Reactive from

import { FormGroup, FormBuilder } from '@angular/forms';

form: FormGroup;
model: OrganizationAddModel;

constructor(private formBuilder: FormBuilder, private organizationService: OrganizationService) {
    this.model = new OrganizationAddModel();
}

ngOnInit() {
this.form = this.formBuilder.group({
name:[],
email:[]     
});
}

<form [formGroup]="form">
<input [(ngModel)]="model.name" formControlName="name" matInput placeholder="Name">
  <div *ngIf="form.controls.name.invalid">
{{form.controls.name.errors.message}}
</div>
<input  [(ngModel)]="model.email" formControlName="email" matInput placeholder="Email">
</form>

let controls = this.form.controls;       
for (var field in controls) {         
   controls[field].setErrors({
message: "This is required field"
});
}