Clean Break

UMass Lowell Toxics Use Reduction Institute Laboratory

11:33 AM

TURI’s Hansen Solubility Parameters in Practice (HSPiP) October Challenge: Safely Dissolving PET

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TURI has been using the Hansen Solubility Parameters (HSP) theory for various solvent replacement projects such replacing methylene chloride for paint stripping, but we are hoping to replace other hazardous cleaning solvents. Senior students who have used the Hansen Solubility Parameters in Practice Program (HSPiP) are leaving next year, so we have started training the next generation of TURI students to learn how to use the program to solve real problems in solvent cleaning. Our students, ranging in major from plastics engineering to public health, engaged in the training and wanted more hands-on approach to solving problems. As a learning exercise, the students were given a case study and had to find a safe replacement using the HSPiP Solvent Optimizer.

A Brief Overview of the Hansen Solubility Parameters (HSP) Theory
HSP theory is a theory of solubility rooted in thermodynamics that predicts if a solvent will dissolve a solute. Essentially, the theory boils down to “like dissolves like”. The Hansen Solubility Parameters are based on the strength of a chemical’s intermolecular forces: 
  • London dispersion forces, ẟD
  • Dipole-dipole forces, ẟP 
  • Hydrogen bonding, ẟH

    Each force is quantified by its strength. The three parameters are then mapped in 3D space (Hansen Space), with the solvents represented as points, and the solute represented as a large sphere with an experimentally determined radius (as seen in the photo to the left). If a solvent falls within the sphere, it will dissolve the solute, and if it falls outside the sphere, it will not dissolve the solute. The closer the solvent is to the center of the sphere, the better the dissolution. This is called the Relative Energy Distance (RED) which is calculated in the HSPiP analytical software. The RED is the distance from a solvent to the center of the sphere divided by the radius of the sphere. A RED less than 1 indicates that the solvent is within the sphere and the lower the RED, the more effective the dissolution will be.

HSPiP contains the very useful Solvent Optimizer function. With this theory, there is proportional mixing of the solvents, meaning that if you mix two solvents together in a 1:1 ratio, the new HSP value will be an average of the two HSP values. This gives potential for two solvents outside of the sphere to be mixed together to have a new HSP within the sphere and work as a replacement solvent. The goal is to mix solvents together in a ratio that obtains the lowest RED, which the program does based on the solvents you input. This means that if a hazardous chemical cleans a soil from a surface, we can blend together safer solvents to achieve the same level cleanliness.

Case Study
Students were given the following scenario to try and find a safer substitution using HSPiP:
A company is manufacturing parts by using a polyethylene terephthalate (PET) mold that needs to be dissolved. The company is using methylene chloride at room temperature to dissolve the PET mold. The workers are using proper gloves and eye protection, but no masks. Find a solvent or create a solvent blend using HSPiP that can optimally dissolve the PET mold and is safer for the workers to use.

Details
PET: (18.2, 6.4, 6.6) Radius: 4
·        Methylene chloride’s RED to PET is 0.65
·        Make sure your solvents are liquid at room temperature
·        Make sure the solvents are safe for the workers
·        You do not need to worry about cost of the solvents for this challenge

The submitted replacements were ranked based on their effectiveness, smallest distance to PET, and their safety scores, using TURI’s P2OASys (https://p2oasys.turi.org/).

