About Phast
Phast is a UK-based advanced materials company developing the next-generation of sustainable polymers for high-performance applications. Our focus is on creating biobased, microplastic-free materials that can meet stringent mechanical, optical, and biological requirements across regulated industries such as medical and cosmetic.
We are building a new class of materials from the ground up, combining biopolymers with advanced formulation strategies to unlock applications that are currently dominated by fossil-based plastics.
Role Overview
We are seeking a Polymer Chemist with strong expertise in polymer formulations and functionalisation. This role will focus on the development of polymeric formulations for specific medical and cosmetic products, including but not limited UV-curable resins for advanced manufacturing processes.
The successful candidate will play a central role in designing, formulating, and optimising materials to meet demanding performance criteria, while translating laboratory formulations into scalable solutions.
Key Responsibilities
- Design and develop polymeric formulations using biobased polymers
- Design and develop photopolymer resin systems for SLA/DLP processes
- Select and evaluate photoinitiators, reactive diluents, and additives
- Optimise material properties including transparency, mechanical performance, and processability
- Investigate cure kinetics, crosslink density, and network formation
- Conduct material characterisation (mechanical, thermal, rheological, optical)
- Collaborate with external partners to translate formulations into manufactured components
- Support scale-up from lab to pilot production
- Contribute to IP generation and technical strategy
Required Experience
- PhD or equivalent experience in Polymer Chemistry, Materials Science, or Chemical Engineering
- Solid understanding of polymers chemistry, functionalization techniques and properties
- Hands-on experience with photopolymer or UV-curable systems
- Strong background in polymer formulation and optimisation
- Understanding of free radical polymerisation and cure kinetics
- Experience translating materials into real-world applications
Desirable Experience
- Experience with SLA/DLP 3D printing materials
- Familiarity with biopolymers or biodegradable materials
- Exposure to medical or regulated environments
- Experience in scaling materials from lab to production
This is a major role in a startup company, therefore we are looking for strong experimental mindset and problem-solving ability. We are looking for a candidate comfortable to work in a startup environment, where high level of ownership is required. Phast has offices and material processing lab at The Innovation Centre, 217 Portobello street, S1 4DP, Sheffield, UK and uses chemistry facilities within the University of Sheffield premises.
Salary & Benefits
- Type of employment: permanent, full-time (37.5 working hours a week, Monday – Friday)
- Starting date: 1st of July 2026 or earlier
- Salary: £38,000 – £50,000 per annum, depending on experience
- 28 days of annual leave (including bank holidays)
- Life pension scheme company contributed
- Relocation assistance
- Eligible to participate in employee share option scheme
If interested, please email your CV and cover letter to