You currently don’t have a section 2 Research question and research sub questions. If your Literature review isn’t investigating a question it is difficult to assess how good, it is. The question is also a good may to assess whether your research is supporting or contradicting your claim.
“What are the alternative vegan fabrics to mainstream animal-based fabrics such as wool, leather, fur and silk?”
This is a really interesting area of research, but I think your question is more than just introducing alternative fabrics and materials. The area of disagreement seems to be what is vegan; What is Ethical; What is sustainable; and what is environmental friendly? This conflict between sides that ultimately agree seem to be what you need to focus on.
The inconsistency between the ideas is where you can show the discussion. Wearing wool is unethical, however, it is a biproduct of an animal and the animal is not harmed. When the garment is finishing the material will naturally decompose. However, a customer may choose a vegan garment made of recycled plastic, but when they have finished wearing it the item will go to landfill and not breakdown for thousands of years. Plastic mirco-fibres from clothes are also thought to enter our water system and enter the food chain. Is wearing wool better than wearing plastic!
Look at data on the amount of clothing that goes to landfill. If sheep weren’t being kept for their meat or their wool what would be the reason for having them? Large scale veganism could see certain animals only being kept as pets. Cotton is a vegan material, but it doesn’t mean that it has been produced in an ethical or sustainable way.
What is the size of the fashion material industry (wool, leather, fur and silk). What impact are these new materials having on the industry? How has vegan clothing become more prominent? Do audiences know what vegan clothing is? Have fashion designers produced vegan collections?
The ethical, sustainable and bio-degradable materials you have identified are really good ideas however, how sustainable are they? Can they product a material in the numbers needed? Everyone agrees that Wind turbines are a good source of renewable energy, however, you need thousands of them to match the amount of energy of a single nuclear power station