Angular Form Required doesn't work

I put a simple form input in my form but required doesn't work for me and from with empty input submitted. Here is my code:

<div class="form-group">
    <div class="col-sm-offset-2 col-sm-10">
      <input type="text" class="form-control" id="inputEmail3" placeholder="test" 
        required
        name="test">
    </div>
  </div>

Here is my form tag:

<form class="form-horizontal" (ngSubmit)="onSubmit()">

Here is my submit button tag:

<button type="submit" class="btn btn-default">Save</button>