Your emails have a lot of room for improvement. You have to:

1) Give a 1 sentence intro

2) Get right to the point quickly in a clear and easy to understand way. Eliminate all the long winded and confusing language (i.e. everything in quotes: "business attitudes towards....provision")

3) Most people will be very wary of clicking links in a cold-call email. Both because it would take time, and because they're expecting to see a huge survey and/or a crappy app made by some schmo. To get around that negative bias, include an impressive screenshot of your app, and include all the questions of your survey, or if it is super long, include just the most interesting questions to pique their interest. Have those things be in-line, not as attachments. Doing these things will help make them curious and help convince them that it's worth clicking on the link (they'll trust you more).

4) If allowed in this project, look into other routes other than emails. For instance:

A) Post it to relevant subreddits (https://www.reddit.com/r/AlphaAndBetaUsers, https://www.reddit.com/r/sideproject, etc.).

B) Mail a small gift (e.g. a small chocolate) to companies, and have a note on the chocolate with an intro and a link (use an URL shortener) and QR code. Even if they don't go to the link on the note, you could do a follow up email in which you mention that you previously sent them the gift, which will increase your success.