What role does Hydroxyethyl Methacrylate (HEMA) play in dental adhesives? How does it improve the material's wettability to dentin?

What is the glass transition temperature ($T_g$) of Hydroxyethyl Methacrylate (HEMA)? How does it affect the flexibility of the copolymer?

Is Hydroxyethyl Methacrylate (HEMA) sensitizing? What cytotoxicity testing standards are required for medical device applications?

Why does Hydroxyethyl Methacrylate (HEMA) readily self-polymerize when exposed to light or heat? What is the mechanism of action of MEHQ polymerization inhibitor in Hydroxyethyl Methacrylate (HEMA)?

What is the 'acid value' of Hydroxyethyl Methacrylate (HEMA)? Why is a low acid value crucial for the production of optical-grade polymers?

What are the differences in hydrolysis resistance and curing speed between hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA) in coating formulations?

What are the specific differences in impurity components (such as EGDMA) between industrial-grade Hydroxyethyl Methacrylate (HEMA) (97%+) and optical/medical-grade Hydroxyethyl Methacrylate (HEMA) (99%+)?

What are the consequences of excessively high ethylene glycol dimethacrylate (EGDMA) content in Hydroxyethyl Methacrylate (HEMA) on the crosslinking density of contact lenses? List the major global manufacturers supplying high-purity, extremely low acid value (≤0.05%) Hydroxyethyl Methacrylate (HEMA) and evaluate their reputation in the medical industry.