金额: $ 13.32万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=699655
• 关键词: Comprehensive; studies; foaming; behavior; polypropylene

Most commercially available "lightweight" foams are made of commodity plastics, among which polypropylene (PP) is a highly attractive material for foaming as it is inexpensive, easy to process, thermally stable, and mechanically strong. However, the low melt strength of PP presents severe challenges in foaming. Significant advances have been made to enhance the melt strength of PP to produce microcellular foams, but little research has been conducted so far on the foaming under processing conditions that involve a wide range of combinations of nucleating agents and blowing agents. More limited knowledge is available on bubble nucleation in the presence of polymer microstructure (i.e., crystals) during the foaming process. This proposal outlines a comprehensive, systematic study on the foaming behavior of PP-based materials. Unique aspects of the proposed research are: (i) injection of chemical and physical blowing agents as well as their blends to explore the effects of type, loading, and their synergy on foaming; (ii) exploration of various types, sizes, and loadings of mineral nucleating agents and comparison between the performance of mineral and non-mineral type nucleating agents; (iii) visualization of cell nucleation and polymer crystallization during continuous foaming processes to understand the interaction between bubble and crystal nucleation. Canadian plastics product manufacturing industry in 2016 valued at $25.3 billion. Foaming is an effective way to decrease the cost, weight, and environmental impact of plastic products by reducing the amount of raw materials used to make them. Improved fundamental understanding on the foaming process and rigorous studies on various processing conditions thus have tremendous potential to positively impact the rational design of polymeric foaming processes and are expected to provide substantial environmental benefits to Canada. Finally, a good number of highly qualified personnel will be trained during the course of this project. It is greatly anticipated that these trained professionals will eventually bring their proficiency to the Canadian plastic and foam engineering community as well as to academia.

大多数市售“轻质”泡沫均由商品塑料制成，其中聚丙烯（PP）是一种极具吸引力的发泡材料，因为它价格低廉、易于加工、热稳定且机械强度高。然而，PP的低熔体强度给发泡带来了严峻的挑战。在提高聚丙烯熔体强度以生产微孔泡沫方面已经取得了重大进展，但迄今为止，在涉及各种成核剂和发泡剂组合的加工条件下的发泡方面却很少进行研究。关于发泡过程中聚合物微结构（即晶体）存在下的气泡成核，目前的知识还比较有限。 该提案概述了对聚丙烯基材料的发泡行为进行全面、系统的研究。拟议研究的独特之处在于：（i）注入化学和物理发泡剂及其混合物，以探索类型、负载量及其协同作用对发泡的影响； (ii) 探索矿物成核剂的各种类型、尺寸和负载量，并对矿物和非矿物成核剂的性能进行比较； (iii) 连续发泡过程中泡孔成核和聚合物结晶的可视化，以了解气泡和晶体成核之间的相互作用。 2016年加拿大塑料制品制造业产值为253亿加元。发泡是通过减少制造塑料产品的原材料用量来降低塑料产品的成本、重量和环境影响的有效方法。因此，提高对发泡工艺的基本了解以及对各种加工条件的严格研究具有对聚合物发泡工艺的合理设计产生积极影响的巨大潜力，并有望为加拿大带来巨大的环境效益。最后，本项目将培养一大批高素质人才。预计这些经过培训的专业人员最终将把他们的专业知识带到加拿大塑料和泡沫工程界以及学术界。