Polymer degradation and stability

A.Y. 2020/2021
6
Max ECTS
48
Overall hours
SSD
CHIM/04
Language
English
Learning objectives
The aim of this course is to explain the degradation phenomena affecting a polymer during the different phases of its life, from synthesis to processing and disposal, the relative reaction mechanisms in different scenarios, the influence of these phenomena on the physico-chemical properties of that polymer, the main methods of analysis of degradation phenomena and indispensable stabilization processes. Particular attention will be given to the environmental implications of the (bio) degradability of polymers. The aspects relating to combustion and the fire risk in the use of polymers in closed environments, such as means of transport, public and private buildings and workplaces will also be examined in depth.
Expected learning outcomes
Students will know the degradation phenomena affecting a polymer during the different phases of its life and will be able to identify factors that determine the degradation of a polymer and their influence on the resulting physico-chemical properties. They will master main advanced analytical techniques of degradation phenomena, such as high-speed thermogravimetric analysis, flash-pyrolysis and pyrolysis-flow combustion calorimetry and for the study of polymer combustion.
Course syllabus and organization

Single session

Responsible
Lesson period
Second semester
TEACHING METHODS:
The course will be organized with lessons in synchronous mode, using the Microsoft Teams platform according to the second quarter calendar.
It will be also possible to follow the lessons asynchronously as they will be recorded and uploaded on the Ariel platform.
One day a week, the teacher will be available to virtually meet students using a dedicated class on the Microsoft Teams platform to discuss and clarify students' doubts about the contents of a specific lesson and provide further clarification.

COURSE SYLLABUS AND TEACHING RESOURCES:
Attending students must refer to power point presentations for each lesson detailed in the program and uploaded to the Ariel platform.
In addition to the reference texts adopted and already indicated in the Syllabus, extra contents, such as dedicated videos, interviews with academic and industrial experts, and supplementary references materials will be published on the Ariel platform.

ASSESSMENT METHODS AND CRITERIA:
In case of emergency distance teaching, the final exam will be an oral test exploiting the Microsoft Teams platform according to the guidelines provided by the University of Milan.
The exam will consist of an oral examination lasting 30-45 minutes. The timetable with the exam dates will be published promptly and constantly updated in case of need.
The oral test will aim to ascertain the achievement of the objectives in terms of knowledge and understanding. In particular, the evaluation criteria will focus on the ability to answer general questions regarding all the topics covered in the course.
Course syllabus
The course will cover 3 MACRO-TOPICS:

1. The LIFE-CYCLE OF POLYMERS
2. The SERVICE LIFE OF POLYMERS
3. The END-LIFE OF POLYMERS:

1. The LIFE-CYCLE OF POLYMERS.
In this macro-topic the fundamental steps concerning the polymer life, from the synthesis to the processing and transformation in plastics, composites and nanocomposites, their use in daily life, their advantages and disadvantages on the basis of the analysis of European plastic production and demand, will be described.
There will be lessons dedicated to:
o From polymer synthesis to disposal.
o Polymer composites.
o Polymer nanocomposites.

2. The SERVICE LIFE OF POLYMERS.
In this macro-topic, the degradation phenomena affecting a polymer or a polymeric material (composite and nanocomposite) during the different phases of its life will be described.
In particular, the degradation reaction mechanisms in different scenarios due to heat, atmosphere, fire, UV-light, ionizing radiations, and mechanical stress, will be analysed and indispensable stabilization processes will be faced.
There will be lessons dedicated to polymer degradation due to:
o heat (The Service life of polymers (I): thermal degradation);
o oxygen (The Service life of polymers (II): oxidation and stabilization);
o fire (The Service life of polymers (III): fire safety with tradition, with nanotechnology and with bio-based and bio-inspired polymers);
o light (The Service life of polymers (IV): protection against light);
o ionizing radiations (The Service life of polymers (V): protection against ionizing radiations);
o mechanical stress (The Service life of polymers (VI): protection against mechanical stress).

In addition, as specific case study a lesson dedicated to the use of polymers for cultural heritage conservation will be presented. The knowledge of degradation phenomena occurring in the polymers used for this purpose is fundamental. In order to guarantee a high level of protection and conservation for cultural heritage, in fact, it is necessary to select polymers with specific characteristics that respond to the requirements of high stability to light, heat, oxygen, pollution, hydrolysis, cross-linking, and mechanical stress.

3. The END-LIFE OF POLYMERS.
This macro-topic will be dedicated to face the problem concerning plastic disposal. The comparison between fossil-based and bioplastics will be presented from an industrial and environmental point of view referring to the EU waste hierarchy approach. The definitions of biopolymers and bioplastics, biodegradation and composting will be thoroughly detailed together with the description of their characteristics, performances, advantages and disadvantages.
At the end, a lesson focused on the current state of art on the microplastics in the environment will be presented in order to answer to the following questions: what are microplastics and what are their fate and behaviour in the environment? Which factors affecting plastic degradation provoke microplastics formation?
There will be lessons dedicated to:
o fossil-based vs. bioplastics (The End-life of polymers: fossil-based vs. bioplastics);
o microplastics (Microplastics in the environment: the fate of not- restrained polymer degradation).

In addition, during the course 3 lectures dedicated to the main traditional and advanced analytical methods for assessing degradation phenomena will be done:
o Assessment of polymer thermal degradation and oxidation: Traditional vs. advanced analytical methods
o Assessment of polymer combustion
o Assessment of polymer ageing
Prerequisites for admission
The course is intended for students who have attended fundamental courses in chemistry and industrial chemistry, and with some bases in polymer science, and for students who plan to acquire advanced knowledge on the degradation phenomena affecting a polymeric material during the different phases of its life, from the synthesis, to the processing and transformation in plastics, the use (service-life), until the disposal (end-life).
Prerequisites: basic knowledge of organic and physical chemistry, polymer chemistry and science.
Teaching methods
Frontal lessons with the aid of slides (power point presentations) and audio-visual systems (videos).
Teaching Resources
· Slides of the course accompanied by videos dedicated to some topics of the course.
· Scientific papers and reviews on specific topics.
· "Thermal degradation of polymeric materials" of Krzysztof Pielichowski and James Njuguna, edited by Rapra Technology (2005).
· "Flame Retardancy of Polymeric Materials" of C. A. Wilkie and A. B. Morgan, edited by CRC Press (2010).
· "Fire Retardancy of polymeric materials" of A.R. Horrocks and D. Price, edited by CRC Press (2013).
· "Polymer Photodegradation: Mechanisms and Experimental Methods" of Jan F. Rabek, edited by Chapman & Hall (1985).
· "Handbook of Biodegradable Polymers. Synthesis, Characterization and Applications" of A. Lendlein and A. Sisson, edited by Wiley (2011).
Assessment methods and Criteria
The exam will consist of an oral examination lasting 30-45 minutes. The corresponding calendars will be published and constantly updated in the online course.
The oral test will aim to ascertain the achievement of the objectives in terms of knowledge and understanding. In particular, the evaluation criteria will focus on the ability to answer general questions regarding all the topics covered in the course.
Score will vary in the range 18 to 30 out of 30 and will be proportional to the number of correct answers.
The test results will be communicated by e-mail at the end of the exam session and the registration will be conditioned on the acceptance by the student.
CHIM/04 - INDUSTRIAL CHEMISTRY - University credits: 6
Lessons: 48 hours
Professor: Alongi Jenny
Professor(s)
Reception:
Office hours by appointment
Building 5, Body B, 3rd floor, room 3051