It was narrated in the ahaadeeth that silk is haraam for men. For example Abu Dawood (3535) narrated that ‘Ali ibn Abi Taalib (may Allaah be pleased with him) said: “The Prophet (peace and blessings of Allaah be upon him) took a piece of silk in his right hand and  a piece of gold in his left and said, ‘These two are forbidden for the males of my ummah.’” Classed as saheeh by al-Albaani in Saheeh Abi Dawood, 3422.

 What is meant by the silk that is forbidden to men is natural silk that is taken from the silkworm. As for artificial silk, that is not included in the prohibition, because there is no statement that it is haraam in either the Qur’aan or Sunnah. If it is not narrated in the Qur’aan and Sunnah that a thing is forbidden, then it is permissible, because the basic principle concerning things is that they are permitted.

 But some of these fabrics made from artificial silk may be very soft and like the fabric worn by women. These should be avoided by men, because what is required of men is to be tough and hard; softness is not appropriate for men.

 See al-Sharh al-Mumti’, 2/207; Tawdeeh al-Ahkaam, 2/447

 And Allaah knows best.  May Allaah send blessings upon our Prophet Muhammad.