Submissions
Blend
D
P
H
RED
P2OASys Score
Benzyl Acetoacetate (100%)
18.04
6.47
6.21
0.13
4.300
Butyl Benzoate (50%) Dimethyl Isosorbide (50%)
18
6.4
6.5
0.1
4.200
Butyl Benzoate (50%) Glycerol Triactetate (50%)
17.4
5.1
7.3
0.54
3.950
Benzyl Benzoate (18%) Butyl Benzoate (24%) Dimethyl Isosorbide (58%)
18.2
6.4
6.6
0
4.184
Butyl Benzoate (83%) Caprolactone (8%)
2-Propanol (9%)
18.1
6.4
6.6
0.05
4.314
Butyl Benzoate (82%)
γ-Butyrolactone (7%)
2-Phenoxy Ethanol (11%)
18.2
6.4
6.6
0
4.254
Solvents Proposed:
Benzyl Acetoacetate (CAS: 5396-89-4)
Hazards: SDS indicates none, through a deeper search we found it was a skin irritant, eye irritant, and hazardous to aquatic life.
Butyl Benzoate (CAS: 136-60-7)
Hazards: Acute toxicity, Oral (Category 4), Skin irritation (Category 2), Eye irritation (Category 2A)
Dimethyl Isosorbide (CAS: 5306-85-4)
Hazards: None
Benzyl Benzoate (CAS: 120-51-4)
Hazards: Acute toxicity, Oral (Category 4), Acute aquatic toxicity (Category 1), Chronic aquatic toxicity (Category 1)
Glycerol Triactetate (CAS: 102-76-1)
Hazards: None
Caprolactone (CAS: 502-44-3)
Hazards: Eye irritation (Category 2A)
2-Propanol (CAS: 67-63-0)
Hazards: Flammable liquids (Category 2), Eye irritation (Category 2A), Specific target organ toxicity - single exposure (Category 3), Central nervous system
γ-Butyrolactone (CAS: 96-48-0)
Hazards: Acute toxicity, Oral (Category 4), Serious eye damage (Category 1), Specific target organ toxicity - single exposure (Category 3), Central nervous system
2-Phenoxy Ethanol (CAS: 122-99-6)
Hazards: Acute toxicity, Oral (Category 4), Eye irritation (Category 2A)

Winners
Dan Anspach and Lily Green 2/3 of the winning team!

1st Place: Dan, Lily, and Justin
Benzyl Benzoate (18%) Butyl Benzoate (24%) Dimethyl Isosorbide (58%)
2nd Place: Aaron
Butyl Benzoate (50%) Dimethyl Isosorbide (50%)
3rd Place: Diana and Sabrina
Benzyl Acetoacetate (100%)

All teams participating created safer blends that had and RED less than 0.65; congrats to everyone for learning! Students cited that the hardest part of the challenge was finding solvents within the program that were safe and spent most of their time looking at SDS sheets and toxicology databases. Our first place winners received a $50 Visa gift card and trophies. They will be presenting on their blends at a presentation to the whole TURI staff.

Our November/December HSPiP Challenge will be focusing on a real solvent replacement for TCE for electroplating. The winners of the next challenge will then purchase their solvents and test to see if their solution will work in a realistic setting. They will also receive a $50 Visa gift card and trophies. Stay tuned!

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11:18 AM

Meet TURI's Summer Student Employees!

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TURI provides research and laboratory experiences for UMass Lowell students from a variety of majors. Meet 11 students working in the TURI lab and two students working in the TURI library this summer:

Teddy Kearney, 3rd Year Graduate. Occupational Ergonomics & Occupational Environmental Hygiene

Teddy wanted to pursue an advanced degree that related to his undergraduate degree in Exercise Physiology. He hopes to become a practicing Industrial Hygienist once he graduates from the Master’s Program. He works in the TURI lab on janitorial and industrial projects and does chemical inventory work. “As I work to get a job in the field, I want to get my certification in industrial hygiene to begin helping and protecting workers from work related exposures and hazards.”   

James Keats, Senior, Chemical Engineering

James always wanted to be an engineer but found that he really enjoyed chemistry in high school. Majoring in chemical engineering was his way of combining both disciplines. He hopes to eventually work in the pharmaceutical industry. “I've become better prepared through my work at TURI because it's helped me develop my report writing and problem solving skills,” he says. “It's also taught me a lot about safety and regulation, two things which are very important to work in the pharmaceutical industry.”


Nicole Kebler, Senior, Public Health

Nicole chose to major in public health because, she says, it offers opportunities in many different fields and provides knowledge about health on a population scale rather than on an individual scale. “I’m focusing on the research side of public health and I enjoy researching new information about chemicals and how they can react with the environment and our bodies.” In the TURI lab, she’s working with a colleague on a project to evaluate sustainability and environmental impact of switching to reusable bags. “I hope to continue in the research field and apply the important information and experience I have obtained while working at TURI.”


Lewis Kerrebrock, Graduate, Public Health – Epidemiology

Lewis chose a career in public health because it was a chance for him to make a tangible difference in the world. He works in the TURI library, compiling new research and news articles on subjects including chronic conditions from chemical exposure, environmental recommendations and updates to policy in conservation, chemical regulation, and safety standards. “My experience at TURI will make me more knowledgeable about exposure-based diseases and what ecological conditions to look for when predicting them.” He hopes to work for a state health department, the National Institutes of Health or Centers for Disease Control as an epidemiologist. “As the U.S. disease burden shifts from infectious to chronic, exposure-based diseases are becoming a larger percentage of the national disease burden,” he says.


