Lightweight particles and compositions containing them

A particle comprising an exterior surface having a coating thereon, wherein the coating comprises:

• (a) a reaction product of an aminoplast resin and the exterior surface;
• and
• (b) the reaction product of (a) and a sulfur-containing polymer wherein the sulfur-containing polymer comprises:
• functional groups reactive with the aminoplast resin;
• and
• functional groups reactive with a film forming binder, a cross-linking agent, or both a film forming binder and a cross-linking agent, wherein the sulfur-containing polymer comprises a thiol-terminated polythioether of Formula (II):
• HS—R1—[—S—(CH2)p—O—[—R2—O—]m—(CH2)2—S—R1—]—SH (II)
• wherein,
• R1 is selected from a C2-6 n-alkylene group;
• a C3-6 branched alkylene group having one or more pendent groups;
• a C6-8 cycloalkylene;
• C6-10 alkylcycloalkylene group;
• heteroatomic substituted analogs of any of the foregoing, —[(—CHR3—)s—O—]q—(—CHR3—)r—, and —[(—CHR3—)s—S—]q—(—CHR3—)r—;
• each R3 is hydrogen;
• m is a rational number having a value ranging from 0 to 50;
• s is an integer having a value ranging from 2 to 6;
• q is an integer having a value ranging from 1 to 5;
• and
• r is an integer having a value ranging from 2 to 10.