Adorrah-Le Khan, Senior, Public Health

Aborrah-Le is excited about public health, a field that allows her to study population health through observation and experimentation. “I am hopeful that the strength of public health can continue to increase life expectancy and improve overall quality of life,” she says. “By pursuing a career in epidemiology, my work at TURI helps me to approach issues in public health using alternative perspectives, addressing issues from the point of view of both a health professional and scientist.” She has recently begun collaborating on a research project about reusable bags.

Hagir Mohamed, Doctorate, Biomedical Engineering and Biotechnology Program

Hagir likes to work in research, validating protocols and working on projects and new products. She’s working inn the new microbiology lab at TURI to validate the devices and developing my field trial protocols. A medical doctor in her home country of Sudan, Hagir plans on taking the board exam to get into medical school here. “Working on TURI lab will help me in developing my research skills, validating new labs and qualify me to be more than just a doctor in the future, but with research skills and broader scientific background.”


Kyle Puleo. Junior, Plastics Engineering with a Minor in Biomedical Technology

Kyle has always been fascinated by technology and design. Plastics combined with biomedical technology seemed like the perfect way for him to have a wide-reaching social impact. He works in the TURI Library cataloging articles and Capstone projects so that they can be more easily accessible for those who need to access them. “I hope to be a medical device designer in the future and I believe that my work with TURI will allow me to be more informed about how to make safer medical devices and what alternatives there are to potentially toxic materials.”


Justin Rainaud, Senior, Economics

Justin likes economics because it is influenced by everyone and is always changing. “I enjoy how markets can operate on a global scale and don't have borders,” he says. In the TURI lab, he’s working on media aspects of the lab as well as janitorial testing when needed. In the future, he hopes to work at the Federal Reserve System. “My TURI experience has given me professional communication, team building and time management experiences.”



Harry Rankin, Junior, Chemistry

Harry chose the chemistry track because he is interested in biochemistry and organic chemistry. “Keeping up with the workload can be very rewarding and the classes only get more interesting as the degree progresses,” he says. As research assistant in the TURI lab, he works on janitorial testing and taking inventory of chemicals. “Since TURI is a lab that specializes in toxic reduction, environmental chemistry and green chemistry, I’m exposed to careers in the chemical sciences.”



Jaci Silva Sá, Junior, Chemistry

Jaci loves chemistry for its ability to understand the world. As a TURI lab assistant, he works on janitorial reports and testing. His hope for the future is to work in the food industry field to find ways to improve areas like food waste. “Working at TURI prepares me for my future career by allowing me to practice skills such as writing reports and research. The experience also reinforces safety practices, which are habits that are needed for any work environment.”



Kevin Smith, Senior, Chemistry

Kevin is interested in chemistry because it offers a real, physical explanation for the world around us. “I find the idea incredible that we can create new molecules to better suit our needs in society.” He is focusing his undergraduate studies within organic chemistry and synthesis. He’s been working on janitorial and industrial testing for TURI as well as contributing to finalizing the setup of the new lab facility at Boott Mills. “In the future, I hope to work as a research chemist within organic or biochemistry and TURI will help me get there by giving me years of wet lab experience.”

Vinh Tran ‘17, BS in Business Administration, Supply Chain Management; Freshman, Biomedical Engineering, Fall 2018.

After earning a bachelor’s degree in business, Vinh Tran’s work in the TURI lab for five years has influenced his next degree choice. “Working at TURI has given me a renewed sense of direction, making me realize that I wanted to pursue a career in STEM,” He will study biomedical engineering in the fall. “I wish to actively improve the quality of life of humanity through tangible means by way of medical devices. I’ve been immersed in a professional laboratory setting at TURI, collaborating with coworkers to complete experiments. I’ve been project lead for a number of tests, all of which I know will prepare me for my future career.”

Othon Pagounes, Junior, Biomedical Engineering

Othon is interested in biomedical engineering because it combines both engineering and biology to help improve people's lives. In the TURI Lab, he works as lab assistant, producing janitorial reports and conducting testing. “I hope to work in a medical device company one day,” he says. “The wet lab, writing of reports and research skills I have gained at TURI will add to the tools I've learned at UML to make me a better engineer.”


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